uphold

A tool for programmatically verifying database backups

forward3d
595
19
Ruby

Uphold

Schrödinger’s Backup: “The condition of any backup is unknown until a restore is attempted”

So you’re backing up your databases, but are you regularly checking that the backups are actually useable? Uphold will help you automatically test them by downloading the backup, decompressing, loading and then running programmatic tests against it that you define to make sure they really have what you need.

Uphold UI

Table of Contents

Preface

This project is very new and subsequently very beta so contributions and pulls are very much welcomed. We have a TODO file with things that we know about that would be awesome if worked on.

Prerequisites

  • Backups
  • Docker (>= v1.3.*) with the ability to talk to the Docker API

How does it work?

In order to make the processes are repeatable as possible all the code and databases are run inside single process Docker containers. There are currently three types of container, the ui, the tester and the database itself. Each triggers the next…

uphold-ui
 \
  -> uphold-tester
     \
      -> engine-container

This way each time the process is run, the containers are fresh and new, they hold no state. So each time the database is imported into a cold database.

The output of each process run is a log and a state file and these are stored in /var/log/uphold by default. The UI reads these files to display the state of the runs occurring, no other state is stored in the system.

/var/log/uphold
/var/log/uphold/1453489253_my_db_backup.log
/var/log/uphold/1453489253_my_db_backup_ok

This is the output of a backup run for ‘my_db_backup’ that was started at 1453489253 unix epoch time. The log file contains the full output of the run, and the state file is an empty file, it’s name shows the status of the run…

  • ok Backup was declared good, was transported, loaded and tested successfully
  • ok_no_test Backup was successfully transported and loaded into the DB, but there were no tests to run
  • bad_transport Transport failed
  • bad_engine Container did not open it’s port in a timely manner
  • bad_tests At least one of the programmatic tests failed
  • bad An error occurred either in transport or loading into the db engine

Logs are not automatically rotated or removed, it is left up to you to decide how long you want to keep them. Once they become compressed, they will disappear from the UI. The same goes for the exited Docker containers of ‘uphold-tester’, they are left on the system incase you wish to inspect them. The database containers however are wiped after they are used.

Installation

Most of the installation goes around configuring the tool, you must create the following directory structure on the machine you want to run Uphold on…

/etc/uphold/
/etc/uphold/conf.d/
/etc/uphold/engines/
/etc/uphold/transports/
/etc/uphold/tests/
/var/log/uphold

Configuration

Create a global config in /etc/uphold/uphold.yml (even if you leave it empty), the settings inside are…

  • log_level (default: DEBUG)
    • You can decrease the verbosity of the logging by changing this to INFO, but not recommended
  • config_path (default: /etc/uphold)
    • Generally only overridden in development on OSX when you need to mount your own src directory
  • docker_log_path (default: /var/log/uphold)
    • Generally only overridden in development on OSX when you need to mount your own src directory
  • docker_url (default: unix:///var/run/docker.sock)
    • If you connect to Docker via a TCP socket instead of a Unix one, then you would supply tcp://example.com:5422 instead (untested)
  • docker_container (default: forward3d/uphold-tester)
    • If you need to customize the docker container and use a different one, you can override it here
  • docker_tag (default: latest)
    • Can override the Docker container tag if you want to run from a specific version
  • docker_mounts (default: none)
    • If your backups exist on the host machine and you want to use the local transport, the folders they exist in need to be mounted into the container. You can specify them here as a YAML array of directories. They will be mounted at the same location inside the container
  • ui_datetime (default: %F %T %Z)
    • Overrides the strftime used by the UI to display the outcomes, useful if you want to make it smaller or add info

If you change the global config you will need to restart the UI docker container, as some settings are only read at launch time.

uphold.yml Example

log_level: DEBUG
config_path: /etc/uphold
docker_log_path: /var/log/uphold
docker_url: unix:///var/run/docker.sock
docker_container: forward3d/uphold-tester
docker_tag: latest
docker_mounts:
  - /var/my_backups
  - /var/my_other_backups

/etc/uphold/conf.d Example

Each config is in YAML format, and is constructed of a transport, an engine and tests. In your /etc/uphold/conf.d directory simply create as many YAML files as you need, one per backup. Configs in this directory are re-read, so you don’t need to restart the UI container if you add new ones.

enabled: true
name: s3-mongo
engine:
  type: mongodb
  settings:
    timeout: 10
    database: your_db_name
transport:
  type: s3
  settings:
    region: us-west-2
    access_key_id: your-access-key-id
    secret_access_key: your-secret-access-key
    bucket: your-backups
    path: mongodb/systemx/{date}
    filename: mongodb.tar
    date_format: '%Y.%m.%d'
    date_offset: 0
    folder_within: mongodb/databases/MongoDB
tests:
  - test_structure.rb
  - test_data_integrity.rb
  • enabled
    • true or false, allows you to disable a config if needs be
  • name
    • Just so that if it’s referenced anywhere, you have a nicer name

See the sections below for how to configure Engines, Transports and Tests.

Transports

Transports are how you retrieve the backup file itself. They are also responsible for decompressing the file, the code supports nested compression (compressed files within compressed files). Currently implemented transports are…

  • S3
  • Local file

Custom transports can also be loaded at runtime if they are placed in /etc/uphold/transports. If you need extra rubygems installed you will need to create a new Dockerfile with the base set to uphold-tester and then override the Gemfile and re-bundle. Then adjust your uphold.yml to use your new container.

Generic Transport Parameters

Transports all inherit these generic parameters…

  • path
    • This is the path to the folder that the backup is inside, if it contains a date replace it with {date}, eg. /var/backups/2016-01-21 would be /var/backups/{date}
  • filename
    • The filename of the backup file, if it contains a date replace it with {date}, eg. mongodb-2016-01-21.tar would be mongodb-{date}.tar
  • date_format (default: %Y-%m-%d)
    • If your filename or path contains a date, supply it’s format here
  • date_offset (default: 0)
    • When using dates the code starts at Date.today and then subtracts this number, so for checking a backup that exists for yesterday, you would enter 1
  • folder_within
    • Once your backup has been decompressed it may have folders inside, if so, you need to provide where the last directory is, this generally can’t be programmatically found as some database backups may contain folders in their own structure.
S3 (type: s3)

The S3 transport allows you to pull your backup files from a bucket in S3. It has it’s own extra settings…

  • region
    • Provide the region that your S3 bucket resides in (eg. us-west-2)
  • access_key_id
    • AWS access key that has privileges to read from the specified bucket
  • secret_access_key
    • AWS secret access key that has privileges to read from the specified bucket

Paths do not need to be complete with S3, as it provides globbing capability. So if you had a path like this…

my-service-backups/mongodb/2016.01.21.00.36.03/mongodb.tar

Theres no realistic way for us to re-create that date, so you would do this instead…

path: my-service-backups/mongodb/{date}
filename: mongodb.tar
date_format: '%Y.%m.%d'

As the path is sent to the S3 API as a prefix, it will match all folders, the code then picks the first one it matches correctly. So be aware that not being specific enough with the date_format could cause the wrong backup to be tested.

S3 Transport Example
transport:
  type: s3
  settings:
    region: us-west-2
    access_key_id: your-access-key-id
    secret_access_key: your-secret-access-key
    bucket: your-backups
    path: mongodb/systemx/{date}
    filename: mongodb.tar
    date_format: '%Y.%m.%d'
    date_offset: 0
    folder_within: mongodb/databases/MongoDB
Local File (type: local)

The local transport allows you to pull your backup files from the same machine that is running the Docker container. Be aware, since this code runs within a container you will need to add the volume that contains the backup when starting up. We auto-mount /var/uphold to the same place within the container to reduce confusion.

It has no extra parameters and only uses the generic ones, filename, path and folder_within

Local File Example
transport:
  type: local
  settings:
    path: /var/uphold/mongodb
    filename: mongodb.tar
    folder_within: mongodb/databases/MongoDB

Engines

Engines are used to load the backup that was retrieved by the transport into the database. Databases are started inside fresh docker containers each time so no installation is required. Currently supported databases are…

  • MongoDB
  • MySQL
  • PostgreSQL

Custom engines can also be loaded at runtime if they are placed in /etc/uphold/engines

Generic Parameters

Engines all inherit these generic parameters, but are usually significantly easier to configure when compared to transports…

  • type
    • The name of the engine class you want to use (eg. mongodb)
  • database
    • The name of the database you want to recover, as your backup may contain multiple
  • port
    • The port number that the database will run on (engine will provide a sane default)
  • docker_image
    • The name of the Docker container (engine will provide a sane default)
  • docker_tag
    • The tag of the Docker container (engine will provide a sane default)
  • timeout (default: 10)
    • The number of seconds you will give the container to respond on it’s TCP port. You may need to increase this if you start many backup tests at the same time.
MongoDB (type: mongodb)

Unless you need to change any of the defaults, a standard configuration for MongoDB will look quite small.

engine:
  type: mongodb
  settings:
    database: your_db_name
Full mongodb Engine Example
engine:
  type: mongodb
  settings:
    database: your_db_name
    docker_image: mongo
    docker_tag: 3.2.1
    port: 27017
MySQL (type: mysql)
engine:
  type: mysql
  settings:
    database: your_database_name
    sql_file: your_sql_file.sql
Full mysql Engine Example
engine:
  type: mysql
  settings:
    database: your_database_name
    docker_image: mariadb
    docker_tag: 5.5.42
    port: 3306
    sql_file: MySQL.sql
PostgreSQL (type: postgresql)
engine:
  type: postgresql
  settings:
    database: your_database_name
    sql_file: your_sql_file.sql
Full postgresql Engine Example

The database also becomes your username for when you run the tests.

engine:
  type: postgresql
  settings:
    database: your_database_name
    docker_image: postgres
    docker_tag: 9.5.0
    port: 5432
    sql_file: PostgreSQL.sql

Tests

Tests are the final step in configuration. They are how you validate that the data contained within your backup is really what you want, and that your backup is operating correctly. Tests are written in Ruby using Minitest, this gives you the most flexibility in writing tests programmatically as it supports both Unit & Spec tests. To configure a test you simply provide an array of ruby files you want to run…

tests:
  - test_structure.rb
  - test_data_integrity.rb

Tests should be placed within the /etc/uphold/tests directory, all files inside will be volume mounted into the container so if you need extra files they are available to you.

Example Test

We need to establish a connection to the database, and the values will not be known in advance. So they will be provided to you by environmental variables UPHOLD_IP, UPHOLD_PORT and UPHOLD_DB. You must use these when connecting to your database.

require 'minitest/autorun'
require 'mongoid'

class TestClients < Minitest::Test
  Mongo::Logger.logger.level = Logger::FATAL
  @@mongo = Mongo::Client.new("mongodb://#{ENV['UPHOLD_IP']}:#{ENV['UPHOLD_PORT']}/#{ENV['UPHOLD_DB']}")

  def test_that_we_can_talk_to_mongo
    assert_equal 1, @@mongo.collections.count
  end
end

Obviously this is just a simple test, but you can write any number of tests you like. All must pass in order for the backup to be considered ‘good’.

Running

Once you have finished your configuration, to get the system running you only need to start the Docker container called ‘uphold-ui’.

docker pull forward3d/uphold-ui:latest
docker run \
  --rm \
  -p 8079:8079 \
  -v /var/run/docker.sock:/var/run/docker.sock \
  -v /etc/uphold:/etc/uphold \
  -v /var/log/uphold:/var/log/uphold \
  forward3d/uphold-ui:latest
  • You must make sure that you mount in the docker.sock from wherever it resides.
  • Feel free to change the port number if you don’t want it to start up on port 8079.
  • Mount in the config and log directories as otherwise it can’t read your configuration.

Once the container is live you can browse to it, see all previous available runs for a backup and the states the ended in. You can manually start a backup test from here if you want to.

Scheduling

No option to schedule backup runs exists at present. Until one exists you can use the API to trigger backup runs to start. This way you can schedule however you like, crontab, notifier or any other service capable of sending a POST.

API

GET /api/1.0/backups/config-name-here

This will return all the available backup runs for the config name provided in JSON format…

[
  {
    "epoch": 1453921377,
    "state": "ok",
    "filename": "1453921377_s3-mongo.log"
  },
  {
    "epoch": 1453909916,
    "state": "ok",
    "filename": "1453909916_s3-mongo.log"
  }
]

GET /api/1.0/backups/config-name-here/latest

This will return a plain text string of the state of the last backup run for the config name provided. If no runs were available, it will return none

POST /api/1.0/backup

You must pass the name of the config you want to trigger in a form field called name. It will then start the run and return 200. An example of how to trigger a backup run for the config named s3-mongo…

curl --data "name=s3-mongo" http://ip.of.your.container/api/1.0/backup

Development

To aid with development there is a helper script in the root directory called build_and_run and build_and_inspect which will build or inspect the Dockerfile and then run it using some default options. Since otherwise testing is a bit of a nightmare when trying to talk to containers on your local machine. Various folders from within the project directory will be auto-mounted into the container…

  • dev/uphold.yml -> /etc/uphold/uphold.yml
  • dev/conf.d -> /etc/uphold/conf.d
  • dev/tests -> /etc/uphold/tests
  • dev/custom/engines -> /etc/uphold/engines
  • dev/custom/transports -> /etc/uphold/transports
  • dev/blobs -> /var/backups

Remember to place a uphold.yml config of your own in the dev/config directory.