cephfs admin: add functions to create, list, & delete subvolumegroups

Adds functions and tests for:
* CreateSubVolumeGroup
* ListSubVolumeGroups
* RemoveSubVolumeGroup

Signed-off-by: John Mulligan <jmulligan@redhat.com>

cephfs/admin/subvolumegroup.go

@@ -0,0 +1,69 @@
+package admin
+
+// this is the internal type used to create JSON for ceph.
+// See SubVolumeGroupOptions for the type that users of the library
+// interact with.
+// note that the ceph json takes mode as a string.
+type subVolumeGroupFields struct {
+	Prefix     string `json:"prefix"`
+	Format     string `json:"format"`
+	VolName    string `json:"vol_name"`
+	GroupName  string `json:"group_name"`
+	Uid        int    `json:"uid,omitempty"`
+	Gid        int    `json:"gid,omitempty"`
+	Mode       string `json:"mode,omitempty"`
+	PoolLayout string `json:"pool_layout,omitempty"`
+}
+
+// SubVolumeGroupOptions are used to specify optional, non-identifying, values
+// to be used when creating a new subvolume group.
+type SubVolumeGroupOptions struct {
+	Uid        int
+	Gid        int
+	Mode       int
+	PoolLayout string
+}
+
+func (s *SubVolumeGroupOptions) toFields(v, g string) *subVolumeGroupFields {
+	return &subVolumeGroupFields{
+		Prefix:     "fs subvolumegroup create",
+		Format:     "json",
+		VolName:    v,
+		GroupName:  g,
+		Uid:        s.Uid,
+		Gid:        s.Gid,
+		Mode:       modeString(s.Mode, false),
+		PoolLayout: s.PoolLayout,
+	}
+}
+
+// CreateSubVolumeGroup sends a request to create a subvolume group in a volume.
+func (fsa *FSAdmin) CreateSubVolumeGroup(volume, name string, o *SubVolumeGroupOptions) error {
+	if o == nil {
+		o = &SubVolumeGroupOptions{}
+	}
+	r, s, err := fsa.marshalMgrCommand(o.toFields(volume, name))
+	return checkEmptyResponseExpected(r, s, err)
+}
+
+// ListSubVolumeGroups returns a list of subvolume groups belonging to the
+// specified volume.
+func (fsa *FSAdmin) ListSubVolumeGroups(volume string) ([]string, error) {
+	r, s, err := fsa.marshalMgrCommand(map[string]string{
+		"prefix":   "fs subvolumegroup ls",
+		"vol_name": volume,
+		"format":   "json",
+	})
+	return parseListNames(r, s, err)
+}
+
+// RemoveSubVolumeGroup will delete a subvolume group in a volume.
+func (fsa *FSAdmin) RemoveSubVolumeGroup(volume, name string) error {
+	r, s, err := fsa.marshalMgrCommand(map[string]string{
+		"prefix":     "fs subvolumegroup rm",
+		"vol_name":   volume,
+		"group_name": name,
+		"format":     "json",
+	})
+	return checkEmptyResponseExpected(r, s, err)
+}

cephfs/admin/subvolumegroup_test.go

@@ -0,0 +1,87 @@
+package admin
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestCreateSubVolumeGroup(t *testing.T) {
+	fsa := getFSAdmin(t)
+	volume := "cephfs"
+	created := []string{}
+	defer func() {
+		for _, name := range created {
+			err := fsa.RemoveSubVolumeGroup(volume, name)
+			assert.NoError(t, err)
+		}
+	}()
+
+	t.Run("simple", func(t *testing.T) {
+		svgroup := "svg1"
+		err := fsa.CreateSubVolumeGroup(volume, svgroup, nil)
+		assert.NoError(t, err)
+		created = append(created, svgroup)
+
+		lsvg, err := fsa.ListSubVolumeGroups(volume)
+		assert.NoError(t, err)
+		assert.GreaterOrEqual(t, len(lsvg), 1)
+		assert.Contains(t, lsvg, svgroup)
+	})
+
+	t.Run("options1", func(t *testing.T) {
+		svgroup := "svg2"
+		err := fsa.CreateSubVolumeGroup(volume, svgroup, &SubVolumeGroupOptions{
+			Mode: 0777,
+		})
+		assert.NoError(t, err)
+		created = append(created, svgroup)
+
+		lsvg, err := fsa.ListSubVolumeGroups(volume)
+		assert.NoError(t, err)
+		assert.GreaterOrEqual(t, len(lsvg), 1)
+		assert.Contains(t, lsvg, svgroup)
+	})
+
+	t.Run("options2", func(t *testing.T) {
+		svgroup := "anotherSVG"
+		err := fsa.CreateSubVolumeGroup(volume, svgroup, &SubVolumeGroupOptions{
+			Uid:  200,
+			Gid:  200,
+			Mode: 0771,
+			// TODO: test pool_layout... I think its a pool name
+		})
+		assert.NoError(t, err)
+		created = append(created, svgroup)
+
+		lsvg, err := fsa.ListSubVolumeGroups(volume)
+		assert.NoError(t, err)
+		assert.GreaterOrEqual(t, len(lsvg), 1)
+		assert.Contains(t, lsvg, svgroup)
+	})
+}
+
+func TestRemoveSubVolumeGroup(t *testing.T) {
+	fsa := getFSAdmin(t)
+	volume := "cephfs"
+
+	lsvg, err := fsa.ListSubVolumeGroups(volume)
+	assert.NoError(t, err)
+	beforeCount := len(lsvg)
+
+	err = fsa.CreateSubVolumeGroup(volume, "deleteme1", nil)
+	assert.NoError(t, err)
+
+	lsvg, err = fsa.ListSubVolumeGroups(volume)
+	assert.NoError(t, err)
+	afterCount := len(lsvg)
+	assert.Equal(t, beforeCount, afterCount-1)
+
+	err = fsa.RemoveSubVolumeGroup(volume, "deleteme1")
+	assert.NoError(t, err)
+
+	lsvg, err = fsa.ListSubVolumeGroups(volume)
+	assert.NoError(t, err)
+	nowCount := len(lsvg)
+	assert.Equal(t, beforeCount, nowCount)
+}