hudsonventura/crono repository overview

⁠Crono

This app will help you schedule container restarts in the same way as crontab, but inside the docker-compose file, together your projects.

⁠Repository

https://github.com/hudsonventura/Crono⁠

⁠About

You can inform a time (like crontab) to restart like this:




It uses less than 1 MB of RAM with 4 containers.

⁠Requirements

A distro Linux, docker, docker-compose, some knowledge 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 (or start if it was down). The value of this will be the same as 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

Functional example 1:

  crono:
    image: hudsonventura/crono:latest
    restart: always
    volumes:
        - "./docker-compose.yml:/app/docker-compose.yml" 
        - "/var/run/docker.sock:/var/run/docker.sock:ro"
        #- "./logs/:/app/logs/" #Optional
    
    environment: 
        #- TZ=America/Sao_Paulo 
        - WAIT=10

The volume - "./docker-compose.yml:/app/docker-compose.yml", you have to point your docker-compose file. Crono will read this file to work.
The volume - "/var/run/docker.sock:/var/run/docker.sock:ro", will used from Crono to call Docker Api.
The volume - "./logs/:/app/logs/", will used to persist logs, if you need.

The environment #- TZ=America/Sao_Paulo, you can identify a timezone. If you ignore, it'll assume Etc/UTC. You can see a complete list in https://en.wikipedia.org/wiki/List_of_tz_database_time_zones⁠

The environment WAIT=10 It'll wait how many seconds you set before read and start the operations on you containers.

⁠If you want to build your Docker image ...

Just:

sudo docker compose up