I am using rabbitmq docker image https://hub.docker.com/_/rabbitmq I wanted to make changes in rabbitmq.conf file inside container for testing a config, so I tried
rabbitmqctl stop
after making the changes. But this stops the whole docker container. I even tried
rabbitmq-server restart
but that too doesn't work saying ports are in use. How do I restart the service without restarting the whole container?
Normally Docker containers are made so that they live while their main process does. If the application exits normally or otherwise, so does the container.
It is easier to accept this behavior than fight it, you just need to create a config on your host machine and mount it inside the container. After that you can make changes to the local file and restart the container to make the application to read the updated configuration. To do so:
# Copy config from the container to your machine
docker cp <insert container name>:/etc/rabbitmq/rabbitmq.config .
# (optional) make changes to the copied rabbitmq.config
...
# Start a new container with the config mounted inside (substitute /host/path
# with a full path to your local config file)
docker run -v /host/path/rabbitmq.config:/etc/rabbitmq/rabbitmq.config <insert image name here>
# Now local config appears inside the container and so all changes
# are available immediately. You can restart the container to restart the application.
If you prefer the hard way, you can customize the container so that it starts a script (you have to write it) instead of rabbimq. The script has to start server in background and check whether the process is alive. You can find hints how to do that in the "Run multiple services in a container" article.