How to stop/relaunch docker container without losing the changes?

Every time you do a docker run it will spin up a fresh container based on your image. And once a container is started, there are very few things that docker allows you to change with the docker update. So instead, you should preserve your data in an external volume that needs to persist between instances of a container. E.g.

docker run -p 8080:80 -v app-data:/data --name <container_name> <name:tag>

The volume name (app-data) and mount point in the container (/data) can be changed for your own requirements. Then when you destroy and restart a new container, you can mount the same volume in the new container.

what you have to do is build the image from the container you just stopped after making changes. Because your old command still using the old image which doesn't have new changes(you have made changes in container which you just stopped not in image )

docker commit --help

Usage:  docker commit [OPTIONS] CONTAINER [REPOSITORY[:TAG]]

Create a new image from a container's changes

docker commit -a me new_nginx myrepo/nginx:latest then you can start container with the new image you just built

but if you dont want create image with the changes you made(like you dont want to put config containing password in the image) you can use volume mount

docker run -d -P --name web -v /src/webapp:/webapp training/webapp python app.py

This command mounts the host directory, /src/webapp, into the container at /webapp. If the path /webapp already exists inside the container’s image, the /src/webapp mount overlays but does not remove the pre-existing content. Once the mount is removed, the content is accessible again. This is consistent with the expected behavior of the mount command.

Manage data in containers