feat: support NFS storage pools

internal/server/storage/drivers/driver_nfs.go

@@ -0,0 +1,125 @@
+package drivers
+
+import (
+	"strings"
+
+	"github.com/lxc/incus/v6/internal/linux"
+	"github.com/lxc/incus/v6/internal/migration"
+	deviceConfig "github.com/lxc/incus/v6/internal/server/device/config"
+	localMigration "github.com/lxc/incus/v6/internal/server/migration"
+	"github.com/lxc/incus/v6/shared/util"
+)
+
+type nfs struct {
+	dir
+}
+
+// Info returns info about the driver and its environment.
+func (n *nfs) Info() Info {
+	return Info{
+		Name:                         "nfs",
+		Version:                      "1",
+		DefaultVMBlockFilesystemSize: deviceConfig.DefaultVMBlockFilesystemSize,
+		OptimizedImages:              false,
+		PreservesInodes:              false,
+		Remote:                       n.isRemote(),
+		VolumeTypes:                  []VolumeType{VolumeTypeBucket, VolumeTypeCustom, VolumeTypeImage, VolumeTypeContainer, VolumeTypeVM},
+		VolumeMultiNode:              n.isRemote(),
+		BlockBacking:                 false,
+		RunningCopyFreeze:            false,
+		DirectIO:                     true,
+		MountedRoot:                  true,
+		Buckets:                      true,
+	}
+}
+
+// isRemote returns true indicating this driver uses remote storage.
+func (n *nfs) isRemote() bool {
+	return true
+}
+
+// FillConfig populates the storage pool's configuration file with the default values.
+func (n *nfs) FillConfig() error {
+	uri := strings.Split(n.config["source"], ":")
+
+	// URI should be first part of IP:PORT
+	n.config["nfs.addr"] = uri[0]
+
+	return nil
+}
+
+func (n *nfs) getMountOptions() string {
+	// Allow overriding the default options.
+	if n.config["nfs.mount_options"] != "" {
+		return n.config["nfs.mount_options"]
+	}
+	// We only really support vers=4.2
+	return "vers=4.2,addr=" + n.config["nfs.addr"]
+}
+
+// Create is called during pool creation and is effectively using an empty driver struct.
+// WARNING: The Create() function cannot rely on any of the struct attributes being set.
+func (n *nfs) Create() error {
+	err := n.FillConfig()
+	if err != nil {
+		return err
+	}
+
+	sourcePath := n.config["source"]
+
+	// Mount the nfs driver.
+	mntFlags, mntOptions := linux.ResolveMountOptions(strings.Split(n.getMountOptions(), ","))
+	err = TryMount(sourcePath, GetPoolMountPath(n.name), "nfs4", mntFlags, mntOptions)
+	if err != nil {
+		return err
+	}
+
+	defer func() { _, _ = forceUnmount(GetPoolMountPath(n.name)) }()
+
+	return nil
+}
+
+func (n *nfs) Mount() (bool, error) {
+	path := GetPoolMountPath(n.name)
+
+	// Check if already mounted.
+	if linux.IsMountPoint(path) {
+		return false, nil
+	}
+
+	sourcePath := n.config["source"]
+	n.config["nfs.path"] = sourcePath
+
+	// Check if we're dealing with an external mount.
+	if sourcePath == path {
+		return false, nil
+	}
+
+	// Mount the nfs driver.
+	mntFlags, mntOptions := linux.ResolveMountOptions(strings.Split(n.getMountOptions(), ","))
+	err := TryMount(sourcePath, GetPoolMountPath(n.name), "nfs4", mntFlags, mntOptions)
+	if err != nil {
+		return false, err
+	}
+
+	return true, nil
+}
+
+func (n *nfs) MigrationTypes(contentType ContentType, refresh bool, copySnapshots bool, clusterMove bool, storageMove bool) []localMigration.Type {
+	// NFS does not support xattr
+	rsyncFeatures := []string{"delete", "bidirectional"}
+	if util.IsTrue(n.Config()["rsync.compression"]) {
+		rsyncFeatures = append(rsyncFeatures, "compress")
+	}
+
+	return []localMigration.Type{
+		{
+			FSType:   migration.MigrationFSType_BLOCK_AND_RSYNC,
+			Features: rsyncFeatures,
+		},
+		{
+			FSType:   migration.MigrationFSType_RSYNC,
+			Features: rsyncFeatures,
+		},
+	}
+}

internal/server/storage/drivers/load.go

@@ -15,6 +15,7 @@ var drivers = map[string]func() driver{
 	"lvmcluster": func() driver { return &lvm{clustered: true} },
 	"zfs":        func() driver { return &zfs{} },
 	"linstor":    func() driver { return &linstor{} },
+	"nfs":        func() driver { return &nfs{} },
 }
 
 // Validators contains functions used for validating a drivers's config.