We can use docker stop xxx or docker container stop xxx to stop a container, but what's the difference between these? I looked at the official docs, the two commands had the same description and usage format.
Also, what's the parent command meaning in docker? Thanks!
Both are same. Some frequently used commands like docker container stop etc have shortened aliases under docker parent command.
Parent command is just the command one level up. For docker container stop, stop is the subcommand of docker container and docker container is called the parent command.
Related
I use the dotnet3.5 image to run containers on win10 with docker desktop 2.1.0.1(37199). Sadly, I found that after I had created a container, did nothing to it, and left it alone for 4 days, the container automotically became unstoppable. The snapshot tells the story.
The container seemed existing there when docker ps -a, but I cannot get into the container by docker exec. And for I cannot stop it--the docker stop process hangs there after I use docker stop container2--I cannot rm the container.
The only way to resolve this issue is to restore docker desktop's factory setting.
By the way, although in the snapshot the running image is aspnet:3.5-windowsservercore-10.0.14393.953, this issue also happens when the aspnet:3.5
Does anyone have good ideas to the unstoppable container? Any suggestions are welcome.
The command used above is incorrect. There is a difference between the commands and options we use. "# docker ps" or "# docker container ls" will give you the list of currently running processes or active containers.
Whereas "-a" will give you all the list of all those which are used to date which contains the list of active and deleted containers.
In your case, the container was is not there and you are trying to access the one which is non-existing, which is why it is stuck.
I init a docker container as my compile env, now I just want to know how to determine if the entry code is run completely, then I can do another thing...
I'm not really sure if that is what you are asking about but when command pointed in CMD or ENTRYPOINT ends the docker container will stop.
To list running containers use:
docker ps
To list all containers (including stopped) use:
docker ps -a
You can take a look in the container with docker logs.
To use this you should support something in your code to determine that your code run succesfull e.g. for python the logger library (or simpler: print-statements).
Is there a docker command which works like the vagrant up command?
I'd like to use the arangodb docker image and provide a Dockerfile for my team without forcing my teammates to get educated on the details of its operation, it should 'just work'. Within the the project root, I would expect the database to start and stop with a standard docker command. Does this not exist? If so, why not?
Docker Compose could do it.
docker-compose up builds image, creates container and starts it.
docker-compose stop stops the container.
docker-compose start restarts the container.
docker-compose down stops the container and removes image and the container.
With Docker compose file you can configure the ArangoDB (expose ports, volume mapping for db initialisation, etc.). Place the compose file to the project root, and run the up command.
I really enjoy the concept of having a cluster of docker machines available to execute docker services. I also like the additional features not available to singular docker containers (such as docker secret).
But I really have no need for long-standing services. My use case is to simply execute a bash script to use the docker swarm to take in an arbitrary number of finite commands, and execute each as a running docker container on the same docker image, while using the secrets loaded up with docker swarm's secrets.
Can I do this?
I do not want to have this container be "long running". I want it to run, and then exit with the output when the bash script loaded into the container is finished.
You can apply the ideas presented in "One-shot containers on Docker Swarm" from alex ellis.
You still neeeds to create a service, but with the right restart policy.
For instance, for a quick web server:
docker service create --restart-condition=none --name crawler1 -e url=http://blog.alexellis.io -d crawl_site alexellis2/href-counter
(--restart-condition, not --restart-policy, as commented by ethergeist)
So by setting a restart condition of 0, the container will be scheduled somewhere in the swarm as a (task). The container will execute and then when ready - it will exit.
If the container fails to start for a valid reason then the restart policy will mean the application code never executes. It would also be ideal if we could immediately return the exit code (if non-zero) and the accompanying log output, too.
For the last part, use his tool: alexellis/jaas.
Run your first one-shot container:
# jaas -rm -image alexellis2/cows:latest
The -rm flag removes the Swarm service that was used to run your container.
The exit code from your container will also be available, you can check it with echo $?.
I edited a file in a running docker container and restarted it, unfortunately my last edit was not correct. So every time I start the container with:
docker start <containerId>
It always exits immediately.
Now I can not even modify my edit back, since
docker exec -it <containerId> bash
can only run on a running docker.
The question is how can I change it and restart the container now? Or I had to abandon it and start a new container from an existing image?
You didn't supply any details regarding your container's purpose, or what you modified. Conceptually, you could create the file that needs to be modified in a place on your filesystem and mount that file into the container as a volume when you start it, like:
docker run -it -v /Users/<path_to_file>:<container_path_to_file> <container>
Hovever, this is bad form, as your container loses portability at that point without committing a new image.
Ideally, changes that need to be made inside of a Docker container are made in the Dockerfile, and the container image re-built. This way, your initial, working container state is represented in your Dockerfile code, making your configuration repeatable, portable, and immutable.
The file system of exited containers can still be changed. The preferable way is probably:
docker cp <fixedFile> <containerId>:<brokenFile>
But you can also circumvent docker completely; see here.