podman-machine-init(1)

NAME
podman-machine-init - Initialize a new virtual machine

SYNOPSIS
podman machine init [options] [name]

DESCRIPTION
Initialize a new virtual machine for Podman.

The default machine name is podman-machine-default. If a machine name is not specified as an argument, then the new machine will be named podman-machine-default.

Rootless only.

Podman on MacOS and Windows requires a virtual machine. This is because containers are Linux - containers do not run on any other OS because containers' core functionality are tied to the Linux kernel. Podman machine must be used to manage MacOS and Windows machines, but can be optionally used on Linux.

podman machine init initializes a new Linux virtual machine where containers are run. SSH keys are automatically generated to access the VM, and system connections to the root account and a user account inside the VM are added.

By default, the VM distribution is a custom Fedora CoreOS based image pushed to quay.io/podman/machine-os (build in https://github.com/containers/podman-machine-os). WSL is an exception and is based on a custom Fedora image.

To check if there is an upgrade available for your machine os, you can run the following command:

    $ podman machine ssh 'sudo rpm-ostree upgrade --check'

If an update is available, you can rerun the above command and remove the --check and your operating system will be updated. After updating, you must stop and start your machine with podman machine stop && podman machine start for it to take effect.

The above mechanism is only used to update patch (Z) versions of podman. For updates to new major and minor version (X.Y) use the podman machine os apply command, see the docs there for more information.

Note: Updating as described above can result in version mismatches between Podman on the host and Podman in the machine. Executing podman info should reveal versions of both. A configuration where the Podman host and machine mismatch are unsupported.

To update the WSL image you must run dnf update inside, use the following command:

    $ podman machine ssh dnf update

Default Podman machine settings can be set via the [machine] section in the containers.conf(5) file.

OPTIONS

  --cpus=number
Number of CPUs.

  --disk-size=number
Size of the disk for the guest VM in GiB.

  --help
Print usage statement.

  --ignition-path
Fully qualified path of the ignition file.

If an ignition file is provided, the file is copied into the user's CONF_DIR and renamed. Additionally, no SSH keys are generated, nor are any system connections made. It is assumed that the user does these things manually or handled otherwise.

  --image
Fully qualified registry, path, or URL to a VM image. Registry target must be in the form of docker://registry/repo/image:version.

Note: Only images provided by podman will be supported.

  --memory, -m=number
Memory (in MiB). Note: 1024MiB = 1GiB.

  --now
Start the virtual machine immediately after it has been initialized.

  --playbook
Add the provided Ansible playbook to the machine and execute it after the first boot.

Note: The playbook will be executed with the same privileges given to the user in the virtual machine. The playbook provided cannot include other files from the host system, as they will not be copied. Use of the --playbook flag will require the image to include Ansible. The default image provided will have Ansible included.

  --rootful
Whether this machine prefers rootful (true) or rootless (false) container execution. This option determines the remote connection default if there is no existing remote connection configurations.

API forwarding, if available, follows this setting.

  --swap, -s=number
Swap (in MiB). Note: 1024MiB = 1GiB.

Renders a zram-generator.conf file with zram-size set to the value passed to --swap

  --timezone
Set the timezone for the machine and containers. Valid values are local or a timezone such as America/Chicago. A value of local, which is the default, means to use the timezone of the machine host.

The timezone setting is not used with WSL. WSL automatically sets the timezone to the same as the host Windows operating system.

  --usb=bus=number,devnum=number or vendor=hexadecimal,product=hexadecimal
Assign a USB device from the host to the VM via USB passthrough. Only supported for QEMU Machines.

The device needs to have proper permissions in order to be passed to the machine. This means the device needs to be under your user group.

Note that using bus and device number are simpler but the values can change every boot or when the device is unplugged.

When specifying a USB using vendor and product ID's, if more than one device has the same vendor and product ID, the first available device is assigned.

  --user-mode-networking
Indicates that this machine relays traffic from the guest through a user-space process running on the host. In some VPN configurations the VPN may drop traffic from alternate network interfaces, including VM network devices. By enabling user-mode networking (a setting of true), VPNs observe all podman machine traffic as coming from the host, bypassing the problem.

When the qemu backend is used (Linux, Mac), user-mode networking is mandatory and the only allowed value is true. In contrast, The Windows/WSL backend defaults to false, and follows the standard WSL network setup. Changing this setting to true on Windows/WSL informs Podman to replace the WSL networking setup on start of this machine instance with a user-mode networking distribution. Since WSL shares the same kernel across distributions, all other running distributions reuses this network. Likewise, when the last machine instance with a true setting stops, the original networking setup is restored.

  --username
Username to use for executing commands in remote VM. Default value is core for FCOS and user for Fedora (default on Windows hosts). Should match the one used inside the resulting VM image.

  --volume, -v=source:target[:options]
Mounts a volume from source to target.

Create a mount. If /host-dir:/machine-dir is specified as the *source:target*, Podman mounts host-dir in the host to machine-dir in the Podman machine.

Additional options may be specified as a comma-separated string. Recognized options are: * ro: mount volume read-only * rw: mount volume read/write (default) * security_model=[model]: specify 9p security model (see below)

Note: The following destinations are forbidden for volumes: /bin, /boot, /dev, /etc, /home, /proc, /root, /run, /sbin, /sys, /tmp, /usr, and /var. Subdirectories of these destinations are allowed but users should be careful to not mount to important directories as unexpected results may occur.

The 9p security model [determines] https://wiki.qemu.org/Documentation/9psetup#Starting_the_Guest_directly if and how the 9p filesystem translates some filesystem operations before actual storage on the host.

In order to allow symlinks to work, on MacOS the default security model is
 none.

The value of mapped-xattr specifies that 9p store symlinks and some file attributes as extended attributes on the host. This is suitable when the host and the guest do not need to interoperate on the shared filesystem, but has caveats for actual shared access; notably, symlinks on the host are not usable on the guest and vice versa. If interoperability is required, then choose none instead, but keep in mind that the guest is not able to do things that the user running the virtual machine cannot do, e.g. create files owned by another user. Using none is almost certainly the best choice for read-only volumes.

Example: -v "$HOME/git:$HOME/git:ro,security_model=none"

Default volume mounts are defined in containers.conf. Unless changed, the default values is $HOME:$HOME.

Note on Windows Subsystem for Linux (WSL) Since all drives are mounted at /mnt on startup by default in WSL, passing --volume is redundant and has no effect. The host home directory for a C: drive will be mounted at /mnt/c/Users/<my username>.

EXAMPLES
Initialize the default Podman machine, pulling the content from the internet.

    $ podman machine init

Initialize a Podman machine for the specified name pulling the content from the internet.

    $ podman machine init myvm

Initialize and start a new Podman machine in one step.

    podman machine init --now

Initialize the default Podman machine pulling the content from the internet defaulting to rootful mode. The default is rootless.

    $ podman machine init --rootful

Initialize the default Podman machine overriding its disk size override, pulling the content from the internet.

    $ podman machine init --disk-size 50

Initialize the specified Podman machine overriding its memory size, pulling the content from the internet.

    $ podman machine init --memory=1024 myvm

Initialize the default Podman machine with the host directory /Users mounted into the VM at /Users.

    $ podman machine init -v /Users:/Users

Initialize the default Podman machine with a usb device passthrough specified with options. Only supported for QEMU Machines.

    $ podman machine init --usb vendor=13d3,product=5406

Initialize the default Podman machine with a usb device passthrough with specified with options. Only supported for QEMU Machines.

    $ podman machine init --usb bus=1,devnum=3

SEE ALSO
podman(1), podman-machine(1), containers.conf(5)

HISTORY
March 2021, Originally compiled by Ashley Cui acui@redhat.com ⟨mailto:acui@redhat.com⟩