How to show the run command of a docker container

Question

I use a third party GUI (Synology Docker package) to setup a docker container. However, it\'s limitation makes me need to run the container from the command line. (I want to

Answer 1

So how to reverse engineering docker run command?

There is a github repository which try to reverse engineering docker run command, but it is not perfect currently, version is 0.1.2. You should follow it for updating. Maybe one day you can use it to get correct run command with it.

$ sudo pip install runlike

# run the ubuntu image
$ docker run -ti ubuntu bash

$ docker ps -a  
# suppose you get the container ID 1dfff2ba0226

# Run runlike to get the docker run command. 
$ runlike 1dfff2ba0226
docker run --name=elated_cray -t ubuntu bash

Github repository: runlike

Updates：

Run without installing (Thanks @tilo)

docker run --rm -v /var/run/docker.sock:/var/run/docker.sock \
    assaflavie/runlike YOUR-CONTAINER

or set alias

alias runlike="docker run --rm -v/var/run/docker.sock:/var/run/docker.sock 
 assaflavie/runlike"

runlike YOUR-CONTAINER

Answer 2

I wrote a simple Node-based CLI tool to generate a docker run command from an existing container.

https://www.npmjs.com/package/rekcod

Here's an example:

$ npm i -g rekcod
$ rekcod redis_container

docker run -d --name redis_container --restart always -h a44159e148e1 \
--expose 6379/tcp -e PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin \
-e REDIS_VERSION=3.0.7 -e REDIS_DOWNLOAD_URL=http://download.redis.io/releases/redis-3.0.7.tar.gz \
-e REDIS_DOWNLOAD_SHA1=e56b4b7e033ae8dbf311f9191cf6fdf3ae974d1c \
--entrypoint "/entrypoint.sh" redis "redis-server"

Also handles links and mounted volumes and other stuff.

Not super robust at the moment, but handles more than some of the other things mentioned, and it was more of what I was looking for.

EDIT: In a single command, without installing any software:

docker run --rm -v /var/run/docker.sock:/var/run/docker.sock nexdrew/rekcod redis_container

Answer 3

If you do not want to install anything into your current running Docker server setup, you can simply execute (replace $CONTAINER_NAME with the container name you want to have the run arguments):

docker run -it --rm --volume /var/run/docker.sock:/var/run/docker.sock --privileged docker sh -c "apk add --no-cache nodejs nodejs-npm && npm i -g rekcod && rekcod $CONTAINER_NAME"

(for the rekcod method)

or

docker run -it --rm --volume /var/run/docker.sock:/var/run/docker.sock --privileged docker sh -c "apk add --no-cache py-pip && pip install runlike && runlike $CONTAINER_NAME"

(for the runlike method)

Answer 4

That docker run command isn't specified in the Dockerfile or any other docker-related documents.

Either you find an example in the documentation associated to your container, or you can infer that docker run with (at least for the command and port mapping) a docker ps -a (but that won't give you the possible --volumes-from options)

Check also /usr/syno/etc/packages/Docker-GitLab/config

This differ from the gitlab config itself, which on Synology is available in /usr/syno/etc/packages/Docker/synology_gitlab.config

Answer 5

Use docker inspect:

$ docker inspect foo/bar
[
    {
        # …
        "Config": {
            # …
            "Cmd": [
                "/usr/local/bin/script.sh"
            ],
            # …
        }
    }
]

You can programatically parse this with jq:

$ docker inspect foo/bar | jq -r '.[0]["Config"]["Cmd"][0]'
/usr/local/bin/script.sh