docker-java/docker remote api block until container is finished

Question

I am trying to use the docker remote API from java using docker-java and I'm struggling to find a way to see when the execution of my container has finished:

 CreateContainerResponse container = dockerClient.createContainerCmd("me/vw:v0.1")
                .withVolumes(workingDIR)
                .withBinds(new Bind("/localDrive", workingDIR))
                .withCmd("vw", "/rcv1/rcv1.train.vw.gz", "--cache_file", "/rcv1/cache_train", "-f", "/rcv1/r_temp")
                .withLogConfig(logconf)
                .exec();
        dockerClient.startContainerCmd((container.getId())).exec();

        Thread.sleep(10000); //OBVIOUSLY BROKEN HACK IS BROKEN
        System.out.println("PRINTING LOGS");
        System.out.println(containerLog(container.getId(), dockerClient));

What is the normal way to check if container is finished? Do I have to write something that polls the docker server, or do is there some convenient blocking function/invocation? docker-java has really bad documentation and most of what I've gotten to work is from looking at the test cases.

Cheers,

Nick

What exactly are you trying to do? Why do you want your container to finish? — Matthew, Aug 23 '16 at 08:02
I'm trying to package self contained applications inside a docker image, so that they can be called as if they were local unix programs, but from java. Does this make sense? — XapaJIaMnu, Aug 23 '16 at 09:40
Hmm. I think you need to have your docker client library wait for completiton. [This example](https://github.com/docker-java/docker-java/blob/master/src/test/java/com/github/dockerjava/core/command/AttachContainerCmdImplTest.java) calls `awaitCompletion` which looks promising. — Matthew, Aug 23 '16 at 09:50
Thanks, that looks like what I am looking for. `docker-java` doesn't have the greatest documentation so it will have some time to understand what happens... — XapaJIaMnu, Aug 23 '16 at 09:53

score 6 · Answer 1 · answered Nov 13 '17 at 12:23

6

dockerClient.startContainerCmd(createContainerResponse.getId()).exec();
WaitContainerResultCallback resultCallback = new WaitContainerResultCallback();
dockerClient.waitContainerCmd(createContainerResponse.getId()).exec(resultCallback);
resultCallback.awaitCompletion();
dockerClient.removeContainerCmd(createContainerResponse.getId()).exec();

answered Nov 13 '17 at 12:23

Dmytro Titov

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How to "`awaitCompletion`" in `removeContainerCmd` method? I'm facing this issue: I want to remove a container and wait be removed before starts a new one. Do you know how to do that? – Odravison May 03 '19 at 14:12
Why is it different from another commands? Just await for completion, as in the other cases. – Dmytro Titov May 04 '19 at 07:24

score 0 · Answer 2 · answered Aug 22 '16 at 12:33

0

If you have access to the docker socket you can use the remote API. This is generally only used for admin since it requires full privileges.

answered Aug 22 '16 at 12:33

Matthew

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What exactly in the remote API gives me a blocking read? I am the admin and I have access to the docker socket. – XapaJIaMnu Aug 23 '16 at 07:59
I'm not an expert, but I doubt it has a blocking functionality. You'll have to write that. Though there's probably a python wrapper somewhere. – Matthew Aug 23 '16 at 08:01
Yeah I was asking if there's something available so that I don't have to write it myself. – XapaJIaMnu Aug 23 '16 at 09:40

score 0 · Answer 3 · answered Jun 16 '17 at 13:38

Consider monitoring Docker system events, more here https://docs.docker.com/engine/api/v1.29/#operation/SystemEvents

You will need to create a separate thread and subscribe to the lifecycle of your newly created container. You will get a notification upon your container exit. Notify your main thread and you'll be all right. Laborious.

docker-java/docker remote api block until container is finished

3 Answers3