CODEWITHSUNDEEP
docker
smeeb
smeeb

Reputation: 29537

Does restarting a Docker container "remember" initial run arguments?

I ran a Docker container using a very (8 lines) long list of arguments:

docker run -d -p 5000:5000 --restart=always --name registry \
    -v `pwd`/auth:/auth \
    -e "REGISTRY_AUTH_HTPASSWD_REALM=Registry Realm" \
    -e REGISTRY_AUTH_HTPASSWD_PATH=/auth/htpasswd \
    -v `pwd`/certs:/certs \
    -e REGISTRY_HTTP_TLS_CERTIFICATE=/certs/registry.crt \
    -e REGISTRY_HTTP_TLS_KEY=/certs/registry.key \
    registry:2

I confirmed this was running via docker ps:

CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                    NAMES
ff9c654bfc39        registry:2          "/bin/registry /etc/d"   2 days ago          Up 13 minutes       0.0.0.0:5000->5000/tcp   registry

I then stopped this container via docker stop ff9c654bfc39. I then tried re-running the container by issuing the exact same docker run ... (8 liner) as I did the first time:

Error response from daemon: Conflict. The name "registry" is already in use by container ff9c654bfc39. You have to delete (or rename) that container to be able to reuse that name.

So then I just tried docker restart ff9c654bfc39 and that seemed to work, but I'm not 100% sure Docker "remembered" my 8 lines of arguments from when I initially ran the container. Any ideas as to whether it is remembering? If not, what's the proper restart command to include those 8 lines?

Upvotes: 24

Views: 10905

Answers (1)

Aurélien Thieriot
Aurélien Thieriot

Reputation: 5923

As @gabowsky is explaining in the comments, yes, Docker will remember.

Using start, stop and restart will NOT destroy the container, hence remembering everything, including data (even between reboot of the host). What stop does is to stop the process running inside the container. That's all.

Also, Docker store all the context, variables, etc... in an internal format. You don't have to specify command line arguments again. To see what Docker knows about your container, you can run docker inspect.

On the contrary, rm will destroy everything, including none persisted data, and the container would need to be recreated again (Giving the arguments again this time).

As a final note, you should very much use names instead of SHA1 when referring containers in command line

Upvotes: 29

Related Questions