cephfs admin: add a SubVolumeInfo function

Add a SubVolumeInfo function that works like the `ceph fs subvolume
info` command. This function returns a SubVolumeInfo type from parsing
the response JSON.

In order to re-use the existing QuotaSize type, which is an interface
and thus can't be unmarshaled directly, we use a non-exported wrapper
type for the unmarshaling and then we fix up the BytesQuota field so
that users of the library don't need to directly deal with the quota
size placeholder type, which can unmarshal the value.

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

cephfs/admin/subvolume.go

@@ -160,3 +160,54 @@ func (fsa *FSAdmin) SubVolumePath(volume, group, name string) (string, error) {
 	}
 	return extractPathResponse(fsa.marshalMgrCommand(m))
 }
+
+// SubVolumeInfo reports various informational values about a subvolume.
+type SubVolumeInfo struct {
+	Type          string    `json:"type"`
+	Path          string    `json:"path"`
+	Uid           int       `json:"uid"`
+	Gid           int       `json:"gid"`
+	Mode          int       `json:"mode"`
+	BytesPercent  string    `json:"bytes_pcent"`
+	BytesUsed     ByteCount `json:"bytes_used"`
+	BytesQuota    QuotaSize `json:"-"`
+	DataPool      string    `json:"data_pool"`
+	PoolNamespace string    `json:"pool_namespace"`
+	Atime         TimeStamp `json:"atime"`
+	Mtime         TimeStamp `json:"mtime"`
+	Ctime         TimeStamp `json:"ctime"`
+	CreatedAt     TimeStamp `json:"created_at"`
+}
+
+type subVolumeInfoWrapper struct {
+	SubVolumeInfo
+	VBytesQuota *quotaSizePlaceholder `json:"bytes_quota"`
+}
+
+func parseSubVolumeInfo(r []byte, s string, err error) (*SubVolumeInfo, error) {
+	var info subVolumeInfoWrapper
+	if err := unmarshalResponseJSON(r, s, err, &info); err != nil {
+		return nil, err
+	}
+	if info.VBytesQuota != nil {
+		info.BytesQuota = info.VBytesQuota.Value
+	}
+	return &info.SubVolumeInfo, nil
+}
+
+// SubVolumeInfo returns information about the specified subvolume.
+//
+// Similar To:
+//  ceph fs subvolume info <volume> --group-name=<group> <name>
+func (fsa *FSAdmin) SubVolumeInfo(volume, group, name string) (*SubVolumeInfo, error) {
+	m := map[string]string{
+		"prefix":   "fs subvolume info",
+		"vol_name": volume,
+		"sub_name": name,
+		"format":   "json",
+	}
+	if group != NoGroup {
+		m["group_name"] = group
+	}
+	return parseSubVolumeInfo(fsa.marshalMgrCommand(m))
+}

cephfs/admin/subvolume_test.go

@@ -3,6 +3,7 @@
 package admin
 
 import (
+	"errors"
 	"testing"
 	"time"
 
@@ -205,3 +206,144 @@ func TestSubVolumePath(t *testing.T) {
 	assert.Error(t, err)
 	assert.Equal(t, "", path)
 }
+
+var sampleSubVolumeInfo1 = []byte(`
+{
+    "atime": "2020-08-31 19:53:43",
+    "bytes_pcent": "undefined",
+    "bytes_quota": "infinite",
+    "bytes_used": 0,
+    "created_at": "2020-08-31 19:53:43",
+    "ctime": "2020-08-31 19:57:15",
+    "data_pool": "cephfs_data",
+    "gid": 0,
+    "mode": 16877,
+    "mon_addrs": [
+        "127.0.0.1:6789"
+    ],
+    "mtime": "2020-08-31 19:53:43",
+    "path": "/volumes/_nogroup/nibbles/df11be81-a648-4a7b-8549-f28306e3ad93",
+    "pool_namespace": "",
+    "type": "subvolume",
+    "uid": 0
+}
+`)
+
+var sampleSubVolumeInfo2 = []byte(`
+{
+    "atime": "2020-09-01 17:49:25",
+    "bytes_pcent": "0.00",
+    "bytes_quota": 444444,
+    "bytes_used": 0,
+    "created_at": "2020-09-01 17:49:25",
+    "ctime": "2020-09-01 23:49:22",
+    "data_pool": "cephfs_data",
+    "gid": 0,
+    "mode": 16877,
+    "mon_addrs": [
+        "127.0.0.1:6789"
+    ],
+    "mtime": "2020-09-01 17:49:25",
+    "path": "/volumes/_nogroup/nibbles/d6e062df-7fa0-46ca-872a-9adf728e0e00",
+    "pool_namespace": "",
+    "type": "subvolume",
+    "uid": 0
+}
+`)
+
+var badSampleSubVolumeInfo1 = []byte(`
+{
+    "bytes_quota": "fishy",
+    "uid": 0
+}
+`)
+
+var badSampleSubVolumeInfo2 = []byte(`
+{
+    "bytes_quota": true,
+    "uid": 0
+}
+`)
+
+func TestParseSubVolumeInfo(t *testing.T) {
+	t.Run("error", func(t *testing.T) {
+		_, err := parseSubVolumeInfo(nil, "", errors.New("gleep glop"))
+		assert.Error(t, err)
+		assert.Equal(t, "gleep glop", err.Error())
+	})
+	t.Run("statusSet", func(t *testing.T) {
+		_, err := parseSubVolumeInfo(nil, "unexpected!", nil)
+		assert.Error(t, err)
+	})
+	t.Run("ok", func(t *testing.T) {
+		info, err := parseSubVolumeInfo(sampleSubVolumeInfo1, "", nil)
+		assert.NoError(t, err)
+		if assert.NotNil(t, info) {
+			assert.Equal(t,
+				"/volumes/_nogroup/nibbles/df11be81-a648-4a7b-8549-f28306e3ad93",
+				info.Path)
+			assert.Equal(t, 0, info.Uid)
+			assert.Equal(t, Infinite, info.BytesQuota)
+			assert.Equal(t, 040755, info.Mode)
+			assert.Equal(t, 2020, info.Ctime.Year())
+			assert.Equal(t, "2020-08-31 19:57:15", info.Ctime.String())
+		}
+	})
+	t.Run("ok2", func(t *testing.T) {
+		info, err := parseSubVolumeInfo(sampleSubVolumeInfo2, "", nil)
+		assert.NoError(t, err)
+		if assert.NotNil(t, info) {
+			assert.Equal(t,
+				"/volumes/_nogroup/nibbles/d6e062df-7fa0-46ca-872a-9adf728e0e00",
+				info.Path)
+			assert.Equal(t, 0, info.Uid)
+			assert.Equal(t, ByteCount(444444), info.BytesQuota)
+			assert.Equal(t, 040755, info.Mode)
+			assert.Equal(t, 2020, info.Ctime.Year())
+			assert.Equal(t, "2020-09-01 23:49:22", info.Ctime.String())
+		}
+	})
+	t.Run("invalidBytesQuotaValue", func(t *testing.T) {
+		info, err := parseSubVolumeInfo(badSampleSubVolumeInfo1, "", nil)
+		assert.Error(t, err)
+		assert.Nil(t, info)
+	})
+	t.Run("invalidBytesQuotaType", func(t *testing.T) {
+		info, err := parseSubVolumeInfo(badSampleSubVolumeInfo2, "", nil)
+		assert.Error(t, err)
+		assert.Nil(t, info)
+	})
+}
+
+func TestSubVolumeInfo(t *testing.T) {
+	fsa := getFSAdmin(t)
+	volume := "cephfs"
+	group := "hoagie"
+	subname := "grinder"
+
+	err := fsa.CreateSubVolumeGroup(volume, group, nil)
+	assert.NoError(t, err)
+	defer func() {
+		err := fsa.RemoveSubVolumeGroup(volume, group)
+		assert.NoError(t, err)
+	}()
+
+	svopts := &SubVolumeOptions{
+		Mode: 0750,
+		Size: 20 * gibiByte,
+	}
+	err = fsa.CreateSubVolume(volume, group, subname, svopts)
+	assert.NoError(t, err)
+	defer func() {
+		err := fsa.RemoveSubVolume(volume, group, subname)
+		assert.NoError(t, err)
+	}()
+
+	vinfo, err := fsa.SubVolumeInfo(volume, group, subname)
+	assert.NoError(t, err)
+	assert.NotNil(t, vinfo)
+	assert.Equal(t, 0, vinfo.Uid)
+	assert.Equal(t, 20*gibiByte, vinfo.BytesQuota)
+	assert.Equal(t, 040750, vinfo.Mode)
+	assert.GreaterOrEqual(t, 2020, vinfo.Ctime.Year())
+}