ceph: expose operator ceph base image

We now have a new env variable ROOK_CEPH_BASE_IMAGE_VERSION which
contains the ceph version on the operator image.

Signed-off-by: Sébastien Han <seb@redhat.com>

cmd/rook/ceph/operator.go

@@ -17,6 +17,8 @@ limitations under the License.
 package ceph
 
 import (
+	"os"
+
 	"github.com/pkg/errors"
 	"github.com/rook/rook/cmd/rook/rook"
 	"github.com/rook/rook/pkg/clusterd"
@@ -31,7 +33,10 @@ import (
 	"github.com/spf13/cobra"
 )
 
-const containerName = "rook-ceph-operator"
+const (
+	containerName                = "rook-ceph-operator"
+	operatorCephBaseImageVersion = "ROOK_CEPH_BASE_IMAGE_VERSION"
+)
 
 var operatorCmd = &cobra.Command{
 	Use:   "operator",
@@ -79,6 +84,8 @@ func startOperator(cmd *cobra.Command, args []string) error {
 	}
 
 	rookImage := rook.GetOperatorImage(context.Clientset, containerName)
+	rookBaseImageCephVersion := rook.GetOperatorBaseImageCephVersion(context)
+	os.Setenv(operatorCephBaseImageVersion, rookBaseImageCephVersion)
 	serviceAccountName := rook.GetOperatorServiceAccount(context.Clientset)
 	op := operator.New(context, volumeAttachment, rookImage, serviceAccountName)
 	err = op.Run()

cmd/rook/rook/rook.go

@@ -217,3 +217,14 @@ func TerminateFatal(reason error) {
 
 	os.Exit(1)
 }
+
+// GetOperatorBaseImageCephVersion returns the Ceph version of the operator image
+func GetOperatorBaseImageCephVersion(context *clusterd.Context) string {
+	output, err := context.Executor.ExecuteCommandWithOutput("ceph", "--version")
+	if err != nil {
+		logger.Errorf("failed to discover ceph base image version. %v", err)
+		return ""
+	}
+
+	return output
+}