/Crono

This repo will help you to schedule to restart containers at the same way as crontab, but inside the docker-compose file.

Primary LanguageC#MIT LicenseMIT

Crono

This repo will help you to schedule to restart containers at the same way as crontab, but inside the docker-compose file.

Requirements

A distro Linux, docker, docker-compose, some knowledg about it and Crontab.

Create your docker-compose.yml file.

version: '3'
services:

  service1:
    image: "postgres"
    restart: always
    environment:
      - POSTGRES_USER=postgres
      - POSTGRES_PASSWORD=myStr0ngP4ssw0rd
    labels:
        crono: "* * * * *"

  service2:
    image: "postgres"
    restart: always
    environment:
      - POSTGRES_USER=postgres
      - POSTGRES_PASSWORD=myStr0ngP4ssw0rd
    labels:
        crono: "@hourly"

  service3:
    image: "postgres"
    restart: always
    environment:
      - POSTGRES_USER=postgres
      - POSTGRES_PASSWORD=myStr0ngP4ssw0rd
    labels:
        crono: "5 0 * 8 *"

  service4:
    image: "postgres"
    restart: always
    environment:
      - POSTGRES_USER=postgres
      - POSTGRES_PASSWORD=myStr0ngP4ssw0rd
    labels:
        crono: "50-59 * * * 1-5"

See that inside each service I put a label called 'crono'. This will call to Crono that we want to restart it. The value of this will be the same like Crontab.
For help you, you can see crontab.guru at https://crontab.guru
You can infform some keys like @yearly, @annually, @monthly, @weekly, @daily or @hourly.

Put the Crono service

  crono:
    image: hudsonventura/crono:latest
    restart: always
    volumes:
        - "./docker-compose.yml:/app/docker-compose.yml" # point you docker-compose file
        - "/var/run/docker.sock:/var/run/docker.sock:ro"
    
    environment: 
        - TIMEZONE=America/Sao_Paulo
        - WAIT=3

The first one volume, you have to link your docker-compose file. Crono will read this file to work.

The second one volume, will used from Crono to call Docker Api.

The first one environment, you can identify a timezone. In my tests the default timezone inside container was +0UTC, so I created this.

The second one environment is the time that Crono will wait until all containers be up.
You also can use the docker-compose params called links.

The volumes params are mandatories, but the environments are optional.


The complete example file is in the directory examples.

If you want to compile you image ...


Change docker compose file to get local image:

crono:
    image: crono  #HERE
    restart: always
    volumes:
        - "./docker-compose.yml:/app/docker-compose.yml"
        - "/var/run/docker.sock:/var/run/docker.sock:ro"
    
    environment: 
        - TIMEZONE=America/Sao_Paulo
        - WAIT=3

On example directory, run it to build: 
sudo docker compose down && \
cd .. && \
sudo docker build -t crono -f ./app/Dockerfile_x64_x86/Dockerfile ./app/ && \
cd example/ && \
sudo docker compose up