Testcontainers-java: Allow command line arguments for

[codepitbull]

We are currently trying to integrate OpenLDAP into our test suite using the osixia-image (https://github.com/osixia/docker-openldap).
We ran into a problem while creating the container.

There docs show how to get a container going when one needs to load a custom LDIF.

docker run \
  --volume ./bootstrap.ldif:/container/service/slapd/assets/config/bootstrap/ldif/50-bootstrap.ldif \
  osixia/openldap:1.2.2 --copy-service

The tricky part is the --copy-service at the end.
It doesn't look as if there is a way to specify arguments for the command this way in testcontainers.

Is there a reason for this or am I missing something (I hope I didnÖt overlook anything in the docs).

And as a sidenote:
Testcontainers is amazing, we were able to increase the number of intergration tests tremendously thanks to your project!

[bsideup]

Hi @codepitbull!

Thanks for the sidenote! 👍 ☺️

You can do it with .withCmd("--copy-service") :)

[kiview]

@codepitbull Do you think we are lacking docs in this regard?

[codepitbull]

I am sorry, I didn't realize withCmd would extend the existing command. I was under the impression it would replace the command running in the container.
I just figured it out when playing around with it and checking how the resulting command in docker looked like.
That wrong impression came from teh docs here:
https://github.com/testcontainers/testcontainers-java/blob/master/docs/usage/options.md

By default the container will execute whatever command is specified in the image's Dockerfile. To override this, and specify a different command, use withCommand:
This sentence is rather misleading.

[codepitbull]

So my original problem is solved :)

[atomfrede]

Fun fact we thought the same when reading the documentation a few weeks and wanted to raise an issue but then looked at the source. So yes the documentation is very misleading

[kiview]

@codepitbull @atomfrede
Just to be clear, is there a confusion between CMDand ENTRYPOINT?
withCommand should indeed override the specified CMD in the Dockerfile, if I've read the code correctly (haven't tried it out).

And thanks for the sidenote again @codepitbull ❤️

[codepitbull]

Just to make it clear:
withCommand doesn't work as you describe it.
My code does a simple .withCommand("--option") and the --optiongets added to the command, it is not overridden as the documentation suggests.

[kiview]

Which command you are talking about? What is the assumed default CMD of the image to which you are appending your command?

In your initial example, your only command is --copy-service, so you are basically setting it this way, which seems to be expected?

[codepitbull]

The default command of the container is /container/tool/run.

I use the following combination to run the container:

new GenericContainer("osixia/openldap:1.2.1")
              .withExposedPorts(389, 636)
              .withEnv(environment)
              .withCommand("--copy-service")
              .withClasspathResourceMapping(ldif, "/container/service/slapd/assets/config/bootstrap/ldif/custom", BindMode.READ_ONLY);

According to the description I'd expect the container to fail, as I override the command to --copy-service.
Instead I see that the command is expanded to /container/tool/run --copy-service.
That is exactly what I wanted but I didnÖt realize from the description that this would be the outcome :)

[kiview]

You are talking about the Entrypoint here, see https://github.com/osixia/docker-light-baseimage/blob/stable/image/Dockerfile.

When the container is launched, it executes entrypoint + command (this is Docker in general and has nothing to do with Testcontainers).

So I'd say, works as expected 😅

[codepitbull]

Aaaargh, ok.
Thanks for clearing that one up ...
Sorry for the confusion and thanks for teaching me the correct wording in Docker!

Works as expected.

[aguibert]

I'd like to add that I was also confused by the withCommand usage as well.

My scenario is that I wanted to emulate the Docker run command:

docker run \
  -p 8002:9080 \
  rodolpheche/wiremock:2.6.0 \
  --port 9080

Looking at the Dockerfile, I assumed that withCommand would override this line of the Dockerfile:

CMD java $JAVA_OPTS -cp /var/wiremock/lib/*:/var/wiremock/extensions/* com.github.tomakehurst.wiremock.standalone.WireMockServerRunner

which would be very clunky to override/maintain.

I think the subtle difference I missed was the CMD directive of the Dockerfile, and the COMMAND argument for docker run:

$ docker run --help

Usage:  docker run [OPTIONS] IMAGE [COMMAND] [ARG...]

In my case:

• OPTIONS="-p 8002:9080"
• IMAGE="rodolpheche/wiremock:2.6.0"
• COMMAND="--port 9080

So user error in the end, but still confusing due to subtle differences. More of a Docker problem than a Testcontainers problem though

[wlad]

the docs could point out to not confuse the two things 😆