How to change or update Docker image tags

To change the tag of an image in Docker, you can use the docker tag command followed by the image ID and the new tag name. Here are the steps to follow:

1. List the images on your system using the command docker images.

$ docker images

2. Identify the image you want to retag, and take note of its IMAGE ID.

REPOSITORY            TAG       IMAGE ID       CREATED       SIZE
my-image              latest    0d120b6ccaae   3 weeks ago   122MB

3. Use the docker tag command to retag the image. Replace IMAGE_ID with the ID of the image you want to retag and NEW_TAG_NAME with the new tag name you want to assign to the image.

$ docker tag IMAGE_ID NEW_TAG_NAME

4. For example, to retag the image my-image with ID 0d120b6ccaae to my-image:v2, you would run the following command:

$ docker tag 0d120b6ccaae my-image:v2

5. Verify that the tag has been changed by listing the images again.

$ docker images

You should see the image with its new tag listed.