3 Podman Images

Use Podman to search for, pull, review, and manage images that can be used to start containers and pods.

A container image is a read-only template that's used to generate a container. The image contains all the requirements for a service or application to run. Images can be limited in scope, for example, to host a single service such as a web server application. Or, images can be extensive enough to include a basic OS environment, such as a minimal Oracle Linux release.

Images can be tagged to identify different versions of the same image. Some images might include a default tag called latest so that Podman users can identify the most recent version of the image, but using those in production environments is considered bad practice because they might contain breaking changes or create unexpected variations between software deployments. Oracle Linux images don't provide a latest tag. For more information, see Oracle Linux Container Image Tagging Conventions.

Images are often hosted on container registries that can be accessed over HTTP/S by Podman instances to obtain particular image versions. Registries are described in more detail in Container Registries.

To change an existing image or create custom images, use the Buildah utility. For more information, see Buildah.

Use the podman search command to run a search for container images in container registries that are configured on an Oracle Linux system.

For more information about the podman search command, use the podman-search(1) manual page.

For more information about how to configure container registries for use with Podman, see Container Registries.

Example 3-1 Search container registries for a container image

Search the configured registries for an oraclelinux image: 

podman search oraclelinux

The output looks similar to:

NAME                                          DESCRIPTION
container-registry.oracle.com/os/oraclelinux  Oracle Linux
docker.io/library/oraclelinux                 Official Docker builds of Oracle Linux.
docker.io/amd64/oraclelinux                   Official Docker builds of Oracle Linux.
docker.io/litmusimage/oraclelinux             
docker.io/arm64v8/oraclelinux                 Official Docker builds of Oracle Linux.
...

Pulling Images From a Container Registry

Pull a copy of a container image from a container registry using the podman pull command.

After you find an image, download a copy of it using the podman pull command, specifying the image reference as follows: 

podman pull registry.host/repository/image_name:tag

  • The registry.host domain is the resolvable hostname of the registry where the image is hosted, such as example.com. Although the registry host is often required, if the registry is already listed within the Podman configuration then specifying this value is optional.

  • The repository value is optional and depends on how images are stored on the registry.

  • The image_name value is required to specify which container image to download.

  • The tag represents a version of the image and we recommend that this is specified. Many tools default to using the latest tag if no tag is specified but this can lead to errors and is considered bad practice. See Oracle Linux Container Image Tagging Conventions for more information on tags and why the latest tag is unreliable.

Shortcuts to registries and repositories for some commonly used container image names are stored in /etc/containers/registries.conf.d/000-shortnames.conf. Those shortcuts enable you to pull an image without needing to know the registry or repository to search, for example:

Container images are downloaded into the local container image store. This storage is described in more detail in Podman Storage.

For more information on the podman pull command, use the podman-pull(1) manual page.

Example 3-2 Pull an image from the Oracle Container Registry

Pull a slim Oracle Linux 9 container image from the Oracle Container Registry: 

podman pull container-registry.oracle.com/os/oraclelinux:9-slim

The output looks similar to:

Trying to pull container-registry.oracle.com/os/oraclelinux:9-slim...
Getting image source signatures
Copying blob 60539f6b41ad done   | 
Copying config 46cfa93e02 done   | 
Writing manifest to image destination
46cfa93e021dd2ca65c70112d8d578484c3a9be71d4b05af6c027d4b7ae43182

Because the Oracle Container Registry is configured for use with Podman by default, the previous command could equally be specified as follows:

podman pull os/oraclelinux:9-slim

Example 3-3 Pull an image using a short name

Pull a slim Oracle Linux 9 container image from the Oracle Container Registry using the image short name: 

podman pull oraclelinux:9-slim

Inspecting an Image

After downloading a container image, use the podman inspect command to review the container image metadata and default configuration settings.

For more information on the podman inspect command, use the podman-inspect(1) manual page.

Example 3-4 Inspect a container image

Review the slim Oracle Linux 9 container image: 

podman inspect container-registry.oracle.com/os/oraclelinux:9-slim

The command provides similar JSON output and looks similar to the following:

[
     {
          "Id": "46cfa93e021dd2ca65c70112d8d578484c3a9be71d4b05af6c027d4b7ae43182",
          "Digest": "sha256:58c00a82b6a523256ecbeefc0f4dfdda11c460c1a2b5bf5ec1288fa0bb2fad68",
          "RepoTags": [
               "container-registry.oracle.com/os/oraclelinux:9-slim"
          ],
          "RepoDigests": [
               "container-registry.oracle.com/os/oraclelinux@sha256:58c00a82b6a523256ecbeefc0f4dfdda11c460c1a2b5bf5ec1288fa0bb2fad68",
               "container-registry.oracle.com/os/oraclelinux@sha256:c7ba887b97ed69de05320f5b558c4dc42805194814935fa5ba329e6f6384e06e"
          ],
          "Parent": "",
          "Comment": "",
          "Created": "2025-07-01T21:09:11.79180435Z",
          "Config": {
               "Env": [
                    "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
               ],
               "Cmd": [
                    "/bin/bash"
               ],
               "Labels": {
                    "io.buildah.version": "1.33.11"
               }
          },
          "Version": "",
          "Author": "",
          "Architecture": "amd64",
          "Os": "linux",
          "Size": 116893435,
          "VirtualSize": 116893435,
          "GraphDriver": {
               "Name": "overlay",
               "Data": {
                    "UpperDir": "/home/opc/.local/share/containers/storage/overlay/d62ccb1665e5b7444fa53147fd18e2a7989fff5f330480711e62445a6443ca92/diff",
                    "WorkDir": "/home/opc/.local/share/containers/storage/overlay/d62ccb1665e5b7444fa53147fd18e2a7989fff5f330480711e62445a6443ca92/work"
               }
          },
          "RootFS": {
               "Type": "layers",
               "Layers": [
                    "sha256:d62ccb1665e5b7444fa53147fd18e2a7989fff5f330480711e62445a6443ca92"
               ]
          },
          "Labels": {
               "io.buildah.version": "1.33.11"
          },
          "Annotations": {},
          "ManifestType": "application/vnd.docker.distribution.manifest.v2+json",
          "User": "",
          "History": [
               {
                    "created": "2025-07-01T21:09:10.947182529Z",
                    "created_by": "/bin/sh -c #(nop) ADD file:6bff5a6139bdf95b00802c939bfcb5e9b8c2324a854e6124b95d3312f3428158 in / "
               },
               {
                    "created": "2025-07-01T21:09:11.791909449Z",
                    "created_by": "/bin/sh -c #(nop) CMD [\"/bin/bash\"]",
                    "comment": "FROM 45b3741d0ae8",
                    "empty_layer": true
               }
          ],
          "NamesHistory": [
               "container-registry.oracle.com/os/oraclelinux:9-slim"
          ]
     }
]

Listing Local Images

Use the podman images command to review a list of locally stored container images.

For more information on the podman images command, use the podman-images(1) manual page.

Example 3-5 List local container images

List all the locally stored container images that have already been downloaded from a container registry

podman images

The command provides similar output similar to the following:

REPOSITORY                                    TAG         IMAGE ID      CREATED      SIZE
container-registry.oracle.com/os/oraclelinux  9-slim      46cfa93e021d  5 days ago   117 MB

Deleting a Local Image

Delete a locally stored container image using the podman rmi command.

Container images can't be deleted if they're still in use by a container, even if that container isn't running. You must remove all the containers that depend on a container image before you can remove that container image.

For more information on the podman rmi command, use the podman-rmi(1) manual page.

Example 3-6 Delete a local container image

Delete an image named oraclelinux:9-slim that's stored locally: 

podman rmi oraclelinux:9-slim

The command provides output similar to the following:

Untagged: container-registry.oracle.com/os/oraclelinux:9-slim
Deleted: 46cfa93e021dd2ca65c70112d8d578484c3a9be71d4b05af6c027d4b7ae43182