When to use Buildah and when to use Podman
Buildah and Podman are two complementary open-source projects that reside on GitHub: Buildah (containers/buildah) and Podman (containers/libpod).
Both Buildah and Podman are command line tools that work on OCI images
and containers. The two projects are related, but differ in their
specialization.
Buildah specializes in building OCI
images. Buildah’s commands replicate all of the commands that are found
in a Dockerfile. Buildah’s goal is also to provide a lower level
coreutils interface to build container images, allowing people to build
containers without requiring a Dockerfile. Buildah’s other goal is to
allow you to use other scripting languages to build container images
without requiring a daemon.
Podman specializes in all of the commands
and functions that help you to maintain and modify those OCI container
images, such as pulling and tagging. It also allows you to create, run,
and maintain those containers. If you can do a command in the Docker
CLI, you can do the same command in the Podman CLI. In fact you can just
alias
podman
for docker
on your machine and you can then build, create and maintain container
images and containers without a daemon being present, just as you always
have.
Although Podman uses Buildah’s build
functionality under the covers to create a container image, the two
projects have differences. The major difference between Podman and
Buildah is their concept of a container. Podman allows users to create traditional containers
and the intent of these containers is to be controlled through the
entirety of a container life cycle (pause, checkpoint/restore, etc).
While Buildah containers are really created just to allow content to be
added to the container image. Each project has a separate
internal representation of a container that is not shared. Because of
this you cannot see Podman containers from within Buildah or vice versa.
However the internal representation of a container image is the same
between Buildah and Podman. Given this, any container image that has
been created, pulled or modified by one can be seen and used by the
other.
Some of the commands between the two
projects overlap significantly but in some cases have slightly different
behaviors. The following table illustrates the commands with some
overlap between the projects.
Reference:
https://developers.redhat.com/blog/2018/11/20/buildah-podman-containers-without-daemons/
Additional Resources
- Intro to Podman in Red Hat Enterprise Linux 7.6
- Podman—The next generation of Linux container tools
- Managing containerized system services with Podman
- Podman: Managing pods and containers in a local container runtime
- CRICTL vs Podman
- Building, running, and managing containers – Red Hat Enterprise Linux 8 documentation
- Upstream community sites: buildah.io and podman.io
- GitHub: Buildah (containers/buildah) and Podman (containers/libpod)
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