How to use the command `podman images` (with examples)
Podman is a container engine that allows you to manage containers and container images. The podman images command is used to list and manage Podman images.
Use case 1: List all Podman images
Code:
podman images
Motivation: This use case is useful when you want to see a list of all the Podman images available on your system. It provides an overview of the images that you can use to create containers.
Explanation: The podman images command without any options lists all the Podman images available on the system. This includes the repository, tag, image ID, and creation date/time.
Example output:
REPOSITORY TAG IMAGE ID CREATED SIZE
quay.io/podman/stable latest 8a696b584fa6 2 weeks ago 68.6 MB
docker.io/library/alpine latest 053cde6e8953 4 weeks ago 5.6 MB
Use case 2: List all Podman images including intermediates
Code:
podman images --all
Motivation: This use case is helpful when you need to see all Podman images, including intermediate images. Intermediate images are the layers produced during the build process that are not tagged with a repository and tag.
Explanation: The --all option is used to include all images, including the intermediate images in the output. By default, Podman only shows the topmost images for each repository and tag.
Example output:
REPOSITORY TAG IMAGE ID CREATED SIZE
quay.io/podman/stable latest 8a696b584fa6 2 weeks ago 68.6 MB
<none> <none> 36150b470cc1 2 weeks ago 63.6 MB
<none> <none> 4e76449cac7c 2 weeks ago 68.6 MB
docker.io/library/alpine latest 053cde6e8953 4 weeks ago 5.6 MB
Use case 3: List the output in quiet mode (only numeric IDs)
Code:
podman images --quiet
Motivation: This use case is useful when you only need the numeric IDs of the Podman images for scripting purposes or filtering output.
Explanation: The --quiet option is used for quiet mode, which only displays the numeric IDs of the images. The repository, tag, and other information are not included in the output.
Example output:
8a696b584fa6
36150b470cc1
4e76449cac7c
053cde6e8953
Use case 4: List all Podman images not used by any container
Code:
podman images --filter dangling=true
Motivation: This use case helps in identifying the Podman images that are no longer associated with any container. These “dangling” images can use up valuable disk space and may need to be cleaned up.
Explanation: The --filter dangling=true option filters the list of images to only show the ones that are not being used by any running or stopped containers.
Example output:
REPOSITORY TAG IMAGE ID CREATED SIZE
docker.io/library/alpine latest 053cde6e8953 4 weeks ago 5.6 MB
Use case 5: List images that contain a substring in their name
Code:
podman images "*image|image*"
Motivation: This use case is useful when you want to search for specific images that contain a particular substring in their repository or tag.
Explanation: The argument passed to podman images is a shell glob pattern that filters the images based on their repository or tag names. The asterisk (*) is a wildcard character that allows matching any number of characters, and the vertical bar (|) is a logical OR operator. In this example, the pattern matches images that have either “image” or “image” anywhere in their repository or tag name.
Example output:
REPOSITORY TAG IMAGE ID CREATED SIZE
my-image latest c471ae235ff3 2 weeks ago 27.4 MB
other-image latest f34a84cb586b 3 weeks ago 84.6 MB
another-image latest 9dbdca6084f1 4 weeks ago 33.3 MB
Conclusion:
The podman images command is a versatile tool for managing Podman images. It provides various options to list images, including intermediate images, filter them based on criteria like dangling status, and search images using a substring pattern. Understanding these use cases can help you effectively manage your Podman image repository.
