CODEWITHSUNDEEP
dockercentos
quantCode
quantCode

Reputation: 565

Restart container from inside

On a batch job, Am doing a large number of operations inside a docker.

Is there to send a command from inside so docker can come back as if it were just started ?

Upvotes: 16

Views: 25720

Answers (3)

Andy Gee
Andy Gee

Reputation: 3341

This is a nice old unanswered question. Personally I like to drop a file into a directory and have my entry point script detect it to exit the container. This will work as long as the container is set to restart. e.g. restart: unless-stopped

#!/bin/bash
# Begin long running process, add a `&` to do so in the background
/app/scripts/long_running.sh &

# Wait for a signal to restart
while true; do
  if [ -f /app/restart.txt ]; then
    echo "Restarting container..."

    # Remove the restart flag
    rm -f /app/restart.txt

    # Do any additional cleaning up if you need to.

    # exit the container - exit code is optional
    exit 3010
  fi
  sleep 5
done

In your container simply touch /app/restart.txt to trigger a container restart

Upvotes: 4

Max2019
Max2019

Reputation: 118

reboot command works from withing container. I use this in my Go code inside docker

out, err = exec.Command("reboot").Output()

Upvotes: -3

Weike
Weike

Reputation: 1270

You just need to install docker client when building your docker images and map /var/run/docker.sock when running a new container to enable docker client inside the container to connect the docker daemon on the host, then you can use docker command just like on the host.

First, add commands to install docker-ce in your Dockerfile:

FROM centos:7.8.2003

ENV DOCKER_VERSION='19.03.8'

RUN set -ex \
    && DOCKER_FILENAME=https://download.docker.com/linux/static/stable/x86_64/docker-${DOCKER_VERSION}.tgz \
    && curl -L ${DOCKER_FILENAME} | tar -C /usr/bin/ -xzf - --strip-components 1 docker/docker

Then, build a new image and run a new container using it:

$ docker build --tag docker-in-docker:v1 .
$ docker run -dit \
             --name docker-in-docker \
             -v /var/run/docker.sock:/var/run/docker.sock:ro \
             docker-in-docker:v1 bash

Now, you can operate docker-daemon (on the host) inside docker container.

$ docker exec -it docker-in-docker docker ps
CONTAINER ID        IMAGE                 COMMAND                  CREATED             STATUS              PORTS               NAMES
bdc2d81b2227        docker-in-docker:v1   "bash"                   8 seconds ago       Up 7 seconds                            docker-in-docker
# just restart the container docker-in-docker in the container docker-in-docker:
$ docker exec docker-in-docker docker restart docker-in-docker

Upvotes: 14

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