Build an Image with Podman and Save It as a Tarball

Original Prepium guide · Written for Kubernetes v1.35 and checked against the official documentation on 6 October 2026. Use a disposable practice cluster. The commands here run on a Linux machine with Podman installed, not inside a Pod; use a throwaway VM or practice node rather than a shared host.

Build an OCI image with Podman, then move it as a tar archive

An image is a stack of filesystem layers plus a small JSON configuration. podman build creates that stack from a Containerfile and a build context, and stores it in local image storage under a name. podman save serializes a stored image, layers, history and tags included, into a single archive that podman load can restore on another machine. CKAD expects you to do this quickly and to know where the name and the archive format come from.

context dir (Containerfile + files) --podman build -t--> local storage: localhost/prepium/motd:0.3
                                                            |
                                    podman save -o ... (docker-archive or oci-archive)
                                                            v
                                                 motd.tar --podman load -i--> same image again

1. Prepare a small build context

mkdir -p ~/prepium-img && cd ~/prepium-img
echo "practice makes permanent" > motd.txt
cat > Containerfile <<'EOF'
FROM docker.io/library/busybox:1.36
COPY motd.txt /motd.txt
CMD ["cat", "/motd.txt"]
EOF

The context is the directory whose files COPY can see. Podman looks for a file named exactly Containerfile or Dockerfile in it; any other filename needs -f. The base image is fully qualified (docker.io/library/...) on purpose: Podman's documentation recommends full references, because a short name such as busybox goes through short-name resolution and can stop at a prompt asking which registry to use.

2. Build and name the image

podman build -t prepium/motd:0.3 ~/prepium-img
podman images
podman run --rm localhost/prepium/motd:0.3

The last argument is the context, not the Containerfile. Because the name you gave has no registry part, Podman stores it as localhost/prepium/motd; podman images shows that in the REPOSITORY column with 0.3 under TAG. Add more names to the same image later with podman tag.

3. Save it in either archive format

podman save -o /tmp/motd-docker.tar localhost/prepium/motd:0.3
podman save --format oci-archive -o /tmp/motd-oci.tar localhost/prepium/motd:0.3
ls -lh /tmp/motd-*.tar
tar -tf /tmp/motd-oci.tar | head

Without --format, podman save writes a docker-archive, which docker load also understands. --format oci-archive writes a tar laid out to the OCI Image Format instead. Two directory formats (oci-dir, docker-dir) also exist; they produce a folder, not a tar file, so they are the wrong choice when a single archive file is wanted. Without -o, the archive goes to standard output, which is why you sometimes see podman save IMAGE > file.tar.

4. Prove the round trip

podman rmi localhost/prepium/motd:0.3
podman load -i /tmp/motd-docker.tar
podman images --filter reference=localhost/prepium/motd

podman load prints a Loaded image: line naming what it restored, and the image is back with its original name and tag. That is the real test of an archive: it loads cleanly and the image runs.

Common mistakes

• Passing the Containerfile path as the final argument. That position is the context directory; use -f for the file.
• Forgetting -o and not redirecting. The archive is written to standard output, which means binary noise in your terminal and no file.
• Confusing save/load with export/import. Export flattens a container's filesystem into one layer with no image history; it is not an image archive.
• Choosing oci-dir or docker-dir when a .tar is expected. The output is a directory.

Cleanup: podman rmi localhost/prepium/motd:0.3, rm -rf ~/prepium-img /tmp/motd-*.tar. References: podman build, podman save, podman load. Next, try fixing a broken Deployment.