docker restart container failed: “already in use”, but there's no more docker image

Question

I first got my nginx docker image:

docker pull nginx

Then I started it:

docker run -d -p 80:80 --name webserver nginx
         


        

Answer 1

While the great answers are correct, they didn't actually solve the problem I was facing.

How To:

Safely automate starting of named docker container regardless of its prior state

The solution is to wrap the docker run command with an additional check and either do a run or a stop + run (effectively restart with the new image) based on the result.

This achieves both of my goals:

• Avoids the error
• Allows me to periodically update the image (say new build) and restart safely

#!/bin/bash
# Adapt the following 3 parameters to your specific case
NAME=myname
IMAGE=myimage
RUN_OPTIONS='-d -p 8080:80'

ContainerID="$(docker ps --filter name="$NAME" -q)"

if [[ ! -z "$ContainerID" ]]; then
    echo "$NAME already running as container $ContainerID: stopping ..."
    docker stop "$ContainerID"
fi
echo "Starting $NAME ..."
exec docker run --rm --name "$NAME" $RUN_OPTIONS "$IMAGE"

Now I can run (or stop + start if already running) the $NAME docker container in a idempotent way, without worrying about this possible failure.