html2rss-web

This web application scrapes websites to build and deliver RSS 2.0 feeds.

Features:

• Provides stable URLs for feeds generated by automatic sourcing.
• Create your custom feeds!
• Comes with plenty of included configs out of the box.
• Handles request caching.
• Sets caching-related HTTP headers.

The functionality of scraping websites and building the RSS feeds is provided by the Ruby gem html2rss.

Get started

This application should be used with Docker. It is designed to require as little maintenance as possible. See Versioning and Releases and consider automatic updates.

With Docker

docker run -p 3000:3000 gilcreator/html2rss-web

Then open http://127.0.0.1:3000/ in your browser and click the example feed link.

This is the quickest way to get started. However, it’s also the option with the least flexibility: it doesn’t allow you to use custom feed configs and doesn’t update automatically.

If you want more flexibility and automatic updates sound good to you, read on to get started with docker compose…

With docker compose

Create a docker-compose.yml file and paste the following into it:

services:
  html2rss-web:
    image: gilcreator/html2rss-web
    ports:
      - "3000:3000"
    volumes:
      - type: bind
        source: ./feeds.yml
        target: /app/config/feeds.yml
        read_only: true
    environment:
      RACK_ENV: production
      HEALTH_CHECK_USERNAME: health
      HEALTH_CHECK_PASSWORD: please-set-YOUR-OWN-veeeeeery-l0ng-aNd-h4rd-to-gue55-Passw0rd!
      # AUTO_SOURCE_ENABLED: 'true'
      # AUTO_SOURCE_USERNAME: foobar
      # AUTO_SOURCE_PASSWORD: A-Unique-And-Long-Password-For-Your-Own-Instance
      ## to allow just requests originating from the local host
      # AUTO_SOURCE_ALLOWED_ORIGINS: 127.0.0.1:3000
      ## to allow multiple origins, seperate those via comma:
      # AUTO_SOURCE_ALLOWED_ORIGINS: example.com,h2r.host.tld
  watchtower:
    image: containrrr/watchtower
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
      - "~/.docker/config.json:/config.json"
    command: --cleanup --interval 7200

Start it up with: docker compose up.

If you have not created your feeds.yml yet, download this feeds.yml as a blueprint into the directory containing the docker-compose.yml.

Docker: Automatically keep the html2rss-web image up-to-date

The watchtower service automatically pulls running Docker images and checks for updates. If an update is available, it will automatically start the updated image with the same configuration as the running one. Please read its manual.

The docker-compose.yml above contains a service description for watchtower.

How to use automatic feed generation

[!NOTE]
This feature is disabled by default.

To enable the auto_source feature, comment in the env variables in the docker-compose.yml file from above and change the values accordingly:

environment:
  ## … snip ✁
  AUTO_SOURCE_ENABLED: "true"
  AUTO_SOURCE_USERNAME: foobar
  AUTO_SOURCE_PASSWORD: A-Unique-And-Long-Password-For-Your-Own-Instance
  ## to allow just requests originating from the local host
  AUTO_SOURCE_ALLOWED_ORIGINS: 127.0.0.1:3000
  ## to allow multiple origins, seperate those via comma:
  # AUTO_SOURCE_ALLOWED_ORIGINS: example.com,h2r.host.tld
  ## … snap ✃

Restart the container and open http://127.0.0.1:3000/auto_source/.
When asked, enter your username and password.

Then enter the URL of a website and click on the Generate button.

How to use the included configs

html2rss-web comes with many feed configs out of the box. See the file list of all configs.

To use a config from there, build the URL like this:

lib/html2rss/configs/	domainname.tld/whatever.yml
Would become this URL:
http://localhost:3000/	domainname.tld/whatever.rss
	^^^^^^^^^^^^^^^^^^^^^^^^^^^

How to build your RSS feeds

To build your own RSS feed, you need to create a feed config.
That feed config goes into the file feeds.yml.
Check out the example feed config.

Please refer to html2rss’ README for a description of the feed config and its options. html2rss-web is just a small web application that builds on html2rss.

Versioning and releases

This web application is distributed in a rolling release fashion from the master branch.

For the latest commit passing GitHub CI/CD on the master branch, an updated Docker image will be pushed to Docker Hub: gilcreator/html2rss-web.

GitHub’s @dependabot is enabled for dependency updates and they are automatically merged to the master branch when the CI gives the green light.

If you use Docker, you should update to the latest image automatically by setting up watchtower as described.

Use in production

This app is published on Docker Hub and therefore easy to use with Docker.
The above docker-compose.yml is a good starting point.

If you’re going to host a public instance, please, please, please:

• Put the application behind a reverse proxy.
• Allow outside connections only via HTTPS.
• Have an auto-update strategy (e.g., watchtower).
• Monitor your /health_check.txt endpoint.
• Let the world know and add your instance to the wiki – thank you!

Supported ENV variables

Name	Description
BASE_URL	default: ‘http://localhost:3000’
LOG_LEVEL	default: ‘warn’
HEALTH_CHECK_USERNAME	default: auto-generated on start
HEALTH_CHECK_PASSWORD	default: auto-generated on start
AUTO_SOURCE_ENABLED	default: false
AUTO_SOURCE_USERNAME	no default.
AUTO_SOURCE_PASSWORD	no default.
AUTO_SOURCE_ALLOWED_ORIGINS	no default.
PORT	default: 3000
RACK_ENV	default: ‘development’
RACK_TIMEOUT_SERVICE_TIMEOUT	default: 15
WEB_CONCURRENCY	default: 2
WEB_MAX_THREADS	default: 5
SENTRY_DSN	no default.

Runtime monitoring via GET /health_check.txt

It is recommended to set up monitoring of the /health_check.txt endpoint. With that, you can find out when one of your own configs breaks. The endpoint uses HTTP Basic authentication.

First, set the username and password via these environment variables: HEALTH_CHECK_USERNAME and HEALTH_CHECK_PASSWORD. If these are not set, html2rss-web will generate a new random username and password on each start.

An authenticated GET /health_check.txt request will respond with:

• If the feeds are generatable: success.
• Otherwise: the names of the broken configs.

To get notified when one of your configs breaks, set up monitoring of this endpoint.

UptimeRobot’s free plan is sufficient for basic monitoring (every 5 minutes).
Create a monitor of type Keyword with this information and make it aware of your username and password:

Application Performance Monitoring using Sentry

When you specify SENTRY_DSN in your environment variables, the application will be setup to use Sentry.

Setup for development

Check out the git repository and…

Using Docker

This approach allows you to experiment without installing Ruby on your machine.
All you need to do is install and run Docker.

# Build image from Dockerfile and name/tag it as html2rss-web:
docker build -t html2rss-web -f Dockerfile .

# Run the image and name it html2rss-web-dev:
docker run \
  --detach \
  --mount type=bind,source=$(pwd)/config,target=/app/config \
  --name html2rss-web-dev \
  html2rss-web

# Open an interactive TTY with the shell `sh`:
docker exec -ti html2rss-web-dev sh

# Stop and clean up the container
docker stop html2rss-web-dev
docker rm html2rss-web-dev

# Remove the image
docker rmi html2rss-web

Using installed Ruby

If you’re comfortable with installing Ruby directly on your machine, follow these instructions:

1. Install Ruby >= 3.2
2. gem install bundler foreman
3. bundle
4. foreman start

html2rss-web now listens on port 3000 for requests.

Contribute

Contributions are welcome!

Open a pull request with your changes,
open an issue, or
join discussions on html2rss.