Add podman machine restart subcommand

[jaitjacob]

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Does this PR introduce a user-facing change?

Yes? No action needed when upgrading?

Fixes #28366

This PR implements podman machine restart subcommand.

Here's how I tested it,

1. Locally build podman binary using make BUILDTAGS="selinux seccomp" PREFIX=/usr
2. cd bin/
3. Run ./podman machine restart --help & verify help text displays correctly.

jaitjacob@fedora:~/Documents/workbench/podman/bin$ ./podman machine restart --help
Restart an existing machine

Description:
  Restart a managed virtual machine

Usage:
  podman machine restart [MACHINE]

Examples:
  podman machine restart podman-machine-default

5. Run ./podman machine list

jaitjacob@fedora:~/Documents/workbench/podman/bin$ ./podman machine list
NAME                     VM TYPE     CREATED      LAST UP            CPUS        MEMORY      DISK SIZE
podman-machine-default*  qemu        3 hours ago  About an hour ago  2           2GiB        10GiB

6. Run ./podman machine start

jaitjacob@fedora:~/Documents/workbench/podman/bin$ ./podman machine start
Starting machine "podman-machine-default"

This machine is currently configured in rootless mode. If your containers
require root permissions (e.g. ports < 1024), or if you run into compatibility
issues with non-podman clients, you can switch using the following command:

        podman machine set --rootful

Mounting volume... /home/jaitjacob:/home/jaitjacob
API forwarding listening on: /run/user/1000/podman/podman-machine-default-api.sock
You can connect Docker API clients by setting DOCKER_HOST using the
following command in your terminal session:

        export DOCKER_HOST='unix:///run/user/1000/podman/podman-machine-default-api.sock'

Machine "podman-machine-default" started successfully

7. SSH into VM and check uptime

jaitjacob@fedora:~/Documents/workbench/podman/bin$ ./podman machine ssh
Connecting to vm podman-machine-default. To close connection, use `~.` or `exit`
Fedora CoreOS 43.20260316.3.1
Tracker: https://github.com/coreos/fedora-coreos-tracker
Discuss: https://discussion.fedoraproject.org/tag/coreos

Last login: Mon May 11 22:26:20 2026 from 192.168.127.1
core@localhost:~$ uptime -p
up 0 minutes
core@localhost:~$ uptime -s
2026-05-12 00:36:59

8. Wait couple mins and run ./podman machine restart

jaitjacob@fedora:~/Documents/workbench/podman/bin$ ./podman machine restart
Waiting for VM to exit...
Machine "podman-machine-default" stopped successfully

This machine is currently configured in rootless mode. If your containers
require root permissions (e.g. ports < 1024), or if you run into compatibility
issues with non-podman clients, you can switch using the following command:

        podman machine set --rootful

Mounting volume... /home/jaitjacob:/home/jaitjacob
API forwarding listening on: /run/user/1000/podman/podman-machine-default-api.sock
You can connect Docker API clients by setting DOCKER_HOST using the
following command in your terminal session:

        export DOCKER_HOST='unix:///run/user/1000/podman/podman-machine-default-api.sock'

Machine "podman-machine-default" started successfully

10. SSH into VM and Check uptime again

jaitjacob@fedora:~/Documents/workbench/podman/bin$ ./podman machine ssh
Connecting to vm podman-machine-default. To close connection, use `~.` or `exit`
Fedora CoreOS 43.20260316.3.1
Tracker: https://github.com/coreos/fedora-coreos-tracker
Discuss: https://discussion.fedoraproject.org/tag/coreos

Last login: Tue May 12 00:37:17 2026 from 192.168.127.1
core@localhost:~$ uptime -p
up 0 minutes
core@localhost:~$ uptime -s
2026-05-12 00:39:14

I also built the docs locally and viewed in browser,

[TomSweeneyRedHat]

this needs to change.

[TomSweeneyRedHat]

Suggested change

	Stopping an already stopped vm is not considered an error so running restart on a stopped vm just
	Stopping an already stopped virtual machine is not considered an error so running restart on a stopped virtual machine just

I realize this was probably a cut/paste form elsewhere, but we say "virtual machine" everywhere else in this doc, so we should be consistant.

[TomSweeneyRedHat]

This needs to be in alpha order between reset and rm

[TomSweeneyRedHat]

@jaitjacob TYVM for the PR! It looks great overall. You should add a test or two if possible, and there are a few tweaks to do to the documenation.

By far the best description I've seen on a PR in a very long time!

[Honny1]

Thanks! At first glance, the code looks good. However, the PR is missing tests. Please implement e2e tests for machine. Here is an example you can use as a reference: https://github.com/containers/podman/blob/main/pkg/machine/e2e/start_test.go. You can add a restart_test.go file for this.