How to save changes made to a container in Docker?

To preserve the changes made to a container, you can use two main methods provided by Docker: creating an image and using the Docker commit command.

1. Image Creation: You can save modifications made to a container by creating a new image. Firstly, stop and save the container as a snapshot (pausing the container state), then use the `docker commit` command to convert the container snapshot into a new image. Here are the specific steps:

Stop the container: Use the `docker stop` command to halt a running container.

     docker stop <container_id>

Create an image snapshot from a container: Use the `docker commit` command to generate a new image, specifying the container ID and the new image name.

     docker commit <container_id> <new_image_name>

Option:
2. By using the Docker commit command, you can save any modifications made to a container by converting its state into a new image. Here are the specific steps:

Modify containers: Making necessary changes to containers such as installing software packages, configuring files, or modifying files.

Create a new image using the `docker commit` command, specifying the container ID and the new image name.

     docker commit <container_id> <new_image_name>

No matter which method you use, a new image will be created containing the modifications made to the container. You can start a new container by running the new image and apply these modifications.

Please note that the above method only applies to saving changes made within the container and will not save the container’s data volumes (if any). If you want to preserve the data within the container’s data volumes, you may consider using Docker volumes or saving the data to a local directory on the host machine.