cephfs: add a ParseConfigArgv function

The ParseConfigArgv behaves similarly to the same named function in
rados. The command line argv value is parsed by ceph libs and used to
configure the mount object.

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

cephfs/cephfs.go

@@ -70,6 +70,28 @@ func (mount *MountInfo) ReadDefaultConfigFile() error {
 	return getError(ret)
 }
 
+// ParseConfigArgv configures the mount using a unix style command line
+// argument vector.
+//
+// Implements:
+//  int ceph_conf_parse_argv(struct ceph_mount_info *cmount, int argc, const char **argv);
+func (mount *MountInfo) ParseConfigArgv(argv []string) error {
+	if err := mount.validate(); err != nil {
+		return err
+	}
+	if len(argv) == 0 {
+		return ErrEmptyArgument
+	}
+	cargv := make([]*C.char, len(argv))
+	for i := range argv {
+		cargv[i] = C.CString(argv[i])
+		defer C.free(unsafe.Pointer(cargv[i]))
+	}
+
+	ret := C.ceph_conf_parse_argv(mount.mount, C.int(len(cargv)), &cargv[0])
+	return getError(ret)
+}
+
 // SetConfigOption sets the value of the configuration option identified by
 // the given name.
 //

cephfs/cephfs_test.go

@@ -270,6 +270,35 @@ func TestGetSetConfigOption(t *testing.T) {
 	assert.Equal(t, origVal, currVal)
 }
 
+func TestParseConfigArgv(t *testing.T) {
+	mount, err := CreateMount()
+	require.NoError(t, err)
+	require.NotNil(t, mount)
+	defer func() { assert.NoError(t, mount.Release()) }()
+
+	origVal, err := mount.GetConfigOption("log_file")
+	assert.NoError(t, err)
+
+	err = mount.ParseConfigArgv(
+		[]string{"cephfs.test", "--log_file", "/dev/null"})
+	assert.NoError(t, err)
+
+	currVal, err := mount.GetConfigOption("log_file")
+	assert.NoError(t, err)
+	assert.Equal(t, "/dev/null", currVal)
+	assert.NotEqual(t, "/dev/null", origVal)
+
+	// ensure that an empty slice triggers an error (not a crash)
+	err = mount.ParseConfigArgv([]string{})
+	assert.Error(t, err)
+
+	// ensure we get an error for an invalid mount value
+	badMount := &MountInfo{}
+	err = badMount.ParseConfigArgv(
+		[]string{"cephfs.test", "--log_file", "/dev/null"})
+	assert.Error(t, err)
+}
+
 func TestValidate(t *testing.T) {
 	mount, err := CreateMount()
 	assert.NoError(t, err)