How to identify docker container?
The docker is one of the famous and most used containerization tools by organizations in order to build, and deploy their applications in various environments.
When you run the docker containers, the system automatically gives a UUID number to each container in order to avoid naming conflicts. In this article, let us understand how to name and rename the docker containers.
The docker container is identified by the following:
Long UUID for example -
5973788c3dcab6b64e9a981b6cfe0d37c60337119af379daf4533ea67c9bc486
Short UUID for example -
5973788c3dca
A name -
competent_germain
NOTE:
You can rename the docker container in two ways.
- Rename a container by the name
- Rename a container by ID
Assign a name to the docker container
In this section let us understand how to name a Docker Container using the --name option with the docker run command.
$ docker run -d --name testubuntu -t ubuntu:test
Output
4b3a8142789cb2621b153a825cf8f64a5fb84ed1c0e58e2549b71d922b7bcb5a
Now let us see the list of docker containers and you can see that the docker container with the name “testubuntu” has been created successfully.
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
4b3a8142789c ubuntu:test "tail -f /dev/null" 38 seconds ago Up 35 seconds testubuntu
Having a name specified to your docker container, it helps the developer use the name directly and perform the docker tasks instead of using the docker container ID.
Example
You can see that the docker operations can be performed using the docker container name
$ docker restart testubuntu $ docker start testubuntu $ docker stop testubuntu
Method-1: Using the docker rename command
In this section let us understand how to rename Docker Container. The Docker provides a command to rename the docker container. You can use this command while the container is in any of the states. However, the running containers may receive the updated name only after it is restarted.
Syntax
docker rename CONTAINER NEW_NAME
Let us check this with an example. Let us rename our ubuntu container using the docker rename command. Firstly, let us check the status of the docker containers
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
5973788c3dca ubuntu "sleep infinity" 19 minutes ago Up 19 minutes competent_germain
Now, let us rename the docker container competent_germain with ubuntu-test using the command mentioned below
$ docker rename competent_germain ubuntu-test
Let us now see the current status of the docker containers using the docker ps command
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
5973788c3dca ubuntu "sleep infinity" 21 minutes ago Up 21 minutes ubuntu-test
Method-2: Using the docker container rename command
You can as well use the other command to rename the docker container. Let us take a look at that in this section.
docker container rename ubuntu-test ubuntu-test-2
Let us now see the current status of the docker containers.
docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
5973788c3dca ubuntu "sleep infinity" 28 minutes ago Up 28 minutes ubuntu-test-2
NOTE:
Method-3: Rename the docker container using container ID
Let us take a look at renaming the docker container using container ID with an example.
Pull and run the hello-world container using the command mentioned below
$ docker pull hello-world
Using default tag: latest
latest: Pulling from library/hello-world
Digest: sha256:faa03e786c97f07ef34423fccceeec2398ec8a5759259f94d99078f264e9d7af
Status: Image is up to date for hello-world:latest
docker.io/library/hello-world:latest
Run the docker using the docker run command
$ docker run hello-world
Output:
Hello from Docker!
This message shows that your installation appears to be working correctly.
To generate this message, Docker took the following steps:
1. The Docker client contacted the Docker daemon.
2. The Docker daemon pulled the "hello-world" image from the Docker Hub.
(amd64)
3. The Docker daemon created a new container from that image which runs the
executable that produces the output you are currently reading.
4. The Docker daemon streamed that output to the Docker client, which sent it
to your terminal.
To try something more ambitious, you can run an Ubuntu container with:
$ docker run -it ubuntu bash
Share images, automate workflows, and more with a free Docker ID:
https://hub.docker.com/
For more examples and ideas, visit:
https://docs.docker.com/get-started/
Now, let us see the status of the docker container
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
859a6afc2e7b hello-world "/hello" 12 seconds ago Exited (0) 10 seconds ago unruffled_kalam
Now let us rename the container using the container ID of the hello-world image.
$ docker rename 859a6afc2e7b testhello
Let us check the status of the docker container. You can see that the container has been renamed to "testhello"
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
859a6afc2e7b hello-world "/hello" About a minute ago Exited (0) About a minute ago testhello
Conclusion
It is essential to name your docker containers so that it's easier to use the name instead of the container ID for troubleshooting purposes. I hope this article helped you understand how to rename the docker containers. For more information please visit the man page of the docker -https://manpages.ubuntu.com/manpages/bionic/man1/docker-container-rename.1.html
In case of any queries please feel free to reach out to us and we will respond at the earliest.
References
https://docs.docker.com/engine/reference/commandline/rename/
https://manpages.ubuntu.com/manpages/bionic/man1/docker-container-rename.1.html
