What Are Docker Image Tags, And How to Use Them?

In simple words, Docker tags convey useful information about a specific image version/variant. They are aliases to the ID of your image which often look like this: f1477ec11d12 . It's just a way of referring to your image. A good analogy is how Git tags refer to a particular commit in your history.

1. How do I run a docker image with a tag?
2. How do I tag in Docker?
3. Does Docker tag create a new image?
4. How does a docker image work?
5. How do I pull an image into Docker?
6. What can I do with Docker image?
7. When should I use Docker tag?
8. Does Docker automatically tag latest?
9. How do I change my Docker image tag?
10. Can two Docker images have the same tag?
11. Does Docker push all tags?
12. Can Docker image have multiple tags?

How do I run a docker image with a tag?

Do the following steps:

1. $ docker images. You will get a list of all local Docker images with the tags specified.
2. $ docker run image_name:tag_name. If you didn't specify tag_name it will automatically run an image with the 'latest' tag. Instead of image_name , you can also specify an image ID (no tag_name).

How do I tag in Docker?

1. Build and tag the image with creack/node:latest. $ ID=$(docker build -q -t creack/node .)
2. Add a new tag $ docker tag $ID creack/node:0.10.24.
3. You can use this and skip the -t part from build $ docker tag $ID creack/node:latest.

Does Docker tag create a new image?

Tags Track Versions of Built Images

Whenever you run a docker build , you create a new image with a unique ID, like “38054d5e8a27.”

How does a docker image work?

Docker Images

Images are the basic building blocks of Docker. You need an image to run a Docker container. Images contain the OS libraries, dependencies, and tools to run an application. Images can be prebuilt with application dependencies for creating containers.

How do I pull an image into Docker?

Pull a repository with multiple images

By default, docker pull pulls a single image from the registry. A repository can contain multiple images. To pull all images from a repository, provide the -a (or --all-tags ) option when using docker pull .

What can I do with Docker image?

A Docker image is a read-only template that contains a set of instructions for creating a container that can run on the Docker platform. It provides a convenient way to package up applications and preconfigured server environments, which you can use for your own private use or share publicly with other Docker users.

When should I use Docker tag?

In simple words, Docker tags convey useful information about a specific image version/variant. They are aliases to the ID of your image which often look like this: f1477ec11d12 . It's just a way of referring to your image. A good analogy is how Git tags refer to a particular commit in your history.

Does Docker automatically tag latest?

If the repository is to be uploaded to the Docker Hub, the repository name must be prefixed with a slash and the Docker Hub user name e.g. amouat/myrepo:mytag. The trick is of course, if you leave the tag part out (e.g. _docker tag myrepo:1.0 myrepo), Docker will automatically give it the tag latest.

How do I change my Docker image tag?

1 Answer

1. For this you could use: docker tag server:latest myname/server:latest.
2. docker tag d583c3ac45fd myname/server:latest.
3. So you can have as many of them associated with the same image as you like. You can remove the old name after you've re-tagged it: docker rmi server.

Can two Docker images have the same tag?

1 Answer. If you have multiple version of the same image, you can tag them with different tags (i.e. xyz/abc-peer:v6, xyz/abc-peer:v7, etc), but you can only have one latest in each repo. If you have two different images, they should be put in different repos.

Does Docker push all tags?

Older Docker clients that do not support --all-tags will push all tags by default (simply omit the option), newer clients will only push latest by default. As an alternative, you may want to push each tag separately. So those will point the same image layer.

Can Docker image have multiple tags?

4 Answers. You can't create tags with Dockerfiles but you can create multiple tags on your images via the command line.