Kimurai is a modern web scraping framework written in Ruby which works out of box with Headless Chromium/Firefox, PhantomJS, or simple HTTP requests and allows to scrape and interact with JavaScript rendered websites
UPD. I will soon have a time to work on issues for current 1.4 version and also plan to release new 2.0 version with https://github.com/twalpole/apparition engine.
Kimurai is a modern web scraping framework written in Ruby which works out of box with Headless Chromium/Firefox, PhantomJS, or simple HTTP requests and allows to scrape and interact with JavaScript rendered websites.
Kimurai based on well-known Capybara and Nokogiri gems, so you don’t have to learn anything new. Lets see:
# github_spider.rb
require 'kimurai'
class GithubSpider < Kimurai::Base
@name = "github_spider"
@engine = :selenium_chrome
@start_urls = ["https://github.com/search?q=Ruby%20Web%20Scraping"]
@config = {
user_agent: "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.84 Safari/537.36",
before_request: { delay: 4..7 }
}
def parse(response, url:, data: {})
response.xpath("//ul[@class='repo-list']/div//h3/a").each do |a|
request_to :parse_repo_page, url: absolute_url(a[:href], base: url)
end
if next_page = response.at_xpath("//a[@class='next_page']")
request_to :parse, url: absolute_url(next_page[:href], base: url)
end
end
def parse_repo_page(response, url:, data: {})
item = {}
item[:owner] = response.xpath("//h1//a[@rel='author']").text
item[:repo_name] = response.xpath("//h1/strong[@itemprop='name']/a").text
item[:repo_url] = url
item[:description] = response.xpath("//span[@itemprop='about']").text.squish
item[:tags] = response.xpath("//div[@id='topics-list-container']/div/a").map { |a| a.text.squish }
item[:watch_count] = response.xpath("//ul[@class='pagehead-actions']/li[contains(., 'Watch')]/a[2]").text.squish
item[:star_count] = response.xpath("//ul[@class='pagehead-actions']/li[contains(., 'Star')]/a[2]").text.squish
item[:fork_count] = response.xpath("//ul[@class='pagehead-actions']/li[contains(., 'Fork')]/a[2]").text.squish
item[:last_commit] = response.xpath("//span[@itemprop='dateModified']/*").text
save_to "results.json", item, format: :pretty_json
end
end
GithubSpider.crawl!
$ ruby github_spider.rbI, [2018-08-22 13:08:03 +0400#15477] [M: 47377500980720] INFO -- github_spider: Spider: started: github_spider
D, [2018-08-22 13:08:03 +0400#15477] [M: 47377500980720] DEBUG -- github_spider: BrowserBuilder (selenium_chrome): created browser instance
D, [2018-08-22 13:08:03 +0400#15477] [M: 47377500980720] DEBUG -- github_spider: BrowserBuilder (selenium_chrome): enabled `browser before_request delay`
D, [2018-08-22 13:08:03 +0400#15477] [M: 47377500980720] DEBUG -- github_spider: Browser: sleep 7 seconds before request...
D, [2018-08-22 13:08:10 +0400#15477] [M: 47377500980720] DEBUG -- github_spider: BrowserBuilder (selenium_chrome): enabled custom user-agent
D, [2018-08-22 13:08:10 +0400#15477] [M: 47377500980720] DEBUG -- github_spider: BrowserBuilder (selenium_chrome): enabled native headless_mode
I, [2018-08-22 13:08:10 +0400#15477] [M: 47377500980720] INFO -- github_spider: Browser: started get request to: https://github.com/search?q=Ruby%20Web%20Scraping
I, [2018-08-22 13:08:26 +0400#15477] [M: 47377500980720] INFO -- github_spider: Browser: finished get request to: https://github.com/search?q=Ruby%20Web%20Scraping
I, [2018-08-22 13:08:26 +0400#15477] [M: 47377500980720] INFO -- github_spider: Info: visits: requests: 1, responses: 1
D, [2018-08-22 13:08:27 +0400#15477] [M: 47377500980720] DEBUG -- github_spider: Browser: driver.current_memory: 107968
D, [2018-08-22 13:08:27 +0400#15477] [M: 47377500980720] DEBUG -- github_spider: Browser: sleep 5 seconds before request...
I, [2018-08-22 13:08:32 +0400#15477] [M: 47377500980720] INFO -- github_spider: Browser: started get request to: https://github.com/lorien/awesome-web-scraping
I, [2018-08-22 13:08:33 +0400#15477] [M: 47377500980720] INFO -- github_spider: Browser: finished get request to: https://github.com/lorien/awesome-web-scraping
I, [2018-08-22 13:08:33 +0400#15477] [M: 47377500980720] INFO -- github_spider: Info: visits: requests: 2, responses: 2
D, [2018-08-22 13:08:33 +0400#15477] [M: 47377500980720] DEBUG -- github_spider: Browser: driver.current_memory: 212542
D, [2018-08-22 13:08:33 +0400#15477] [M: 47377500980720] DEBUG -- github_spider: Browser: sleep 4 seconds before request...
I, [2018-08-22 13:08:37 +0400#15477] [M: 47377500980720] INFO -- github_spider: Browser: started get request to: https://github.com/jaimeiniesta/metainspector
...
I, [2018-08-22 13:23:07 +0400#15477] [M: 47377500980720] INFO -- github_spider: Browser: started get request to: https://github.com/preston/idclight
I, [2018-08-22 13:23:08 +0400#15477] [M: 47377500980720] INFO -- github_spider: Browser: finished get request to: https://github.com/preston/idclight
I, [2018-08-22 13:23:08 +0400#15477] [M: 47377500980720] INFO -- github_spider: Info: visits: requests: 140, responses: 140
D, [2018-08-22 13:23:08 +0400#15477] [M: 47377500980720] DEBUG -- github_spider: Browser: driver.current_memory: 204198
I, [2018-08-22 13:23:08 +0400#15477] [M: 47377500980720] INFO -- github_spider: Browser: driver selenium_chrome has been destroyed
I, [2018-08-22 13:23:08 +0400#15477] [M: 47377500980720] INFO -- github_spider: Spider: stopped: {:spider_name=>"github_spider", :status=>:completed, :environment=>"development", :start_time=>2018-08-22 13:08:03 +0400, :stop_time=>2018-08-22 13:23:08 +0400, :running_time=>"15m, 5s", :visits=>{:requests=>140, :responses=>140}, :error=>nil}
[
{
"owner": "lorien",
"repo_name": "awesome-web-scraping",
"repo_url": "https://github.com/lorien/awesome-web-scraping",
"description": "List of libraries, tools and APIs for web scraping and data processing.",
"tags": [
"awesome",
"awesome-list",
"web-scraping",
"data-processing",
"python",
"javascript",
"php",
"ruby"
],
"watch_count": "159",
"star_count": "2,423",
"fork_count": "358",
"last_commit": "4 days ago",
"position": 1
},
...
{
"owner": "preston",
"repo_name": "idclight",
"repo_url": "https://github.com/preston/idclight",
"description": "A Ruby gem for accessing the freely available IDClight (IDConverter Light) web service, which convert between different types of gene IDs such as Hugo and Entrez. Queries are screen scraped from http://idclight.bioinfo.cnio.es.",
"tags": [
],
"watch_count": "6",
"star_count": "1",
"fork_count": "0",
"last_commit": "on Apr 12, 2012",
"position": 127
}
]
Okay, that was easy. How about javascript rendered websites with dynamic HTML? Lets scrape a page with infinite scroll:
# infinite_scroll_spider.rb
require 'kimurai'
class InfiniteScrollSpider < Kimurai::Base
@name = "infinite_scroll_spider"
@engine = :selenium_chrome
@start_urls = ["https://infinite-scroll.com/demo/full-page/"]
def parse(response, url:, data: {})
posts_headers_path = "//article/h2"
count = response.xpath(posts_headers_path).count
loop do
browser.execute_script("window.scrollBy(0,10000)") ; sleep 2
response = browser.current_response
new_count = response.xpath(posts_headers_path).count
if count == new_count
logger.info "> Pagination is done" and break
else
count = new_count
logger.info "> Continue scrolling, current count is #{count}..."
end
end
posts_headers = response.xpath(posts_headers_path).map(&:text)
logger.info "> All posts from page: #{posts_headers.join('; ')}"
end
end
InfiniteScrollSpider.crawl!
$ ruby infinite_scroll_spider.rbI, [2018-08-22 13:32:57 +0400#23356] [M: 47375890851320] INFO -- infinite_scroll_spider: Spider: started: infinite_scroll_spider
D, [2018-08-22 13:32:57 +0400#23356] [M: 47375890851320] DEBUG -- infinite_scroll_spider: BrowserBuilder (selenium_chrome): created browser instance
D, [2018-08-22 13:32:57 +0400#23356] [M: 47375890851320] DEBUG -- infinite_scroll_spider: BrowserBuilder (selenium_chrome): enabled native headless_mode
I, [2018-08-22 13:32:57 +0400#23356] [M: 47375890851320] INFO -- infinite_scroll_spider: Browser: started get request to: https://infinite-scroll.com/demo/full-page/
I, [2018-08-22 13:33:03 +0400#23356] [M: 47375890851320] INFO -- infinite_scroll_spider: Browser: finished get request to: https://infinite-scroll.com/demo/full-page/
I, [2018-08-22 13:33:03 +0400#23356] [M: 47375890851320] INFO -- infinite_scroll_spider: Info: visits: requests: 1, responses: 1
D, [2018-08-22 13:33:03 +0400#23356] [M: 47375890851320] DEBUG -- infinite_scroll_spider: Browser: driver.current_memory: 95463
I, [2018-08-22 13:33:05 +0400#23356] [M: 47375890851320] INFO -- infinite_scroll_spider: > Continue scrolling, current count is 5...
I, [2018-08-22 13:33:18 +0400#23356] [M: 47375890851320] INFO -- infinite_scroll_spider: > Continue scrolling, current count is 9...
I, [2018-08-22 13:33:20 +0400#23356] [M: 47375890851320] INFO -- infinite_scroll_spider: > Continue scrolling, current count is 11...
I, [2018-08-22 13:33:26 +0400#23356] [M: 47375890851320] INFO -- infinite_scroll_spider: > Continue scrolling, current count is 13...
I, [2018-08-22 13:33:28 +0400#23356] [M: 47375890851320] INFO -- infinite_scroll_spider: > Continue scrolling, current count is 15...
I, [2018-08-22 13:33:30 +0400#23356] [M: 47375890851320] INFO -- infinite_scroll_spider: > Pagination is done
I, [2018-08-22 13:33:30 +0400#23356] [M: 47375890851320] INFO -- infinite_scroll_spider: > All posts from page: 1a - Infinite Scroll full page demo; 1b - RGB Schemes logo in Computer Arts; 2a - RGB Schemes logo; 2b - Masonry gets horizontalOrder; 2c - Every vector 2016; 3a - Logo Pizza delivered; 3b - Some CodePens; 3c - 365daysofmusic.com; 3d - Holograms; 4a - Huebee: 1-click color picker; 4b - Word is Flickity is good; Flickity v2 released: groupCells, adaptiveHeight, parallax; New tech gets chatter; Isotope v3 released: stagger in, IE8 out; Packery v2 released
I, [2018-08-22 13:33:30 +0400#23356] [M: 47375890851320] INFO -- infinite_scroll_spider: Browser: driver selenium_chrome has been destroyed
I, [2018-08-22 13:33:30 +0400#23356] [M: 47375890851320] INFO -- infinite_scroll_spider: Spider: stopped: {:spider_name=>"infinite_scroll_spider", :status=>:completed, :environment=>"development", :start_time=>2018-08-22 13:32:57 +0400, :stop_time=>2018-08-22 13:33:30 +0400, :running_time=>"33s", :visits=>{:requests=>1, :responses=>1}, :error=>nil}
click_on, fill_in, select, choose, set, go_back, etc. to interact with web pagesin_parallelkimurai setup and kimurai deploy (Ansible under the hood)Kimurai requires Ruby version >= 2.5.0. Supported platforms: Linux and Mac OS X.
# Install required packages for ruby-build
sudo apt update
sudo apt install git-core curl zlib1g-dev build-essential libssl-dev libreadline-dev libreadline6-dev libyaml-dev libxml2-dev libxslt1-dev libcurl4-openssl-dev libffi-dev
# Install rbenv and ruby-build
cd && git clone https://github.com/rbenv/rbenv.git ~/.rbenv
echo 'export PATH="$HOME/.rbenv/bin:$PATH"' >> ~/.bashrc
echo 'eval "$(rbenv init -)"' >> ~/.bashrc
exec $SHELL
git clone https://github.com/rbenv/ruby-build.git ~/.rbenv/plugins/ruby-build
echo 'export PATH="$HOME/.rbenv/plugins/ruby-build/bin:$PATH"' >> ~/.bashrc
exec $SHELL
# Install latest Ruby
rbenv install 2.5.3
rbenv global 2.5.3
gem install bundler
# Install homebrew if you don't have it https://brew.sh/
# Install rbenv and ruby-build:
brew install rbenv ruby-build
# Add rbenv to bash so that it loads every time you open a terminal
echo 'if which rbenv > /dev/null; then eval "$(rbenv init -)"; fi' >> ~/.bash_profile
source ~/.bash_profile
# Install latest Ruby
rbenv install 2.5.3
rbenv global 2.5.3
gem install bundler
Install Kimurai gem: $ gem install kimurai
Install browsers with webdrivers:
Note: for Ubuntu 16.04-18.04 there is available automatic installation using setup command:
$ kimurai setup localhost --local --ask-sudo
It works using Ansible so you need to install it first: $ sudo apt install ansible. You can check using playbooks here.
If you chose automatic installation, you can skip following and go to “Getting To Know” part. In case if you want to install everything manually:
# Install basic tools
sudo apt install -q -y unzip wget tar openssl
# Install xvfb (for virtual_display headless mode, in additional to native)
sudo apt install -q -y xvfb
# Install chromium-browser and firefox
sudo apt install -q -y chromium-browser firefox
# Instal chromedriver (2.44 version)
# All versions located here https://sites.google.com/a/chromium.org/chromedriver/downloads
cd /tmp && wget https://chromedriver.storage.googleapis.com/2.44/chromedriver_linux64.zip
sudo unzip chromedriver_linux64.zip -d /usr/local/bin
rm -f chromedriver_linux64.zip
# Install geckodriver (0.23.0 version)
# All versions located here https://github.com/mozilla/geckodriver/releases/
cd /tmp && wget https://github.com/mozilla/geckodriver/releases/download/v0.23.0/geckodriver-v0.23.0-linux64.tar.gz
sudo tar -xvzf geckodriver-v0.23.0-linux64.tar.gz -C /usr/local/bin
rm -f geckodriver-v0.23.0-linux64.tar.gz
# Install PhantomJS (2.1.1)
# All versions located here http://phantomjs.org/download.html
sudo apt install -q -y chrpath libxft-dev libfreetype6 libfreetype6-dev libfontconfig1 libfontconfig1-dev
cd /tmp && wget https://bitbucket.org/ariya/phantomjs/downloads/phantomjs-2.1.1-linux-x86_64.tar.bz2
tar -xvjf phantomjs-2.1.1-linux-x86_64.tar.bz2
sudo mv phantomjs-2.1.1-linux-x86_64 /usr/local/lib
sudo ln -s /usr/local/lib/phantomjs-2.1.1-linux-x86_64/bin/phantomjs /usr/local/bin
rm -f phantomjs-2.1.1-linux-x86_64.tar.bz2
# Install chrome and firefox
brew cask install google-chrome firefox
# Install chromedriver (latest)
brew cask install chromedriver
# Install geckodriver (latest)
brew install geckodriver
# Install PhantomJS (latest)
brew install phantomjs
Also, if you want to save scraped items to the database (using ActiveRecord, Sequel or MongoDB Ruby Driver/Mongoid), you need to install database clients/servers:
SQlite: $ sudo apt -q -y install libsqlite3-dev sqlite3.
If you want to connect to a remote database, you don’t need database server on a local machine (only client):
# Install MySQL client
sudo apt -q -y install mysql-client libmysqlclient-dev
# Install Postgres client
sudo apt install -q -y postgresql-client libpq-dev
# Install MongoDB client
sudo apt install -q -y mongodb-clients
But if you want to save items to a local database, database server required as well:
# Install MySQL client and server
sudo apt -q -y install mysql-server mysql-client libmysqlclient-dev
# Install Postgres client and server
sudo apt install -q -y postgresql postgresql-contrib libpq-dev
# Install MongoDB client and server
# version 4.0 (check here https://docs.mongodb.com/manual/tutorial/install-mongodb-on-ubuntu/)
sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 9DA31620334BD75D9DCB49F368818C72E52529D4
# for 16.04:
# echo "deb [ arch=amd64,arm64 ] https://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/4.0 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-4.0.list
# for 18.04:
echo "deb [ arch=amd64 ] https://repo.mongodb.org/apt/ubuntu bionic/mongodb-org/4.0 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-4.0.list
sudo apt update
sudo apt install -q -y mongodb-org
sudo service mongod start
SQlite: $ brew install sqlite3
# Install MySQL client and server
brew install mysql
# Start server if you need it: brew services start mysql
# Install Postgres client and server
brew install postgresql
# Start server if you need it: brew services start postgresql
# Install MongoDB client and server
brew install mongodb
# Start server if you need it: brew services start mongodb
Before you get to know all Kimurai features, there is $ kimurai console command which is an interactive console where you can try and debug your scraping code very quickly, without having to run any spider (yes, it’s like Scrapy shell).
$ kimurai console --engine selenium_chrome --url https://github.com/vifreefly/kimuraframework
$ kimurai console --engine selenium_chrome --url https://github.com/vifreefly/kimuraframework
D, [2018-08-22 13:42:32 +0400#26079] [M: 47461994677760] DEBUG -- : BrowserBuilder (selenium_chrome): created browser instance
D, [2018-08-22 13:42:32 +0400#26079] [M: 47461994677760] DEBUG -- : BrowserBuilder (selenium_chrome): enabled native headless_mode
I, [2018-08-22 13:42:32 +0400#26079] [M: 47461994677760] INFO -- : Browser: started get request to: https://github.com/vifreefly/kimuraframework
I, [2018-08-22 13:42:35 +0400#26079] [M: 47461994677760] INFO -- : Browser: finished get request to: https://github.com/vifreefly/kimuraframework
D, [2018-08-22 13:42:35 +0400#26079] [M: 47461994677760] DEBUG -- : Browser: driver.current_memory: 201701
From: /home/victor/code/kimurai/lib/kimurai/base.rb @ line 189 Kimurai::Base#console:
188: def console(response = nil, url: nil, data: {})
=> 189: binding.pry
190: end
[1] pry(#<Kimurai::Base>)> response.xpath("//title").text
=> "GitHub - vifreefly/kimuraframework: Modern web scraping framework written in Ruby which works out of box with Headless Chromium/Firefox, PhantomJS, or simple HTTP requests and allows to scrape and interact with JavaScript rendered websites"
[2] pry(#<Kimurai::Base>)> ls
Kimurai::Base#methods: browser console logger request_to save_to unique?
instance variables: @browser @config @engine @logger @pipelines
locals: _ __ _dir_ _ex_ _file_ _in_ _out_ _pry_ data response url
[3] pry(#<Kimurai::Base>)> ls response
Nokogiri::XML::PP::Node#methods: inspect pretty_print
Nokogiri::XML::Searchable#methods: % / at at_css at_xpath css search xpath
Enumerable#methods:
all? collect drop each_with_index find_all grep_v lazy member? none? reject slice_when take_while without
any? collect_concat drop_while each_with_object find_index group_by many? min one? reverse_each sort to_a zip
as_json count each_cons entries first include? map min_by partition select sort_by to_h
chunk cycle each_entry exclude? flat_map index_by max minmax pluck slice_after sum to_set
chunk_while detect each_slice find grep inject max_by minmax_by reduce slice_before take uniq
Nokogiri::XML::Node#methods:
<=> append_class classes document? has_attribute? matches? node_name= processing_instruction? to_str
== attr comment? each html? name= node_type read_only? to_xhtml
> attribute content elem? inner_html namespace= parent= remove traverse
[] attribute_nodes content= element? inner_html= namespace_scopes parse remove_attribute unlink
[]= attribute_with_ns create_external_subset element_children inner_text namespaced_key? path remove_class values
accept before create_internal_subset elements internal_subset native_content= pointer_id replace write_html_to
add_class blank? css_path encode_special_chars key? next prepend_child set_attribute write_to
add_next_sibling cdata? decorate! external_subset keys next= previous text write_xhtml_to
add_previous_sibling child delete first_element_child lang next_element previous= text? write_xml_to
after children description fragment? lang= next_sibling previous_element to_html xml?
ancestors children= do_xinclude get_attribute last_element_child node_name previous_sibling to_s
Nokogiri::XML::Document#methods:
<< canonicalize collect_namespaces create_comment create_entity decorate document encoding errors name remove_namespaces! root= to_java url version
add_child clone create_cdata create_element create_text_node decorators dup encoding= errors= namespaces root slop! to_xml validate
Nokogiri::HTML::Document#methods: fragment meta_encoding meta_encoding= serialize title title= type
instance variables: @decorators @errors @node_cache
[4] pry(#<Kimurai::Base>)> exit
I, [2018-08-22 13:43:47 +0400#26079] [M: 47461994677760] INFO -- : Browser: driver selenium_chrome has been destroyed
$
CLI options:
--engine (optional) engine to use. Default is mechanize--url (optional) url to process. If url omitted, response and url objects inside the console will be nil (use browser object to navigate to any webpage).Kimurai has support for following engines and mostly can switch between them without need to rewrite any code:
:mechanize - pure Ruby fake http browser. Mechanize can’t render javascript and don’t know what DOM is it. It only can parse original HTML code of a page. Because of it, mechanize much faster, takes much less memory and in general much more stable than any real browser. Use mechanize if you can do it, and the website doesn’t use javascript to render any meaningful parts of its structure. Still, because mechanize trying to mimic a real browser, it supports almost all Capybara’s methods to interact with a web page (filling forms, clicking buttons, checkboxes, etc).:poltergeist_phantomjs - PhantomJS headless browser, can render javascript. In general, PhantomJS still faster than Headless Chrome (and Headless Firefox). PhantomJS has memory leakage, but Kimurai has memory control feature so you shouldn’t consider it as a problem. Also, some websites can recognize PhantomJS and block access to them. Like mechanize (and unlike selenium engines) :poltergeist_phantomjs can freely rotate proxies and change headers on the fly (see config section).:selenium_chrome Chrome in headless mode driven by selenium. Modern headless browser solution with proper javascript rendering.:selenium_firefox Firefox in headless mode driven by selenium. Usually takes more memory than other drivers, but sometimes can be useful.Tip: add HEADLESS=false ENV variable before command ($ HEADLESS=false ruby spider.rb) to run browser in normal (not headless) mode and see it’s window (only for selenium-like engines). It works for console command as well.
You can manually create a spider file, or use generator instead:
$ kimurai generate spider simple_spider
require 'kimurai'
class SimpleSpider < Kimurai::Base
@name = "simple_spider"
@engine = :selenium_chrome
@start_urls = ["https://example.com/"]
def parse(response, url:, data: {})
end
end
SimpleSpider.crawl!
Where:
@name name of a spider. You can omit name if use single-file spider@engine engine for a spider@start_urls array of start urls to process one by one inside parse methodparse is the start method, should be always present in spider classresponse, url and datadef parse(response, url:, data: {})
end
response (Nokogiri::HTML::Document object) Contains parsed HTML code of a processed webpageurl (String) url of a processed webpagedata (Hash) uses to pass data between requestsdataImagine that there is a product page which doesn’t contain product category. Category name present only on category page with pagination. This is the case where we can use data to pass category name from parse to parse_product method:
class ProductsSpider < Kimurai::Base
@engine = :selenium_chrome
@start_urls = ["https://example-shop.com/example-product-category"]
def parse(response, url:, data: {})
category_name = response.xpath("//path/to/category/name").text
response.xpath("//path/to/products/urls").each do |product_url|
# Merge category_name with current data hash and pass it next to parse_product method
request_to(:parse_product, url: product_url[:href], data: data.merge(category_name: category_name))
end
# ...
end
def parse_product(response, url:, data: {})
item = {}
# Assign item's category_name from data[:category_name]
item[:category_name] = data[:category_name]
# ...
end
end
You can query response using XPath or CSS selectors. Check Nokogiri tutorials to understand how to work with response:
browser objectFrom any spider instance method there is available browser object, which is Capybara::Session object and uses to process requests and get page response (current_response method). Usually you don’t need to touch it directly, because there is response (see above) which contains page response after it was loaded.
But if you need to interact with a page (like filling form fields, clicking elements, checkboxes, etc) browser is ready for you:
class GoogleSpider < Kimurai::Base
@name = "google_spider"
@engine = :selenium_chrome
@start_urls = ["https://www.google.com/"]
def parse(response, url:, data: {})
browser.fill_in "q", with: "Kimurai web scraping framework"
browser.click_button "Google Search"
# Update response to current response after interaction with a browser
response = browser.current_response
# Collect results
results = response.xpath("//div[@class='g']//h3/a").map do |a|
{ title: a.text, url: a[:href] }
end
# ...
end
end
Check out Capybara cheat sheets where you can see all available methods to interact with browser:
request_to methodFor making requests to a particular method there is request_to. It requires minimum two arguments: :method_name and url:. An optional argument is data: (see above what for is it). Example:
class Spider < Kimurai::Base
@engine = :selenium_chrome
@start_urls = ["https://example.com/"]
def parse(response, url:, data: {})
# Process request to `parse_product` method with `https://example.com/some_product` url:
request_to :parse_product, url: "https://example.com/some_product"
end
def parse_product(response, url:, data: {})
puts "From page https://example.com/some_product !"
end
end
Under the hood request_to simply call #visit (browser.visit(url)) and then required method with arguments:
def request_to(handler, url:, data: {})
request_data = { url: url, data: data }
browser.visit(url)
public_send(handler, browser.current_response, request_data)
end
request_to just makes things simpler, and without it we could do something like:
class Spider < Kimurai::Base
@engine = :selenium_chrome
@start_urls = ["https://example.com/"]
def parse(response, url:, data: {})
url_to_process = "https://example.com/some_product"
browser.visit(url_to_process)
parse_product(browser.current_response, url: url_to_process)
end
def parse_product(response, url:, data: {})
puts "From page https://example.com/some_product !"
end
end
save_to helperSometimes all that you need is to simply save scraped data to a file format, like JSON or CSV. You can use save_to for it:
class ProductsSpider < Kimurai::Base
@engine = :selenium_chrome
@start_urls = ["https://example-shop.com/"]
# ...
def parse_product(response, url:, data: {})
item = {}
item[:title] = response.xpath("//title/path").text
item[:description] = response.xpath("//desc/path").text.squish
item[:price] = response.xpath("//price/path").text[/\d+/]&.to_f
# Add each new item to the `scraped_products.json` file:
save_to "scraped_products.json", item, format: :json
end
end
Supported formats:
:json JSON:pretty_json “pretty” JSON (JSON.pretty_generate):jsonlines JSON Lines:csv CSVNote: save_to requires data (item to save) to be a Hash.
By default save_to add position key to an item hash. You can disable it with position: false: save_to "scraped_products.json", item, format: :json, position: false.
How helper works:
Until spider stops, each new item will be appended to a file. At the next run, helper will clear the content of a file first, and then start again appending items to it.
If you don’t want file to be cleared before each run, add option
append: true:save_to "scraped_products.json", item, format: :json, append: true
It’s pretty common when websites have duplicated pages. For example when an e-commerce shop has the same products in different categories. To skip duplicates, there is simple unique? helper:
class ProductsSpider < Kimurai::Base
@engine = :selenium_chrome
@start_urls = ["https://example-shop.com/"]
def parse(response, url:, data: {})
response.xpath("//categories/path").each do |category|
request_to :parse_category, url: category[:href]
end
end
# Check products for uniqueness using product url inside of parse_category:
def parse_category(response, url:, data: {})
response.xpath("//products/path").each do |product|
# Skip url if it's not unique:
next unless unique?(:product_url, product[:href])
# Otherwise process it:
request_to :parse_product, url: product[:href]
end
end
# Or/and check products for uniqueness using product sku inside of parse_product:
def parse_product(response, url:, data: {})
item = {}
item[:sku] = response.xpath("//product/sku/path").text.strip.upcase
# Don't save product and return from method if there is already saved item with the same sku:
return unless unique?(:sku, item[:sku])
# ...
save_to "results.json", item, format: :json
end
end
unique? helper works pretty simple:
# Check string "http://example.com" in scope `url` for a first time:
unique?(:url, "http://example.com")
# => true
# Try again:
unique?(:url, "http://example.com")
# => false
To check something for uniqueness, you need to provide a scope:
# `product_url` scope
unique?(:product_url, "http://example.com/product_1")
# `id` scope
unique?(:id, 324234232)
# `custom` scope
unique?(:custom, "Lorem Ipsum")
It is possible to automatically skip all already visited urls while calling request_to method, using @config option skip_duplicate_requests: true. With this option, all already visited urls will be automatically skipped. Also check the @config for an additional options of this setting.
storage objectunique? method it’s just an alias for storage#unique?. Storage has several methods:
#all - display storage hash where keys are existing scopes.#include?(scope, value) - return true if value in the scope exists, and false if not#add(scope, value) - add value to the scope#unique?(scope, value) - method already described above, will return false if value in the scope exists, or return true + add value to the scope if value in the scope not exists.#clear! - reset the whole storage by deleting all values from all scopes.It is quite common that some pages of crawling website can return different response code than 200 ok. In such cases, method request_to (or browser.visit) can raise an exception. Kimurai provides skip_request_errors and retry_request_errors config options to handle such errors:
You can automatically skip some of errors while requesting a page using skip_request_errors config option. If raised error matches one of the errors in the list, then this error will be caught, and request will be skipped. It is a good idea to skip errors like NotFound(404), etc.
Format for the option: array where elements are error classes or/and hashes. You can use hash format for more flexibility:
@config = {
skip_request_errors: [{ error: RuntimeError, message: "404 => Net::HTTPNotFound" }]
}
In this case, provided message: will be compared with a full error message using String#include?. Also you can use regex instead: { error: RuntimeError, message: /404|403/ }.
You can automatically retry some of errors with a few attempts while requesting a page using retry_request_errors config option. If raised error matches one of the errors in the list, then this error will be caught and the request will be processed again within a delay.
There are 3 attempts: first: delay 15 sec, second: delay 30 sec, third: delay 45 sec. If after 3 attempts there is still an exception, then the exception will be raised. It is a good idea to try to retry errros like ReadTimeout, HTTPBadGateway, etc.
Format for the option: same like for skip_request_errors option.
If you would like to skip (not raise) error after all retries gone, you can specify skip_on_failure: true option:
@config = {
retry_request_errors: [{ error: RuntimeError, skip_on_failure: true }]
}
It is possible to save custom messages to the run_info hash using add_event('Some message') method. This feature helps you to keep track on important things which happened during crawling without checking the whole spider log (in case if you’re logging these messages using logger). Example:
def parse_product(response, url:, data: {})
unless response.at_xpath("//path/to/add_to_card_button")
add_event("Product is sold") and return
end
# ...
end
...
I, [2018-11-28 22:20:19 +0400#7402] [M: 47156576560640] INFO -- example_spider: Spider: new event (scope: custom): Product is sold
...
I, [2018-11-28 22:20:19 +0400#7402] [M: 47156576560640] INFO -- example_spider: Spider: stopped: {:events=>{:custom=>{"Product is sold"=>1}}}
open_spider and close_spider callbacksYou can define .open_spider and .close_spider callbacks (class methods) to perform some action before spider started or after spider has been stopped:
require 'kimurai'
class ExampleSpider < Kimurai::Base
@name = "example_spider"
@engine = :selenium_chrome
@start_urls = ["https://example.com/"]
def self.open_spider
logger.info "> Starting..."
end
def self.close_spider
logger.info "> Stopped!"
end
def parse(response, url:, data: {})
logger.info "> Scraping..."
end
end
ExampleSpider.crawl!
I, [2018-08-22 14:26:32 +0400#6001] [M: 46996522083840] INFO -- example_spider: Spider: started: example_spider
I, [2018-08-22 14:26:32 +0400#6001] [M: 46996522083840] INFO -- example_spider: > Starting...
D, [2018-08-22 14:26:32 +0400#6001] [M: 46996522083840] DEBUG -- example_spider: BrowserBuilder (selenium_chrome): created browser instance
D, [2018-08-22 14:26:32 +0400#6001] [M: 46996522083840] DEBUG -- example_spider: BrowserBuilder (selenium_chrome): enabled native headless_mode
I, [2018-08-22 14:26:32 +0400#6001] [M: 46996522083840] INFO -- example_spider: Browser: started get request to: https://example.com/
I, [2018-08-22 14:26:34 +0400#6001] [M: 46996522083840] INFO -- example_spider: Browser: finished get request to: https://example.com/
I, [2018-08-22 14:26:34 +0400#6001] [M: 46996522083840] INFO -- example_spider: Info: visits: requests: 1, responses: 1
D, [2018-08-22 14:26:34 +0400#6001] [M: 46996522083840] DEBUG -- example_spider: Browser: driver.current_memory: 82415
I, [2018-08-22 14:26:34 +0400#6001] [M: 46996522083840] INFO -- example_spider: > Scraping...
I, [2018-08-22 14:26:34 +0400#6001] [M: 46996522083840] INFO -- example_spider: Browser: driver selenium_chrome has been destroyed
I, [2018-08-22 14:26:34 +0400#6001] [M: 46996522083840] INFO -- example_spider: > Stopped!
I, [2018-08-22 14:26:34 +0400#6001] [M: 46996522083840] INFO -- example_spider: Spider: stopped: {:spider_name=>"example_spider", :status=>:completed, :environment=>"development", :start_time=>2018-08-22 14:26:32 +0400, :stop_time=>2018-08-22 14:26:34 +0400, :running_time=>"1s", :visits=>{:requests=>1, :responses=>1}, :error=>nil}
Inside open_spider and close_spider class methods there is available run_info method which contains useful information about spider state:
11: def self.open_spider
=> 12: binding.pry
13: end
[1] pry(example_spider)> run_info
=> {
:spider_name=>"example_spider",
:status=>:running,
:environment=>"development",
:start_time=>2018-08-05 23:32:00 +0400,
:stop_time=>nil,
:running_time=>nil,
:visits=>{:requests=>0, :responses=>0},
:error=>nil
}
Inside close_spider, run_info will be updated:
15: def self.close_spider
=> 16: binding.pry
17: end
[1] pry(example_spider)> run_info
=> {
:spider_name=>"example_spider",
:status=>:completed,
:environment=>"development",
:start_time=>2018-08-05 23:32:00 +0400,
:stop_time=>2018-08-05 23:32:06 +0400,
:running_time=>6.214,
:visits=>{:requests=>1, :responses=>1},
:error=>nil
}
run_info[:status] helps to determine if spider was finished successfully or failed (possible values: :completed, :failed):
class ExampleSpider < Kimurai::Base
@name = "example_spider"
@engine = :selenium_chrome
@start_urls = ["https://example.com/"]
def self.close_spider
puts ">>> run info: #{run_info}"
end
def parse(response, url:, data: {})
logger.info "> Scraping..."
# Let's try to strip nil:
nil.strip
end
end
I, [2018-08-22 14:34:24 +0400#8459] [M: 47020523644400] INFO -- example_spider: Spider: started: example_spider
D, [2018-08-22 14:34:25 +0400#8459] [M: 47020523644400] DEBUG -- example_spider: BrowserBuilder (selenium_chrome): created browser instance
D, [2018-08-22 14:34:25 +0400#8459] [M: 47020523644400] DEBUG -- example_spider: BrowserBuilder (selenium_chrome): enabled native headless_mode
I, [2018-08-22 14:34:25 +0400#8459] [M: 47020523644400] INFO -- example_spider: Browser: started get request to: https://example.com/
I, [2018-08-22 14:34:26 +0400#8459] [M: 47020523644400] INFO -- example_spider: Browser: finished get request to: https://example.com/
I, [2018-08-22 14:34:26 +0400#8459] [M: 47020523644400] INFO -- example_spider: Info: visits: requests: 1, responses: 1
D, [2018-08-22 14:34:26 +0400#8459] [M: 47020523644400] DEBUG -- example_spider: Browser: driver.current_memory: 83351
I, [2018-08-22 14:34:26 +0400#8459] [M: 47020523644400] INFO -- example_spider: > Scraping...
I, [2018-08-22 14:34:26 +0400#8459] [M: 47020523644400] INFO -- example_spider: Browser: driver selenium_chrome has been destroyed
>>> run info: {:spider_name=>"example_spider", :status=>:failed, :environment=>"development", :start_time=>2018-08-22 14:34:24 +0400, :stop_time=>2018-08-22 14:34:26 +0400, :running_time=>2.01, :visits=>{:requests=>1, :responses=>1}, :error=>"#<NoMethodError: undefined method `strip' for nil:NilClass>"}
F, [2018-08-22 14:34:26 +0400#8459] [M: 47020523644400] FATAL -- example_spider: Spider: stopped: {:spider_name=>"example_spider", :status=>:failed, :environment=>"development", :start_time=>2018-08-22 14:34:24 +0400, :stop_time=>2018-08-22 14:34:26 +0400, :running_time=>"2s", :visits=>{:requests=>1, :responses=>1}, :error=>"#<NoMethodError: undefined method `strip' for nil:NilClass>"}
Traceback (most recent call last):
6: from example_spider.rb:19:in `<main>'
5: from /home/victor/code/kimurai/lib/kimurai/base.rb:127:in `crawl!'
4: from /home/victor/code/kimurai/lib/kimurai/base.rb:127:in `each'
3: from /home/victor/code/kimurai/lib/kimurai/base.rb:128:in `block in crawl!'
2: from /home/victor/code/kimurai/lib/kimurai/base.rb:185:in `request_to'
1: from /home/victor/code/kimurai/lib/kimurai/base.rb:185:in `public_send'
example_spider.rb:15:in `parse': undefined method `strip' for nil:NilClass (NoMethodError)
Usage example: if spider finished successfully, send JSON file with scraped items to a remote FTP location, otherwise (if spider failed), skip incompleted results and send email/notification to slack about it:
Also you can use additional methods completed? or failed?
class Spider < Kimurai::Base
@engine = :selenium_chrome
@start_urls = ["https://example.com/"]
def self.close_spider
if completed?
send_file_to_ftp("results.json")
else
send_error_notification(run_info[:error])
end
end
def self.send_file_to_ftp(file_path)
# ...
end
def self.send_error_notification(error)
# ...
end
# ...
def parse_item(response, url:, data: {})
item = {}
# ...
save_to "results.json", item, format: :json
end
end
KIMURAI_ENVKimurai has environments, default is development. To provide custom environment pass KIMURAI_ENV ENV variable before command: $ KIMURAI_ENV=production ruby spider.rb. To access current environment there is Kimurai.env method.
Usage example:
class Spider < Kimurai::Base
@engine = :selenium_chrome
@start_urls = ["https://example.com/"]
def self.close_spider
if failed? && Kimurai.env == "production"
send_error_notification(run_info[:error])
else
# Do nothing
end
end
# ...
end
in_parallelKimurai can process web pages concurrently in one single line: in_parallel(:parse_product, urls, threads: 3), where :parse_product is a method to process, urls is array of urls to crawl and threads: is a number of threads:
# amazon_spider.rb
require 'kimurai'
class AmazonSpider < Kimurai::Base
@name = "amazon_spider"
@engine = :mechanize
@start_urls = ["https://www.amazon.com/"]
def parse(response, url:, data: {})
browser.fill_in "field-keywords", with: "Web Scraping Books"
browser.click_on "Go"
# Walk through pagination and collect products urls:
urls = []
loop do
response = browser.current_response
response.xpath("//li//a[contains(@class, 's-access-detail-page')]").each do |a|
urls << a[:href].sub(/ref=.+/, "")
end
browser.find(:xpath, "//a[@id='pagnNextLink']", wait: 1).click rescue break
end
# Process all collected urls concurrently within 3 threads:
in_parallel(:parse_book_page, urls, threads: 3)
end
def parse_book_page(response, url:, data: {})
item = {}
item[:title] = response.xpath("//h1/span[@id]").text.squish
item[:url] = url
item[:price] = response.xpath("(//span[contains(@class, 'a-color-price')])[1]").text.squish.presence
item[:publisher] = response.xpath("//h2[text()='Product details']/following::b[text()='Publisher:']/following-sibling::text()[1]").text.squish.presence
save_to "books.json", item, format: :pretty_json
end
end
AmazonSpider.crawl!
$ ruby amazon_spider.rbI, [2018-08-22 14:48:37 +0400#13033] [M: 46982297486840] INFO -- amazon_spider: Spider: started: amazon_spider
D, [2018-08-22 14:48:37 +0400#13033] [M: 46982297486840] DEBUG -- amazon_spider: BrowserBuilder (mechanize): created browser instance
I, [2018-08-22 14:48:37 +0400#13033] [M: 46982297486840] INFO -- amazon_spider: Browser: started get request to: https://www.amazon.com/
I, [2018-08-22 14:48:38 +0400#13033] [M: 46982297486840] INFO -- amazon_spider: Browser: finished get request to: https://www.amazon.com/
I, [2018-08-22 14:48:38 +0400#13033] [M: 46982297486840] INFO -- amazon_spider: Info: visits: requests: 1, responses: 1
I, [2018-08-22 14:48:43 +0400#13033] [M: 46982297486840] INFO -- amazon_spider: Spider: in_parallel: starting processing 52 urls within 3 threads
D, [2018-08-22 14:48:43 +0400#13033] [C: 46982320219020] DEBUG -- amazon_spider: BrowserBuilder (mechanize): created browser instance
I, [2018-08-22 14:48:43 +0400#13033] [C: 46982320219020] INFO -- amazon_spider: Browser: started get request to: https://www.amazon.com/Practical-Web-Scraping-Data-Science/dp/1484235819/
D, [2018-08-22 14:48:44 +0400#13033] [C: 46982320189640] DEBUG -- amazon_spider: BrowserBuilder (mechanize): created browser instance
I, [2018-08-22 14:48:44 +0400#13033] [C: 46982320189640] INFO -- amazon_spider: Browser: started get request to: https://www.amazon.com/Python-Web-Scraping-Cookbook-scraping/dp/1787285219/
D, [2018-08-22 14:48:44 +0400#13033] [C: 46982319187320] DEBUG -- amazon_spider: BrowserBuilder (mechanize): created browser instance
I, [2018-08-22 14:48:44 +0400#13033] [C: 46982319187320] INFO -- amazon_spider: Browser: started get request to: https://www.amazon.com/Scraping-Python-Community-Experience-Distilled/dp/1782164367/
I, [2018-08-22 14:48:45 +0400#13033] [C: 46982320219020] INFO -- amazon_spider: Browser: finished get request to: https://www.amazon.com/Practical-Web-Scraping-Data-Science/dp/1484235819/
I, [2018-08-22 14:48:45 +0400#13033] [C: 46982320219020] INFO -- amazon_spider: Info: visits: requests: 4, responses: 2
I, [2018-08-22 14:48:45 +0400#13033] [C: 46982320219020] INFO -- amazon_spider: Browser: started get request to: https://www.amazon.com/Web-Scraping-Python-Collecting-Modern/dp/1491910291/
I, [2018-08-22 14:48:46 +0400#13033] [C: 46982320189640] INFO -- amazon_spider: Browser: finished get request to: https://www.amazon.com/Python-Web-Scraping-Cookbook-scraping/dp/1787285219/
I, [2018-08-22 14:48:46 +0400#13033] [C: 46982320189640] INFO -- amazon_spider: Info: visits: requests: 5, responses: 3
I, [2018-08-22 14:48:46 +0400#13033] [C: 46982320189640] INFO -- amazon_spider: Browser: started get request to: https://www.amazon.com/Web-Scraping-Python-Collecting-Modern/dp/1491985577/
I, [2018-08-22 14:48:46 +0400#13033] [C: 46982319187320] INFO -- amazon_spider: Browser: finished get request to: https://www.amazon.com/Scraping-Python-Community-Experience-Distilled/dp/1782164367/
I, [2018-08-22 14:48:46 +0400#13033] [C: 46982319187320] INFO -- amazon_spider: Info: visits: requests: 6, responses: 4
I, [2018-08-22 14:48:46 +0400#13033] [C: 46982319187320] INFO -- amazon_spider: Browser: started get request to: https://www.amazon.com/Web-Scraping-Excel-Effective-Scrapes-ebook/dp/B01CMMJGZ8/
...
I, [2018-08-22 14:49:10 +0400#13033] [C: 46982320219020] INFO -- amazon_spider: Info: visits: requests: 51, responses: 49
I, [2018-08-22 14:49:10 +0400#13033] [C: 46982320219020] INFO -- amazon_spider: Browser: driver mechanize has been destroyed
I, [2018-08-22 14:49:11 +0400#13033] [C: 46982320189640] INFO -- amazon_spider: Browser: finished get request to: https://www.amazon.com/Scraping-Ice-Life-Bill-Rayburn-ebook/dp/B00C0NF1L8/
I, [2018-08-22 14:49:11 +0400#13033] [C: 46982320189640] INFO -- amazon_spider: Info: visits: requests: 51, responses: 50
I, [2018-08-22 14:49:11 +0400#13033] [C: 46982320189640] INFO -- amazon_spider: Browser: started get request to: https://www.amazon.com/Instant-Scraping-Jacob-Ward-2013-07-26/dp/B01FJ1G3G4/
I, [2018-08-22 14:49:11 +0400#13033] [C: 46982319187320] INFO -- amazon_spider: Browser: finished get request to: https://www.amazon.com/Php-architects-Guide-Scraping-Author/dp/B010DTKYY4/
I, [2018-08-22 14:49:11 +0400#13033] [C: 46982319187320] INFO -- amazon_spider: Info: visits: requests: 52, responses: 51
I, [2018-08-22 14:49:11 +0400#13033] [C: 46982319187320] INFO -- amazon_spider: Browser: started get request to: https://www.amazon.com/Ship-Tracking-Maritime-Domain-Awareness/dp/B001J5MTOK/
I, [2018-08-22 14:49:12 +0400#13033] [C: 46982320189640] INFO -- amazon_spider: Browser: finished get request to: https://www.amazon.com/Instant-Scraping-Jacob-Ward-2013-07-26/dp/B01FJ1G3G4/
I, [2018-08-22 14:49:12 +0400#13033] [C: 46982320189640] INFO -- amazon_spider: Info: visits: requests: 53, responses: 52
I, [2018-08-22 14:49:12 +0400#13033] [C: 46982320189640] INFO -- amazon_spider: Browser: driver mechanize has been destroyed
I, [2018-08-22 14:49:12 +0400#13033] [C: 46982319187320] INFO -- amazon_spider: Browser: finished get request to: https://www.amazon.com/Ship-Tracking-Maritime-Domain-Awareness/dp/B001J5MTOK/
I, [2018-08-22 14:49:12 +0400#13033] [C: 46982319187320] INFO -- amazon_spider: Info: visits: requests: 53, responses: 53
I, [2018-08-22 14:49:12 +0400#13033] [C: 46982319187320] INFO -- amazon_spider: Browser: driver mechanize has been destroyed
I, [2018-08-22 14:49:12 +0400#13033] [M: 46982297486840] INFO -- amazon_spider: Spider: in_parallel: stopped processing 52 urls within 3 threads, total time: 29s
I, [2018-08-22 14:49:12 +0400#13033] [M: 46982297486840] INFO -- amazon_spider: Browser: driver mechanize has been destroyed
I, [2018-08-22 14:49:12 +0400#13033] [M: 46982297486840] INFO -- amazon_spider: Spider: stopped: {:spider_name=>"amazon_spider", :status=>:completed, :environment=>"development", :start_time=>2018-08-22 14:48:37 +0400, :stop_time=>2018-08-22 14:49:12 +0400, :running_time=>"35s", :visits=>{:requests=>53, :responses=>53}, :error=>nil}
[
{
"title": "Web Scraping with Python: Collecting More Data from the Modern Web2nd Edition",
"url": "https://www.amazon.com/Web-Scraping-Python-Collecting-Modern/dp/1491985577/",
"price": "$26.94",
"publisher": "O'Reilly Media; 2 edition (April 14, 2018)",
"position": 1
},
{
"title": "Python Web Scraping Cookbook: Over 90 proven recipes to get you scraping with Python, micro services, Docker and AWS",
"url": "https://www.amazon.com/Python-Web-Scraping-Cookbook-scraping/dp/1787285219/",
"price": "$39.99",
"publisher": "Packt Publishing - ebooks Account (February 9, 2018)",
"position": 2
},
{
"title": "Web Scraping with Python: Collecting Data from the Modern Web1st Edition",
"url": "https://www.amazon.com/Web-Scraping-Python-Collecting-Modern/dp/1491910291/",
"price": "$15.75",
"publisher": "O'Reilly Media; 1 edition (July 24, 2015)",
"position": 3
},
...
{
"title": "Instant Web Scraping with Java by Ryan Mitchell (2013-08-26)",
"url": "https://www.amazon.com/Instant-Scraping-Java-Mitchell-2013-08-26/dp/B01FEM76X2/",
"price": "$35.82",
"publisher": "Packt Publishing (2013-08-26) (1896)",
"position": 52
}
]
Note that save_to and unique? helpers are thread-safe (protected by Mutex) and can be freely used inside threads.
in_parallel can take additional options:
data: pass with urls custom data hash: in_parallel(:method, urls, threads: 3, data: { category: "Scraping" })delay: set delay between requests: in_parallel(:method, urls, threads: 3, delay: 2). Delay can be Integer, Float or Range (2..5). In case of a Range, delay number will be chosen randomly for each request: rand (2..5) # => 3engine: set custom engine than a default one: in_parallel(:method, urls, threads: 3, engine: :poltergeist_phantomjs)config: pass custom options to config (see config section)You can use all the power of familiar Rails core-ext methods for scraping inside Kimurai. Especially take a look at squish, truncate_words, titleize, remove, present? and presence.
$ kimurai generate schedule.schedule.rb### Settings ###
require 'tzinfo'
# Export current PATH to the cron
env :PATH, ENV["PATH"]
# Use 24 hour format when using `at:` option
set :chronic_options, hours24: true
# Use local_to_utc helper to setup execution time using your local timezone instead
# of server's timezone (which is probably and should be UTC, to check run `$ timedatectl`).
# Also maybe you'll want to set same timezone in kimurai as well (use `Kimurai.configuration.time_zone =` for that),
# to have spiders logs in a specific time zone format.
# Example usage of helper:
# every 1.day, at: local_to_utc("7:00", zone: "Europe/Moscow") do
# crawl "google_spider.com", output: "log/google_spider.com.log"
# end
def local_to_utc(time_string, zone:)
TZInfo::Timezone.get(zone).local_to_utc(Time.parse(time_string))
end
# Note: by default Whenever exports cron commands with :environment == "production".
# Note: Whenever can only append log data to a log file (>>). If you want
# to overwrite (>) log file before each run, pass lambda:
# crawl "google_spider.com", output: -> { "> log/google_spider.com.log 2>&1" }
# Project job types
job_type :crawl, "cd :path && KIMURAI_ENV=:environment bundle exec kimurai crawl :task :output"
job_type :runner, "cd :path && KIMURAI_ENV=:environment bundle exec kimurai runner --jobs :task :output"
# Single file job type
job_type :single, "cd :path && KIMURAI_ENV=:environment ruby :task :output"
# Single with bundle exec
job_type :single_bundle, "cd :path && KIMURAI_ENV=:environment bundle exec ruby :task :output"
### Schedule ###
# Usage (check examples here https://github.com/javan/whenever#example-schedulerb-file):
# every 1.day do
# Example to schedule a single spider in the project:
# crawl "google_spider.com", output: "log/google_spider.com.log"
# Example to schedule all spiders in the project using runner. Each spider will write
# it's own output to the `log/spider_name.log` file (handled by a runner itself).
# Runner output will be written to log/runner.log file.
# Argument number it's a count of concurrent jobs:
# runner 3, output:"log/runner.log"
# Example to schedule single spider (without project):
# single "single_spider.rb", output: "single_spider.log"
# end
### How to set a cron schedule ###
# Run: `$ whenever --update-crontab --load-file config/schedule.rb`.
# If you don't have whenever command, install the gem: `$ gem install whenever`.
### How to cancel a schedule ###
# Run: `$ whenever --clear-crontab --load-file config/schedule.rb`.
schedule.rb following code:every 1.day, at: "7:00" do
single "example_spider.rb", output: "example_spider.log"
end
$ whenever --update-crontab --load-file schedule.rb. Done!You can check Whenever examples here. To cancel schedule, run: $ whenever --clear-crontab --load-file schedule.rb.
You can configure several options using configure block:
Kimurai.configure do |config|
# Default logger has colored mode in development.
# If you would like to disable it, set `colorize_logger` to false.
# config.colorize_logger = false
# Logger level for default logger:
# config.log_level = :info
# Custom logger:
# config.logger = Logger.new(STDOUT)
# Custom time zone (for logs):
# config.time_zone = "UTC"
# config.time_zone = "Europe/Moscow"
# Provide custom chrome binary path (default is any available chrome/chromium in the PATH):
# config.selenium_chrome_path = "/usr/bin/chromium-browser"
# Provide custom selenium chromedriver path (default is "/usr/local/bin/chromedriver"):
# config.chromedriver_path = "~/.local/bin/chromedriver"
end
You can integrate Kimurai spiders (which are just Ruby classes) to an existing Ruby application like Rails or Sinatra, and run them using background jobs (for example). Check the following info to understand the running process of spiders:
.crawl! method.crawl! (class method) performs a full run of a particular spider. This method will return run_info if run was successful, or an exception if something went wrong.
class ExampleSpider < Kimurai::Base
@name = "example_spider"
@engine = :mechanize
@start_urls = ["https://example.com/"]
def parse(response, url:, data: {})
title = response.xpath("//title").text.squish
end
end
ExampleSpider.crawl!
# => { :spider_name => "example_spider", :status => :completed, :environment => "development", :start_time => 2018-08-22 18:20:16 +0400, :stop_time => 2018-08-22 18:20:17 +0400, :running_time => 1.216, :visits => { :requests => 1, :responses => 1 }, :items => { :sent => 0, :processed => 0 }, :error => nil }
You can’t .crawl! spider in different thread if it still running (because spider instances store some shared data in the @run_info class variable while crawling):
2.times do |i|
Thread.new { p i, ExampleSpider.crawl! }
end # =>
# 1
# false
# 0
# {:spider_name=>"example_spider", :status=>:completed, :environment=>"development", :start_time=>2018-08-22 18:49:22 +0400, :stop_time=>2018-08-22 18:49:23 +0400, :running_time=>0.801, :visits=>{:requests=>1, :responses=>1}, :items=>{:sent=>0, :processed=>0}, :error=>nil}
So what if you’re don’t care about stats and just want to process request to a particular spider method and get the returning value from this method? Use .parse! instead:
.parse!(:method_name, url:) method.parse! (class method) creates a new spider instance and performs a request to given method with a given url. Value from the method will be returned back:
class ExampleSpider < Kimurai::Base
@name = "example_spider"
@engine = :mechanize
@start_urls = ["https://example.com/"]
def parse(response, url:, data: {})
title = response.xpath("//title").text.squish
end
end
ExampleSpider.parse!(:parse, url: "https://example.com/")
# => "Example Domain"
Like .crawl!, .parse! method takes care of a browser instance and kills it (browser.destroy_driver!) before returning the value. Unlike .crawl!, .parse! method can be called from different threads at the same time:
urls = ["https://www.google.com/", "https://www.reddit.com/", "https://en.wikipedia.org/"]
urls.each do |url|
Thread.new { p ExampleSpider.parse!(:parse, url: url) }
end # =>
# "Google"
# "Wikipedia, the free encyclopedia"
# "reddit: the front page of the internetHotHot"
Keep in mind, that save_to and unique? helpers are not thread-safe while using .parse! method.
Kimurai.list and Kimurai.find_by_name()class GoogleSpider < Kimurai::Base
@name = "google_spider"
end
class RedditSpider < Kimurai::Base
@name = "reddit_spider"
end
class WikipediaSpider < Kimurai::Base
@name = "wikipedia_spider"
end
# To get the list of all available spider classes:
Kimurai.list
# => {"google_spider"=>GoogleSpider, "reddit_spider"=>RedditSpider, "wikipedia_spider"=>WikipediaSpider}
# To find a particular spider class by it's name:
Kimurai.find_by_name("reddit_spider")
# => RedditSpider
EXPERIMENTAL
You can automatically setup required environment for Kimurai on the remote server (currently there is only Ubuntu Server 18.04 support) using $ kimurai setup command. setup will perform installation of: latest Ruby with Rbenv, browsers with webdrivers and in additional databases clients (only clients) for MySQL, Postgres and MongoDB (so you can connect to a remote database from ruby).
To perform remote server setup, Ansible is required on the desktop machine (to install: Ubuntu:
$ sudo apt install ansible, Mac OS X:$ brew install ansible)
It’s recommended to use regular user to setup the server, not
root. To create a new user, login to the server$ ssh root@your_server_ip, type$ adduser usernameto create a user, and$ gpasswd -a username sudoto add new user to a sudo group.
Example:
$ kimurai setup [email protected] --ask-sudo --ssh-key-path path/to/private_key
CLI options:
--ask-sudo pass this option to ask sudo (user) password for system-wide installation of packages (apt install)--ssh-key-path path/to/private_key authorization on the server using private ssh key. You can omit it if required key already added to keychain on your desktop (Ansible uses SSH agent forwarding)--ask-auth-pass authorization on the server using user password, alternative option to --ssh-key-path.-p port_number custom port for ssh connection (-p 2222)You can check setup playbook here
After successful setup you can deploy a spider to the remote server using $ kimurai deploy command. On each deploy there are performing several tasks: 1) pull repo from a remote origin to ~/repo_name user directory 2) run bundle install 3) Update crontab whenever --update-crontab (to update spider schedule from schedule.rb file).
Before deploy make sure that inside spider directory you have: 1) git repository with remote origin (bitbucket, github, etc.) 2) Gemfile 3) schedule.rb inside subfolder config (config/schedule.rb).
Example:
$ kimurai deploy [email protected] --ssh-key-path path/to/private_key --repo-key-path path/to/repo_private_key
CLI options: same like for setup command (except --ask-sudo), plus
--repo-url provide custom repo url (--repo-url [email protected]:username/repo_name.git), otherwise current origin/master will be taken (output from $ git remote get-url origin)--repo-key-path if git repository is private, authorization is required to pull the code on the remote server. Use this option to provide a private repository SSH key. You can omit it if required key already added to keychain on your desktop (same like with --ssh-key-path option)You can check deploy playbook here
@configUsing @config you can set several options for a spider, like proxy, user-agent, default cookies/headers, delay between requests, browser memory control and so on:
class Spider < Kimurai::Base
USER_AGENTS = ["Chrome", "Firefox", "Safari", "Opera"]
PROXIES = ["2.3.4.5:8080:http:username:password", "3.4.5.6:3128:http", "1.2.3.4:3000:socks5"]
@engine = :poltergeist_phantomjs
@start_urls = ["https://example.com/"]
@config = {
headers: { "custom_header" => "custom_value" },
cookies: [{ name: "cookie_name", value: "cookie_value", domain: ".example.com" }],
user_agent: -> { USER_AGENTS.sample },
proxy: -> { PROXIES.sample },
window_size: [1366, 768],
disable_images: true,
restart_if: {
# Restart browser if provided memory limit (in kilobytes) is exceeded:
memory_limit: 350_000
},
before_request: {
# Change user agent before each request:
change_user_agent: true,
# Change proxy before each request:
change_proxy: true,
# Clear all cookies and set default cookies (if provided) before each request:
clear_and_set_cookies: true,
# Process delay before each request:
delay: 1..3
}
}
def parse(response, url:, data: {})
# ...
end
end
@config options@config = {
# Custom headers, format: hash. Example: { "some header" => "some value", "another header" => "another value" }
# Works only for :mechanize and :poltergeist_phantomjs engines (Selenium doesn't allow to set/get headers)
headers: {},
# Custom User Agent, format: string or lambda.
# Use lambda if you want to rotate user agents before each run:
# user_agent: -> { ARRAY_OF_USER_AGENTS.sample }
# Works for all engines
user_agent: "Mozilla/5.0 Firefox/61.0",
# Custom cookies, format: array of hashes.
# Format for a single cookie: { name: "cookie name", value: "cookie value", domain: ".example.com" }
# Works for all engines
cookies: [],
# Proxy, format: string or lambda. Format of a proxy string: "ip:port:protocol:user:password"
# `protocol` can be http or socks5. User and password are optional.
# Use lambda if you want to rotate proxies before each run:
# proxy: -> { ARRAY_OF_PROXIES.sample }
# Works for all engines, but keep in mind that Selenium drivers doesn't support proxies
# with authorization. Also, Mechanize doesn't support socks5 proxy format (only http)
proxy: "3.4.5.6:3128:http:user:pass",
# If enabled, browser will ignore any https errors. It's handy while using a proxy
# with self-signed SSL cert (for example Crawlera or Mitmproxy)
# Also, it will allow to visit webpages with expires SSL certificate.
# Works for all engines
ignore_ssl_errors: true,
# Custom window size, works for all engines
window_size: [1366, 768],
# Skip images downloading if true, works for all engines
disable_images: true,
# Selenium engines only: headless mode, `:native` or `:virtual_display` (default is :native)
# Although native mode has a better performance, virtual display mode
# sometimes can be useful. For example, some websites can detect (and block)
# headless chrome, so you can use virtual_display mode instead
headless_mode: :native,
# This option tells the browser not to use a proxy for the provided list of domains or IP addresses.
# Format: array of strings. Works only for :selenium_firefox and selenium_chrome
proxy_bypass_list: [],
# Option to provide custom SSL certificate. Works only for :poltergeist_phantomjs and :mechanize
ssl_cert_path: "path/to/ssl_cert",
# Inject some JavaScript code to the browser.
# Format: array of strings, where each string is a path to JS file.
# Works only for poltergeist_phantomjs engine (Selenium doesn't support JS code injection)
extensions: ["lib/code_to_inject.js"],
# Automatically skip duplicated (already visited) urls when using `request_to` method.
# Possible values: `true` or `hash` with options.
# In case of `true`, all visited urls will be added to the storage's scope `:requests_urls`
# and if url already contains in this scope, request will be skipped.
# You can configure this setting by providing additional options as hash:
# `skip_duplicate_requests: { scope: :custom_scope, check_only: true }`, where:
# `scope:` - use custom scope than `:requests_urls`
# `check_only:` - if true, then scope will be only checked for url, url will not
# be added to the scope if scope doesn't contains it.
# works for all drivers
skip_duplicate_requests: true,
# Automatically skip provided errors while requesting a page.
# If raised error matches one of the errors in the list, then this error will be caught,
# and request will be skipped.
# It is a good idea to skip errors like NotFound(404), etc.
# Format: array where elements are error classes or/and hashes. You can use hash format
# for more flexibility: `{ error: "RuntimeError", message: "404 => Net::HTTPNotFound" }`.
# Provided `message:` will be compared with a full error message using `String#include?`. Also
# you can use regex instead: `{ error: "RuntimeError", message: /404|403/ }`.
skip_request_errors: [{ error: RuntimeError, message: "404 => Net::HTTPNotFound" }],
# Automatically retry provided errors with a few attempts while requesting a page.
# If raised error matches one of the errors in the list, then this error will be caught
# and the request will be processed again within a delay. There are 3 attempts:
# first: delay 15 sec, second: delay 30 sec, third: delay 45 sec.
# If after 3 attempts there is still an exception, then the exception will be raised.
# It is a good idea to try to retry errros like `ReadTimeout`, `HTTPBadGateway`, etc.
# Format: same like for `skip_request_errors` option.
retry_request_errors: [Net::ReadTimeout],
# Handle page encoding while parsing html response using Nokogiri. There are two modes:
# Auto (`:auto`) (try to fetch correct encoding from <meta http-equiv="Content-Type"> or <meta charset> tags)
# Set required encoding manually, example: `encoding: "GB2312"` (Set required encoding manually)
# Default this option is unset.
encoding: nil,
# Restart browser if one of the options is true:
restart_if: {
# Restart browser if provided memory limit (in kilobytes) is exceeded (works for all engines)
memory_limit: 350_000,
# Restart browser if provided requests limit is exceeded (works for all engines)
requests_limit: 100
},
# Perform several actions before each request:
before_request: {
# Change proxy before each request. The `proxy:` option above should be presented
# and has lambda format. Works only for poltergeist and mechanize engines
# (Selenium doesn't support proxy rotation).
change_proxy: true,
# Change user agent before each request. The `user_agent:` option above should be presented
# and has lambda format. Works only for poltergeist and mechanize engines
# (selenium doesn't support to get/set headers).
change_user_agent: true,
# Clear all cookies before each request, works for all engines
clear_cookies: true,
# If you want to clear all cookies + set custom cookies (`cookies:` option above should be presented)
# use this option instead (works for all engines)
clear_and_set_cookies: true,
# Global option to set delay between requests.
# Delay can be `Integer`, `Float` or `Range` (`2..5`). In case of a range,
# delay number will be chosen randomly for each request: `rand (2..5) # => 3`
delay: 1..3
}
}
As you can see, most of the options are universal for any engine.
@config settings inheritanceSettings can be inherited:
class ApplicationSpider < Kimurai::Base
@engine = :poltergeist_phantomjs
@config = {
user_agent: "Firefox",
disable_images: true,
restart_if: { memory_limit: 350_000 },
before_request: { delay: 1..2 }
}
end
class CustomSpider < ApplicationSpider
@name = "custom_spider"
@start_urls = ["https://example.com/"]
@config = {
before_request: { delay: 4..6 }
}
def parse(response, url:, data: {})
# ...
end
end
Here, @config of CustomSpider will be deep merged with ApplicationSpider config, so CustomSpider will keep all inherited options with only delay updated.
Kimurai can work in project mode (Like Scrapy). To generate a new project, run: $ kimurai generate project web_spiders (where web_spiders is a name of project).
Structure of the project:
.
├── config/
│ ├── initializers/
│ ├── application.rb
│ ├── automation.yml
│ ├── boot.rb
│ └── schedule.rb
├── spiders/
│ └── application_spider.rb
├── db/
├── helpers/
│ └── application_helper.rb
├── lib/
├── log/
├── pipelines/
│ ├── validator.rb
│ └── saver.rb
├── tmp/
├── .env
├── Gemfile
├── Gemfile.lock
└── README.md
config/ folder for configutation files
config/initializers Rails-like initializers to load custom code at start of frameworkconfig/application.rb configuration settings for Kimurai (Kimurai.configure do block)config/automation.yml specify some settings for setup and deployconfig/boot.rb loads framework and projectconfig/schedule.rb Cron schedule for spidersspiders/ folder for spiders
spiders/application_spider.rb Base parent class for all spidersdb/ store here all database files (sqlite, json, csv, etc.)helpers/ Rails-like helpers for spiders
helpers/application_helper.rb all methods inside ApplicationHelper module will be available for all spiderslib/ put here custom Ruby codelog/ folder for logspipelines/ folder for Scrapy-like pipelines. One file = one pipeline
pipelines/validator.rb example pipeline to validate itempipelines/saver.rb example pipeline to save itemtmp/ folder for temp. files.env file to store ENV variables for project and load them using DotenvGemfile dependency fileReadme.md example project readmeTo generate a new spider in the project, run:
$ kimurai generate spider example_spider
create spiders/example_spider.rb
Command will generate a new spider class inherited from ApplicationSpider:
class ExampleSpider < ApplicationSpider
@name = "example_spider"
@start_urls = []
@config = {}
def parse(response, url:, data: {})
end
end
To run a particular spider in the project, run: $ bundle exec kimurai crawl example_spider. Don’t forget to add bundle exec before command to load required environment.
To list all project spiders, run: $ bundle exec kimurai list
For project spiders you can use $ kimurai parse command which helps to debug spiders:
$ bundle exec kimurai parse example_spider parse_product --url https://example-shop.com/product-1
where example_spider is a spider to run, parse_product is a spider method to process and --url is url to open inside processing method.
send_item methodYou can use item pipelines to organize and store in one place item processing logic for all project spiders (also check Scrapy description of pipelines).
Imagine if you have three spiders where each of them crawls different e-commerce shop and saves only shoe positions. For each spider, you want to save items only with “shoe” category, unique sku, valid title/price and with existing images. To avoid code duplication between spiders, use pipelines:
pipelines/validator.rb
class Validator < Kimurai::Pipeline
def process_item(item, options: {})
# Here you can validate item and raise `DropItemError`
# if one of the validations failed. Examples:
# Drop item if it's category is not "shoe":
if item[:category] != "shoe"
raise DropItemError, "Wrong item category"
end
# Check item sku for uniqueness using buit-in unique? helper:
unless unique?(:sku, item[:sku])
raise DropItemError, "Item sku is not unique"
end
# Drop item if title length shorter than 5 symbols:
if item[:title].size < 5
raise DropItemError, "Item title is short"
end
# Drop item if price is not present
unless item[:price].present?
raise DropItemError, "item price is not present"
end
# Drop item if it doesn't contains any images:
unless item[:images].present?
raise DropItemError, "Item images are not present"
end
# Pass item to the next pipeline (if it wasn't dropped):
item
end
end
pipelines/saver.rb
class Saver < Kimurai::Pipeline
def process_item(item, options: {})
# Here you can save item to the database, send it to a remote API or
# simply save item to a file format using `save_to` helper:
# To get the name of current spider: `spider.class.name`
save_to "db/#{spider.class.name}.json", item, format: :json
item
end
end
spiders/application_spider.rb
class ApplicationSpider < Kimurai::Base
@engine = :selenium_chrome
# Define pipelines (by order) for all spiders:
@pipelines = [:validator, :saver]
end
spiders/shop_spider_1.rb
class ShopSpiderOne < ApplicationSpider
@name = "shop_spider_1"
@start_urls = ["https://shop-1.com"]
# ...
def parse_product(response, url:, data: {})
# ...
# Send item to pipelines:
send_item item
end
end
spiders/shop_spider_2.rb
class ShopSpiderTwo < ApplicationSpider
@name = "shop_spider_2"
@start_urls = ["https://shop-2.com"]
def parse_product(response, url:, data: {})
# ...
# Send item to pipelines:
send_item item
end
end
spiders/shop_spider_3.rb
class ShopSpiderThree < ApplicationSpider
@name = "shop_spider_3"
@start_urls = ["https://shop-3.com"]
def parse_product(response, url:, data: {})
# ...
# Send item to pipelines:
send_item item
end
end
When you start using pipelines, there are stats for items appears:
pipelines/validator.rb
class Validator < Kimurai::Pipeline
def process_item(item, options: {})
if item[:star_count] < 10
raise DropItemError, "Repository doesn't have enough stars"
end
item
end
end
spiders/github_spider.rb
class GithubSpider < ApplicationSpider
@name = "github_spider"
@engine = :selenium_chrome
@pipelines = [:validator]
@start_urls = ["https://github.com/search?q=Ruby%20Web%20Scraping"]
@config = {
user_agent: "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.84 Safari/537.36",
before_request: { delay: 4..7 }
}
def parse(response, url:, data: {})
response.xpath("//ul[@class='repo-list']/div//h3/a").each do |a|
request_to :parse_repo_page, url: absolute_url(a[:href], base: url)
end
if next_page = response.at_xpath("//a[@class='next_page']")
request_to :parse, url: absolute_url(next_page[:href], base: url)
end
end
def parse_repo_page(response, url:, data: {})
item = {}
item[:owner] = response.xpath("//h1//a[@rel='author']").text
item[:repo_name] = response.xpath("//h1/strong[@itemprop='name']/a").text
item[:repo_url] = url
item[:description] = response.xpath("//span[@itemprop='about']").text.squish
item[:tags] = response.xpath("//div[@id='topics-list-container']/div/a").map { |a| a.text.squish }
item[:watch_count] = response.xpath("//ul[@class='pagehead-actions']/li[contains(., 'Watch')]/a[2]").text.squish.delete(",").to_i
item[:star_count] = response.xpath("//ul[@class='pagehead-actions']/li[contains(., 'Star')]/a[2]").text.squish.delete(",").to_i
item[:fork_count] = response.xpath("//ul[@class='pagehead-actions']/li[contains(., 'Fork')]/a[2]").text.squish.delete(",").to_i
item[:last_commit] = response.xpath("//span[@itemprop='dateModified']/*").text
send_item item
end
end
$ bundle exec kimurai crawl github_spider
I, [2018-08-22 15:56:35 +0400#1358] [M: 47347279209980] INFO -- github_spider: Spider: started: github_spider
D, [2018-08-22 15:56:35 +0400#1358] [M: 47347279209980] DEBUG -- github_spider: BrowserBuilder (selenium_chrome): created browser instance
I, [2018-08-22 15:56:40 +0400#1358] [M: 47347279209980] INFO -- github_spider: Browser: started get request to: https://github.com/search?q=Ruby%20Web%20Scraping
I, [2018-08-22 15:56:44 +0400#1358] [M: 47347279209980] INFO -- github_spider: Browser: finished get request to: https://github.com/search?q=Ruby%20Web%20Scraping
I, [2018-08-22 15:56:44 +0400#1358] [M: 47347279209980] INFO -- github_spider: Info: visits: requests: 1, responses: 1
D, [2018-08-22 15:56:44 +0400#1358] [M: 47347279209980] DEBUG -- github_spider: Browser: driver.current_memory: 116182
D, [2018-08-22 15:56:44 +0400#1358] [M: 47347279209980] DEBUG -- github_spider: Browser: sleep 5 seconds before request...
I, [2018-08-22 15:56:49 +0400#1358] [M: 47347279209980] INFO -- github_spider: Browser: started get request to: https://github.com/lorien/awesome-web-scraping
I, [2018-08-22 15:56:50 +0400#1358] [M: 47347279209980] INFO -- github_spider: Browser: finished get request to: https://github.com/lorien/awesome-web-scraping
I, [2018-08-22 15:56:50 +0400#1358] [M: 47347279209980] INFO -- github_spider: Info: visits: requests: 2, responses: 2
D, [2018-08-22 15:56:50 +0400#1358] [M: 47347279209980] DEBUG -- github_spider: Browser: driver.current_memory: 217432
D, [2018-08-22 15:56:50 +0400#1358] [M: 47347279209980] DEBUG -- github_spider: Pipeline: starting processing item through 1 pipeline...
I, [2018-08-22 15:56:50 +0400#1358] [M: 47347279209980] INFO -- github_spider: Pipeline: processed: {"owner":"lorien","repo_name":"awesome-web-scraping","repo_url":"https://github.com/lorien/awesome-web-scraping","description":"List of libraries, tools and APIs for web scraping and data processing.","tags":["awesome","awesome-list","web-scraping","data-processing","python","javascript","php","ruby"],"watch_count":159,"star_count":2423,"fork_count":358,"last_commit":"4 days ago"}
I, [2018-08-22 15:56:50 +0400#1358] [M: 47347279209980] INFO -- github_spider: Info: items: sent: 1, processed: 1
D, [2018-08-22 15:56:50 +0400#1358] [M: 47347279209980] DEBUG -- github_spider: Browser: sleep 6 seconds before request...
...
I, [2018-08-22 16:11:50 +0400#1358] [M: 47347279209980] INFO -- github_spider: Browser: started get request to: https://github.com/preston/idclight
I, [2018-08-22 16:11:51 +0400#1358] [M: 47347279209980] INFO -- github_spider: Browser: finished get request to: https://github.com/preston/idclight
I, [2018-08-22 16:11:51 +0400#1358] [M: 47347279209980] INFO -- github_spider: Info: visits: requests: 140, responses: 140
D, [2018-08-22 16:11:51 +0400#1358] [M: 47347279209980] DEBUG -- github_spider: Browser: driver.current_memory: 211713
D, [2018-08-22 16:11:51 +0400#1358] [M: 47347279209980] DEBUG -- github_spider: Pipeline: starting processing item through 1 pipeline...
E, [2018-08-22 16:11:51 +0400#1358] [M: 47347279209980] ERROR -- github_spider: Pipeline: dropped: #<Kimurai::Pipeline::DropItemError: Repository doesn't have enough stars>, item: {:owner=>"preston", :repo_name=>"idclight", :repo_url=>"https://github.com/preston/idclight", :description=>"A Ruby gem for accessing the freely available IDClight (IDConverter Light) web service, which convert between different types of gene IDs such as Hugo and Entrez. Queries are screen scraped from http://idclight.bioinfo.cnio.es.", :tags=>[], :watch_count=>6, :star_count=>1, :fork_count=>0, :last_commit=>"on Apr 12, 2012"}
I, [2018-08-22 16:11:51 +0400#1358] [M: 47347279209980] INFO -- github_spider: Info: items: sent: 127, processed: 12
I, [2018-08-22 16:11:51 +0400#1358] [M: 47347279209980] INFO -- github_spider: Browser: driver selenium_chrome has been destroyed
I, [2018-08-22 16:11:51 +0400#1358] [M: 47347279209980] INFO -- github_spider: Spider: stopped: {:spider_name=>"github_spider", :status=>:completed, :environment=>"development", :start_time=>2018-08-22 15:56:35 +0400, :stop_time=>2018-08-22 16:11:51 +0400, :running_time=>"15m, 16s", :visits=>{:requests=>140, :responses=>140}, :items=>{:sent=>127, :processed=>12}, :error=>nil}
Also, you can pass custom options to pipeline from a particular spider if you want to change pipeline behavior for this spider:
spiders/custom_spider.rb
class CustomSpider < ApplicationSpider
@name = "custom_spider"
@start_urls = ["https://example.com"]
@pipelines = [:validator]
# ...
def parse_item(response, url:, data: {})
# ...
# Pass custom option `skip_uniq_checking` for Validator pipeline:
send_item item, validator: { skip_uniq_checking: true }
end
end
pipelines/validator.rb
class Validator < Kimurai::Pipeline
def process_item(item, options: {})
# Do not check item sku for uniqueness if options[:skip_uniq_checking] is true
if options[:skip_uniq_checking] != true
raise DropItemError, "Item sku is not unique" unless unique?(:sku, item[:sku])
end
end
end
You can run project spiders one by one or in parallel using $ kimurai runner command:
$ bundle exec kimurai list
custom_spider
example_spider
github_spider
$ bundle exec kimurai runner -j 3
>>> Runner: started: {:id=>1533727423, :status=>:processing, :start_time=>2018-08-08 15:23:43 +0400, :stop_time=>nil, :environment=>"development", :concurrent_jobs=>3, :spiders=>["custom_spider", "github_spider", "example_spider"]}
> Runner: started spider: custom_spider, index: 0
> Runner: started spider: github_spider, index: 1
> Runner: started spider: example_spider, index: 2
< Runner: stopped spider: custom_spider, index: 0
< Runner: stopped spider: example_spider, index: 2
< Runner: stopped spider: github_spider, index: 1
<<< Runner: stopped: {:id=>1533727423, :status=>:completed, :start_time=>2018-08-08 15:23:43 +0400, :stop_time=>2018-08-08 15:25:11 +0400, :environment=>"development", :concurrent_jobs=>3, :spiders=>["custom_spider", "github_spider", "example_spider"]}
Each spider runs in a separate process. Spiders logs available at log/ folder. Pass -j option to specify how many spiders should be processed at the same time (default is 1).
You can provide additional arguments like --include or --exclude to specify which spiders to run:
# Run only custom_spider and example_spider:
$ bundle exec kimurai runner --include custom_spider example_spider
# Run all except github_spider:
$ bundle exec kimurai runner --exclude github_spider
You can perform custom actions before runner starts and after runner stops using config.runner_at_start_callback and config.runner_at_stop_callback. Check config/application.rb to see example.
Will be updated
The gem is available as open source under the terms of the MIT License.