tag a docker image

Docker is a trendy tool that comes with incredible features, one of them being the ability to tag Images. This guide will help you understand a simple method of tagging Docker Images.

Docker Images are the basis of containers. In other terms, an Image is a set of executable software that includes everything needed to run a piece of software, including the code, a runtime, libraries, environment variables, and config files. A tag references a specific image version.

Step 1: Check Existing Docker Images

The first step to tag a Docker Image is to check the list of existing images on your system. Use this simple command in your terminal to illustrate a list of Docker images:

docker images

This command will open a list of images, each with the repository, tag, image ID, creation time, and size.

Step 2: Let’s Create a New Tag

The syntax to create a new tag is:

docker tag SOURCE_IMAGE[:TAG] TARGET_IMAGE[:TAG]

SOURCE_IMAGE[:TAG] is the image that you want to tag. And TARGET_IMAGE[:TAG] is where you’d like to tag the image.

For instance, if you want to tag a Docker image with the ID 7d9495d03763 to “my_image”, the command will look like this:

docker tag 7d9495d03763 my_image

Step 3: Check Newly Tagged Docker Image

After the tagging operation, you can verify whether your new tag is there in the Docker image list. Use the docker images command for this purpose.

docker images

You can now see your newly tagged Docker image in the list with its repository labeled as “my_image” and ‘latest’ in the ‘tag’ section.

In conclusion, you can see how simple it is to tag a Docker image. Tagging Docker images aids in managing versions and rolling back if there are any issues with the latest image. This process is an important best practice for managing Docker images effectively.