v4.1.0-RC2

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.
• The podman machine set command can now change the CPUs, memory, and disk space available to machines after they were initially created, using the new --cpus, --disk-size, and --memory options (#13633).
• Podman now supports sending JSON events related to machines to a Unix socket named machine_events.*\.sock in XDG_RUNTIME_DIR/podman or to a socket whose path is set in the PODMAN_MACHINE_EVENTS_SOCK environment variable.
• 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.
• The podman images --format command now accepts two new format directives: {{.CreatedAt}} and {{.CreatedSince}} (#14012).
• The podman volume create command's -o option now accepts a new argument, o=noquota, to disable XFS quotas entirely and avoid potential issues when Podman is run on an XFS filesystem with existing quotas defined (#14049).
• The podman info command now includes additional information on the machine Podman is running on, including disk utilization on the drive Podman is storing containers and images on, and CPU utilization (#13876).

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.
• The --no-trunc flag to podman search now defaults to false, to ensure output is not overly verbose.

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.
• Fixed a bug where the podman pod inspect command incorrectly reported whether the pod used the host's network (#14028).
• Fixed a bug where Podman would, when run on WSL2, ports specified without an IP address (e.g. -p 8080:8080) would be bound to IPv6 addresses (#12292).

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.