Merge pull request #2133 from travisn/backport-format-status

Backport: Log the output of blkid to see if device should be formatted

cmd/rookflex/cmd/mount.go

@@ -25,6 +25,7 @@ import (
 	"strings"
 
 	"github.com/rook/rook/pkg/daemon/ceph/agent/flexvolume"
+	"github.com/rook/rook/pkg/util/exec"
 	"github.com/spf13/cobra"
 	k8smount "k8s.io/kubernetes/pkg/util/mount"
 	"k8s.io/kubernetes/pkg/util/version"
@@ -134,6 +135,22 @@ func mountDevice(client *rpc.Client, mounter *k8smount.SafeFormatAndMount, devic
 			return fmt.Errorf("Rook: Mount volume failed. Error checking if %s is a mount point: %v", globalVolumeMountPath, err)
 		}
 	}
+
+	// Testing to see if the device is formatted. There has been observed an issue on slow systems where k8s believes there is no filesystem
+	// formatted even though one does exist. K8s then proceeds to format the volume which would result in data loss. This logging is an attempt
+	// to understand why k8s believes the volume is not formatted. See https://github.com/rook/rook/issues/1553
+	log(client, fmt.Sprintf("Testing to see if device %s needs formatting...", devicePath), false)
+	executor := &exec.CommandExecutor{}
+	output, err := executor.ExecuteCommandWithOutput(false, "", "blkid", "-p", "-s", "TYPE", "-s", "PTTYPE", "-o", "export", devicePath)
+	if err != nil {
+		log(client, fmt.Sprintf("Formatting test (blkid -p -s TYPE -s PTTYPE -o export %s). Device may not be formatted. err: %+v", devicePath, err), false)
+	} else {
+		log(client, fmt.Sprintf("Formatting test (blkid -p -s TYPE -s PTTYPE -o export %s). Device is already formatted", devicePath), false)
+	}
+	if len(output) > 0 {
+		log(client, fmt.Sprintf("Output: %s", output), false)
+	}
+
 	options := []string{opts.RW}
 	if notMnt {
 		err = redirectStdout(