bulckan

This project provides a GitOps tool for Docker Compose on a Docker container.

The application clones a GitHub repository, periodically checks for changes to a specific branch and path, and deploys or updates the project using Docker Compose.

At the end of each time interval, in addition to checking for changes and updating the deployment, it re-runs the initial command so that if a service has been removed, it is redeployed while maintaining parity between the deployment on the host and the compose files on Github.

bulckan will show in the logs all the steps to deploy the compose file. It will also store and log the name specified in compose, the last commit that forced the deployment or update on the host, and the number of times it has been updated due to changes on GitHub.

Requirements:

• Docker
• Docker Compose
• Access to a GitHub repository (public or private)

bulckan only monitors changes in the specified path and will only update the configuration of the docker compose file. It does not monitor if the images have been updated, use Watchtower for that by deploying it with bulckan or implement a workflow that changes the image version in the compose when the image is rebuilt.

Note: To test the functionality, it is possible to deploy bulckan as configured. The application points to a branch of the same repository that contains the compose files needed to deploy one or more Apache containers.

Configuration

First, clone this repository and navigate to the project directory:

git clone https://github.com/dockopslab/bulckan.git
cd bulckan

Configure the .env file to access the repository, branch and path where the compose file you want to deploy and maintain with this tool is located:

GITHUB_URL=github.com/dockopslab/bulckan.git
GITHUB_BRANCH=example/bulckan-target
GITHUB_PATH=sample/
CHECK_INTERVAL=60
GITHUB_USERNAME=
GITHUB_TOKEN=

Bulckan deployment:

docker compose up -d

The application will clone the repository and deploy the compose.yml of the specified branch and path:

Starting in 5 seconds...
Cloning repository...
rm: can't remove 'repo': Resource busy
Cloning into 'repo'...
Recording update...
Deploying with docker-compose...
Compose name: 'bulckan-test1'
Last deployed commit: 3ee4dfad909302af3e7561a2877ac1addfc0119d
Total updates: 1
 apache2 Pulling 
 apache1 Pulling 
 efc2b5ad9eec Pulling fs layer 
 fce1785eb819 Pulling fs layer 
 4f4fb700ef54 Pulling fs layer 
 f214daa0692f Pulling fs layer 
 05383fd8b2b3 Pulling fs layer 
 88ad12232aa1 Pulling fs layer 
 f214daa0692f Waiting 
 88ad12232aa1 Waiting 
 05383fd8b2b3 Waiting 
 fce1785eb819 Downloading [==================================================>]     145B/145B
 fce1785eb819 Verifying Checksum 
 fce1785eb819 Download complete 
 4f4fb700ef54 Downloading [==================================================>]      32B/32B
 4f4fb700ef54 Verifying Checksum 
 4f4fb700ef54 Download complete 
 efc2b5ad9eec Downloading [>                                                  ]  294.2kB/29.13MB
 efc2b5ad9eec Downloading
 ..........
 [==================================================>]     291B/291B
 88ad12232aa1 Extracting [==================================================>]     291B/291B
 88ad12232aa1 Pull complete 
 apache1 Pulled 
 Container sample-apache1-1  Creating
 Container sample-apache1-1  Created
 Container sample-apache1-1  Starting
 Container sample-apache1-1  Started
Sleeping for 60 seconds...

By adding the following tags to the target application's compose file, information tags will be set on the containers with the commit that forced the last deployment and the number of updates bulckan has performed to maintain parity:

    labels:
      - "bulckan.deploy.update_count=${UPDATE_COUNT}"
      - "bulckan.deploy.last_commit=${LAST_COMMIT}"

See an example in this compose file.

Multiple deployment configuration

bulckan can be deployed multiple times, so it can point to different repositories and keep different applications updated and deployed at the same time.

If necessary, configure the .git.env file:

GITHUB_USERNAME=
GITHUB_TOKEN=

Configure environment variables in compose.example.yml:

name: 'bulckan-example'

networks:
  bulckan:

volumes:
  repo1:
  repo2:
  repo3:

services:
  bulckan1:
    image: ghcr.io/dockopslab/bulckan:latest
    env_file:
      - .git.env
    environment:
      - GITHUB_URL=github.com/dockopslab/bulckan.git
      - GITHUB_BRANCH=example/bulckan-target
      - GITHUB_PATH=watchtower/
      - CHECK_INTERVAL=3600
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
  
  bulckan2:
    image: ghcr.io/dockopslab/bulckan:latest
    env_file:
      - .git.env
    environment:
      - GITHUB_URL=github.com/dockopslab/bulckan.git
      - GITHUB_BRANCH=example/bulckan-target
      - GITHUB_PATH=sample/
      - CHECK_INTERVAL=120
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock

....

bulckan deployment:

docker-compose -f compose.example.yml up -d

Note: Before deploying multiple docker-compose.yml with Bulckan, it is necessary to check for possible incompatibilities. Errors due to duplication of exposed ports, service names, networks, and others must be corrected before deployment.

Contributions

Contributions are welcome. Please open an issue or send a pull request to improve this project.

License

This project is licensed under the GPL-2.0 license. See the LICENSE file for more details.