Files
podman/pkg/machine/volume_systemd.go
Nicola Sella d6cf6e8495 machine: share virtiofs systemd unit generation
Make GenerateSystemDFilesForVirtiofsMounts an agnostic function
and move the code from apple to pkg/machine/volume_systemd.go

MountVolumesToVM  is now a no-op matching the AppleHV and
LibKrun behaviour.

Continues from PR: https://github.com/podman-container-tools/podman/pull/28736

Fixes: https://redhat.atlassian.net/browse/RUN-4742

Signed-off-by: Nicola Sella <nsella@redhat.com>
2026-06-02 14:47:08 +02:00

87 lines
3.0 KiB
Go

package machine
import (
"fmt"
"go.podman.io/podman/v6/pkg/machine/ignition"
"go.podman.io/podman/v6/pkg/systemd/parser"
)
// GenerateSystemDFilesForVirtiofsMounts generates the systemd unit files needed
// to mount virtiofs volumes inside a FCOS guest VM. It is shared between the
// AppleHV, LibKrun, and QEMU providers.
//
// Mounting in FCOS with virtiofs is a bit of a dance. we need a unit file for
// the mount, a unit file for automatic mounting on boot, and a "preparatory"
// service file that disables FCOS security, performs the mkdir of the mount
// point, and then re-enables security. This must be done for each mount.
func GenerateSystemDFilesForVirtiofsMounts(mounts []VirtIoFs) ([]ignition.Unit, error) {
unitFiles := make([]ignition.Unit, 0, len(mounts)+2)
for _, mnt := range mounts {
// Create mount unit for each mount
mountUnit := parser.NewUnitFile()
mountUnit.Add("Mount", "What", "%s")
mountUnit.Add("Mount", "Where", "%s")
mountUnit.Add("Mount", "Type", "virtiofs")
mountUnit.Add("Mount", "Options", fmt.Sprintf("context=\"%s\"", NFSSELinuxContext))
mountUnit.Add("Install", "WantedBy", "local-fs.target")
mountUnitFile, err := mountUnit.ToString()
if err != nil {
return nil, err
}
virtiofsMount := ignition.Unit{
Enabled: ignition.BoolToPtr(true),
Name: fmt.Sprintf("%s.mount", parser.PathEscape(mnt.Target)),
Contents: ignition.StrToPtr(fmt.Sprintf(mountUnitFile, mnt.Tag, mnt.Target)),
}
unitFiles = append(unitFiles, virtiofsMount)
}
// This is a way to workaround the FCOS limitation of creating directories
// at the rootfs / and then mounting to them.
immutableRootOff := parser.NewUnitFile()
immutableRootOff.Add("Unit", "Description", "Allow systemd to create mount points on /")
immutableRootOff.Add("Unit", "DefaultDependencies", "no")
immutableRootOff.Add("Service", "Type", "oneshot")
immutableRootOff.Add("Service", "ExecStart", "chattr -i /")
immutableRootOff.Add("Install", "WantedBy", "local-fs-pre.target")
immutableRootOffFile, err := immutableRootOff.ToString()
if err != nil {
return nil, err
}
immutableRootOffUnit := ignition.Unit{
Contents: ignition.StrToPtr(immutableRootOffFile),
Name: "immutable-root-off.service",
Enabled: ignition.BoolToPtr(true),
}
unitFiles = append(unitFiles, immutableRootOffUnit)
immutableRootOn := parser.NewUnitFile()
immutableRootOn.Add("Unit", "Description", "Set / back to immutable after mounts are done")
immutableRootOn.Add("Unit", "DefaultDependencies", "no")
immutableRootOn.Add("Unit", "After", "local-fs.target")
immutableRootOn.Add("Service", "Type", "oneshot")
immutableRootOn.Add("Service", "ExecStart", "chattr +i /")
immutableRootOn.Add("Install", "WantedBy", "local-fs.target")
immutableRootOnFile, err := immutableRootOn.ToString()
if err != nil {
return nil, err
}
immutableRootOnUnit := ignition.Unit{
Contents: ignition.StrToPtr(immutableRootOnFile),
Name: "immutable-root-on.service",
Enabled: ignition.BoolToPtr(true),
}
unitFiles = append(unitFiles, immutableRootOnUnit)
return unitFiles, nil
}