util: add support to configure mirror daemon count

Currently we are assuming that only one
rbd mirror daemon running on the ceph cluster
but that is not true for many cases and it
can be more that one, this PR make this as a
configurable parameter.

fixes: #4312

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>

internal/util/csiconfig_test.go

@@ -17,11 +17,14 @@ limitations under the License.
 package util
 
 import (
+	"bytes"
 	"encoding/json"
 	"os"
 	"testing"
 
 	cephcsi "github.com/ceph/ceph-csi/api/deploy/kubernetes"
+
+	"github.com/stretchr/testify/require"
 )
 
 var (
@@ -530,3 +533,88 @@ func TestGetCephFSMountOptions(t *testing.T) {
 		})
 	}
 }
+
+func TestGetRBDMirrorDaemonCount(t *testing.T) {
+	t.Parallel()
+	tests := []struct {
+		name      string
+		clusterID string
+		want      int
+	}{
+		{
+			name:      "get rbd mirror daemon count for cluster-1",
+			clusterID: "cluster-1",
+			want:      2,
+		},
+		{
+			name:      "get rbd mirror daemon count for cluster-2",
+			clusterID: "cluster-2",
+			want:      4,
+		},
+		{
+			name:      "when rbd mirror daemon count is empty",
+			clusterID: "cluster-3",
+			want:      1, // default mirror daemon count
+		},
+	}
+
+	csiConfig := []cephcsi.ClusterInfo{
+		{
+			ClusterID: "cluster-1",
+			Monitors:  []string{"ip-1", "ip-2"},
+			RBD: cephcsi.RBD{
+				MirrorDaemonCount: 2,
+			},
+		},
+		{
+			ClusterID: "cluster-2",
+			Monitors:  []string{"ip-3", "ip-4"},
+			RBD: cephcsi.RBD{
+				MirrorDaemonCount: 4,
+			},
+		},
+		{
+			ClusterID: "cluster-3",
+			Monitors:  []string{"ip-5", "ip-6"},
+		},
+	}
+	csiConfigFileContent, err := json.Marshal(csiConfig)
+	if err != nil {
+		t.Errorf("failed to marshal csi config info %v", err)
+	}
+	tmpConfPath := t.TempDir() + "/ceph-csi.json"
+	err = os.WriteFile(tmpConfPath, csiConfigFileContent, 0o600)
+	if err != nil {
+		t.Errorf("failed to write %s file content: %v", CsiConfigFile, err)
+	}
+	for _, tt := range tests {
+		ts := tt
+		t.Run(ts.name, func(t *testing.T) {
+			t.Parallel()
+			var got int
+			got, err = GetRBDMirrorDaemonCount(tmpConfPath, ts.clusterID)
+			if err != nil {
+				t.Errorf("GetRBDMirrorDaemonCount() error = %v", err)
+
+				return
+			}
+			if got != ts.want {
+				t.Errorf("GetRBDMirrorDaemonCount() = %v, want %v", got, ts.want)
+			}
+		})
+	}
+
+	// when mirrorDaemonCount is set as string
+	csiConfigFileContent = bytes.Replace(
+		csiConfigFileContent,
+		[]byte(`"mirrorDaemonCount":2`),
+		[]byte(`"mirrorDaemonCount":"2"`),
+		1)
+	tmpCSIConfPath := t.TempDir() + "/ceph-csi.json"
+	err = os.WriteFile(tmpCSIConfPath, csiConfigFileContent, 0o600)
+	if err != nil {
+		t.Errorf("failed to write %s file content: %v", CsiConfigFile, err)
+	}
+	_, err = GetRBDMirrorDaemonCount(tmpCSIConfPath, "test")
+	require.Error(t, err)
+}