Today, I bring you this tutorial born out of the need to execute Docker commands using the task scheduler Ofelia (https://devcodelight.com/automatizar-tareas-con-cron-desde-docker-con-ofelia)
To execute Docker commands within a container that is running with Docker on a local machine, the first thing we need to do is add a Docker client to our container.
To create the custom image, I use Alpine:
Use a lighter base image (Alpine Linux)
FROM alpine:latest
Install the Docker client
RUN apk --no-cache add docker
Define the default command to run when the container starts
CMD ["/bin/sh", "-c", "sleep infinity"]
And to launch the image, I’ll use this Docker compose:
version: "3"
services:
docker_executor:
build:
context: .
container_name: container_docker
volumes:
- /var/run/docker.sock:/var/run/docker.sock
With this configuration, we can now execute Docker commands in this container. With the following command, you can run ‘docker ps’ and see which containers it has access to:
docker-compose exec container_docker docker ps
Thanks to this setup, I’ve been able to perform my automatic backups (https://devcodelight.com/hacer-una-copia-de-seguridad-de-mysql-o-mariadb-con-ofelia-cron-y-docker)
