CODEWITHSUNDEEP
docker
nathan1658
nathan1658

Reputation: 323

Life-cycle difference between docker run and docker start

I have a fundamental question about container life cycle.

For example I run the following command

Create new ubuntu container and run the bash command

docker run -it ubuntu bash

In the container's bash

exit

The new container will be in state EXITED

docker ps -a

Then I use docker start to restart the container

docker start xxxx(container name)
docker exec -it xxxx(container name) /bin/bash

In the restarted container's bash

exit

The restarted container is still running

docker ps -a

May I know the reason behind for this behavior? Thank you!

Upvotes: 0

Views: 78

Answers (1)

Krishna Chaurasia
Krishna Chaurasia

Reputation: 9580

With the docker run command:

docker run -it ubuntu bash

the container is started with the execution of the bash command, so when you exit from the bash, the container also exits as bash is the main process running inside the container.

However with the docker exec command:

docker exec -it xxxx(container name) /bin/bash

the container is already running the command defined by the CMD/ENTRYPOINT and bash is the command executed as a separate process. So, exiting from bash after docker start exits the bash process and the main process is still continued.

Upvotes: 1

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