v4.1.0-RC1

Features

• Podman now supports Docker Compose v2.2 and higher (#11822).
• A new container command has been added, podman container clone. This command makes a copy of an existing container, with the ability to change some settings (e.g. resource limits) while doing so.
• A new machine command has been added, podman machine inspect. This command provides details on the configuration of machine VMs.
• Two new volume commands have been added, podman volume mount and podman volume unmount. These allow for Podman-managed named volumes to be mounted and accessed from outside containers (#12768).
• VMs created by podman machine now automatically mount the host's $HOME into the VM, to allow mounting volumes from the host into containers.
• The podman container checkpoint and podman container restore options now support checkpointing to and restoring from OCI images. This allows checkpoints to be distributed via standard image registries.
• The podman play kube command now supports environment variables that are specified using the fieldRef and resourceFieldRef sources.
• The podman play kube command will now set default resource limits when the provided YAML does not include them (#13115).
• The podman play kube command now supports a new option, --annotation, to add annotations to created containers (#12968).
• The podman play kube --build command now supports a new option, --context-dir, which allows the user to specify the context directory to use when building the Containerfile (#12485).
• The podman container commit command now supports a new option, --squash, which squashes the generated image into a single layer (#12889).
• The podman pod logs command now supports two new options, --names, which identifies which container generated a log message by name, instead of ID (#13261) and --color, which colors messages based on what container generated them (#13266).
• The podman rmi command now supports a new option, --ignore, which will ignore errors caused by missing images.
• The podman network create command now features a new option, --ipam-driver, to specify details about how IP addresses are assigned to containers in the network (#13521).
• The podman machine list command now features a new option, --quiet, to print only the names of configured VMs and no other information.
• The --ipc option to the podman create, podman run, and podman pod create commands now supports three new modes: none, private, and shareable. The default IPC mode is now shareable, indicating the the IPC namespace can be shared with other containers (#13265).
• The --mount option to the podman create and podman run commands can now set options for created named volumes via the volume-opt parameter (#13387).
• The --mount option to the podman create and podman run commands now allows parameters to be passed in CSV format (#13922).
• The --userns option to the podman create and podman run commands now supports a new option, nomap, that (only for rootless containers) does not map the UID of the user that started the container into the container, increasing security.
• The podman import command now supports three new options, --arch, --os, and --variant, to specify what system the imported image was built for.
• The podman inspect command now includes information on the network configuration of containers that joined a pre-configured network namespace with the --net ns: option to podman run, podman create, and podman pod create.
• The podman run and podman create commands now support a new option, --chrootdirs, which specifies additional locations where container-specific files managed by Podman (e.g. /etc/hosts, `/etc/resolv.conf, etc) will be mounted inside the container (#12961).
• The podman run and podman create commands now support a new option, --passwd-entry, allowing entries to be added to the container's /etc/passwd file.

Changes

• The --net=container: option to podman run, podman create, and podman pod create now conflicts with the --add-host option.
• As part of a deprecation of the SHA1 hash algorithm within Podman, the algorithm used to generate the filename of the rootless network namespace has been changed. As a result, rootless containers started before updating to Podman 4.1.0 will need to be restarted if they are joined to a network (and not just using slirp4netns) to ensure they can connect to containers started the upgrade.
• Podman's handling of the /etc/hosts file has been rewritten to improve its consistency and handling of edge cases (#12003 and #13224). As part of this, two new options are available in containers.conf: base_hosts_file (to specify a nonstandard location to source the base contents of the container's /etc/hosts) and host_containers_internal_ip (to specify a specific IP address for containers' host.containers.internal entry to point to).
• The output of the podman image trust show command now includes information on the transport mechanisms allowed.
• Podman now exits cleanly (with exit code 0) after receiving SIGTERM.
• Containers running in systemd mode now set the container_uuid environment variable (#13187).
• Renaming a container now generates an event readable through podman events.
• The --privileged and --cap-add flags are no longer mutually exclusive (#13449).
• Fixed a bug where the --mount option to podman create and podman run could not create anonymous volumes (#13756).
• Fixed a bug where Podman containers where the user did not explicitly set an OOM score adjustment would implicitly set a value of 0, instead of not setting one at all (#13731).
• The podman machine set command can no longer be used while the VM being updated is running (#13783).
• Systemd service files created by podman generate systemd are now prettyprinted for increased readability.
• The file event log driver now automatically rotates the log file, preventing it from growing beyond a set size.

Bugfixes

• Fixed a bug where Podman could not add devices with a major or minor number over 256 to containers.
• Fixed a bug where containers created by the podman play kube command did not record the raw image name used to create containers.
• Fixed a bug where VMs created by podman machine could not start containers which forwarded ports when run on a host with a proxy configured (#13628).
• Fixed a bug where VMs created by the podman machine command could not be connected to when the username of the current user was sufficiently long (#12751).
• Fixed a bug where the podman machine rm command would error when removing a VM that was never started (#13834).
• Fixed a bug where the remote Podman client's podman manifest push command could not push to registries that required authentication (#13629).
• Fixed a bug where containers joining a pod with volumes did not have the pod's volumes added (#13548).
• Fixed a bug where the podman version --format command could not return the OS of the server (#13690).
• Fixed a bug where the podman play kube command would error when a volume specified by a configMap already existed (#13715).
• Fixed a bug where the podman play kube command did not respect the hostNetwork setting in Pod YAML (#14015).
• Fixed a bug where the podman generate kube command could generate YAML with too-long labels (#13962).
• Fixed a bug where the podman logs --tail=1 command would fail when the log driver was journald and the container was restarted (#13098).
• Fixed a bug where containers created from images with a healthcheck that did not specify an interval would never run their healthchecks (#13912).
• Fixed a bug where the podman network connect and podman network disconnect commands could leave invalid entries in /etc/hosts (#13533).
• Fixed a bug where the --tls-verify option to the remote Podman client's podman build command was nonfunctional.

API

• Containers created via the Libpod Create API that set a memory limit, but not a swap limit, will automatically have a swap limit set (#13145).
• The Compat and Libpod Attach APIs for Containers can now attach to Stopped containers.
• Fixed a bug where the Compat and Libpod Create APIs for Containers did not respect the no_hosts option in containers.conf (#13719).
• Fixed a bug where the default network mode for rootless containers created via the Compat Create API was not bridge.
• Fixed a bug where the Libpod List API for Containers did not allow filtering based on the removing status (#13986).
• Fixed a bug where the Libpod Modify endpoint for Manifests did not respect the tlsVerify parameter.

Misc

• A number of dependencies have been pruned from the project, resulting in a significant reduction in the size of the Podman binary.
• Using podman play kube on a YAML that only includes configMap objects (and no pods or deployments) now prints a much clearer error message.