dynamic host volumes: add -id arg for updates of existing volumes (#24996)

If you create a volume via `volume create/register` and want to update it later,
you need to change the volume spec to add the ID that was returned. This isn't a
very nice UX, so let's add an `-id` argument that allows you to update existing
volumes that have that ID.

Ref: https://hashicorp.atlassian.net/browse/NET-12083

command/volume_create.go

@@ -42,6 +42,10 @@ Create Options:
     command. If -detach is omitted or false, the command will monitor the state
     of the volume until it is ready to be scheduled.
 
+  -id
+    Update a volume previously created with this ID prefix. Used for dynamic
+    host volumes only.
+
   -verbose
     Display full information when monitoring volume state. Used for dynamic host
     volumes only.
@@ -60,6 +64,7 @@ func (c *VolumeCreateCommand) AutocompleteFlags() complete.Flags {
 			"-detach":          complete.PredictNothing,
 			"-verbose":         complete.PredictNothing,
 			"-policy-override": complete.PredictNothing,
+			"-id":              complete.PredictNothing,
 		})
 }
 
@@ -75,10 +80,12 @@ func (c *VolumeCreateCommand) Name() string { return "volume create" }
 
 func (c *VolumeCreateCommand) Run(args []string) int {
 	var detach, verbose, override bool
+	var volID string
 	flags := c.Meta.FlagSet(c.Name(), FlagSetClient)
 	flags.BoolVar(&detach, "detach", false, "detach from monitor")
 	flags.BoolVar(&verbose, "verbose", false, "display full volume IDs")
 	flags.BoolVar(&override, "policy-override", false, "override soft mandatory Sentinel policies")
+	flags.StringVar(&volID, "id", "", "update an existing dynamic host volume")
 	flags.Usage = func() { c.Ui.Output(c.Help()) }
 
 	if err := flags.Parse(args); err != nil {
@@ -129,7 +136,7 @@ func (c *VolumeCreateCommand) Run(args []string) int {
 	case "csi":
 		return c.csiCreate(client, ast)
 	case "host":
-		return c.hostVolumeCreate(client, ast, detach, verbose, override)
+		return c.hostVolumeCreate(client, ast, detach, verbose, override, volID)
 	default:
 		c.Ui.Error(fmt.Sprintf("Error unknown volume type: %s", volType))
 		return 1

command/volume_create_host.go

@@ -19,13 +19,34 @@ import (
 )
 
 func (c *VolumeCreateCommand) hostVolumeCreate(
-	client *api.Client, ast *ast.File, detach, verbose, override bool) int {
+	client *api.Client, ast *ast.File, detach, verbose, override bool, volID string) int {
 
 	vol, err := decodeHostVolume(ast)
 	if err != nil {
 		c.Ui.Error(fmt.Sprintf("Error decoding the volume definition: %s", err))
 		return 1
 	}
+	if volID != "" {
+		ns := c.namespace
+		if vol.Namespace != "" {
+			ns = vol.Namespace
+		}
+		stub, possible, err := getHostVolumeByPrefix(client, volID, ns)
+		if err != nil {
+			c.Ui.Error(fmt.Sprintf("Could not update existing volume: %s", err))
+			return 1
+		}
+		if len(possible) > 0 {
+			out, err := formatHostVolumes(possible, formatOpts{short: true})
+			if err != nil {
+				c.Ui.Error(fmt.Sprintf("Error formatting: %s", err))
+				return 1
+			}
+			c.Ui.Error(fmt.Sprintf("Prefix matched multiple volumes\n\n%s", out))
+			return 1
+		}
+		vol.ID = stub.ID
+	}
 
 	req := &api.HostVolumeCreateRequest{
 		Volume:         vol,
@@ -44,7 +65,6 @@ func (c *VolumeCreateCommand) hostVolumeCreate(
 				fmt.Sprintf("[bold][yellow]Volume Warnings:\n%s[reset]\n", resp.Warnings)))
 	}
 
-	var volID string
 	var lastIndex uint64
 
 	if detach || vol.State == api.HostVolumeStateReady {

command/volume_create_host_test.go

@@ -80,6 +80,13 @@ parameters {
 	got, _, err := client.HostVolumes().Get(id, &api.QueryOptions{Namespace: "prod"})
 	must.NoError(t, err)
 	must.NotNil(t, got)
+
+	// Verify we can update the volume without changes
+	args = []string{"-address", url, "-detach", "-id", got.ID, file.Name()}
+	code = cmd.Run(args)
+	must.Eq(t, 0, code, must.Sprintf("got error: %s", ui.ErrorWriter.String()))
+	list, _, err := client.HostVolumes().List(nil, &api.QueryOptions{Namespace: "prod"})
+	must.Len(t, 1, list, must.Sprintf("new volume should not be created on update"))
 }
 
 func TestHostVolume_HCLDecode(t *testing.T) {

command/volume_register.go

@@ -38,6 +38,10 @@ General Options:
 
 Register Options:
 
+  -id
+    Update a volume previously created with this ID prefix. Used for dynamic
+    host volumes only.
+
   -policy-override
     Sets the flag to force override any soft mandatory Sentinel policies. Used
     for dynamic host volumes only.
@@ -50,6 +54,7 @@ func (c *VolumeRegisterCommand) AutocompleteFlags() complete.Flags {
 	return mergeAutocompleteFlags(c.Meta.AutocompleteFlags(FlagSetClient),
 		complete.Flags{
 			"-policy-override": complete.PredictNothing,
+			"-id":              complete.PredictNothing,
 		})
 }
 
@@ -65,8 +70,10 @@ func (c *VolumeRegisterCommand) Name() string { return "volume register" }
 
 func (c *VolumeRegisterCommand) Run(args []string) int {
 	var override bool
+	var volID string
 	flags := c.Meta.FlagSet(c.Name(), FlagSetClient)
 	flags.BoolVar(&override, "policy-override", false, "override soft mandatory Sentinel policies")
+	flags.StringVar(&volID, "id", "", "update an existing dynamic host volume")
 	flags.Usage = func() { c.Ui.Output(c.Help()) }
 
 	if err := flags.Parse(args); err != nil {
@@ -118,7 +125,7 @@ func (c *VolumeRegisterCommand) Run(args []string) int {
 	case "csi":
 		return c.csiRegister(client, ast)
 	case "host":
-		return c.hostVolumeRegister(client, ast, override)
+		return c.hostVolumeRegister(client, ast, override, volID)
 	default:
 		c.Ui.Error(fmt.Sprintf("Error unknown volume type: %s", volType))
 		return 1

command/volume_register_host.go

@@ -10,7 +10,7 @@ import (
 	"github.com/hashicorp/nomad/api"
 )
 
-func (c *VolumeRegisterCommand) hostVolumeRegister(client *api.Client, ast *ast.File, override bool) int {
+func (c *VolumeRegisterCommand) hostVolumeRegister(client *api.Client, ast *ast.File, override bool, volID string) int {
 	vol, err := decodeHostVolume(ast)
 	if err != nil {
 		c.Ui.Error(fmt.Sprintf("Error decoding the volume definition: %s", err))
@@ -20,6 +20,27 @@ func (c *VolumeRegisterCommand) hostVolumeRegister(client *api.Client, ast *ast.
 		c.Ui.Error("Node ID is required for registering")
 		return 1
 	}
+	if volID != "" {
+		ns := c.namespace
+		if vol.Namespace != "" {
+			ns = vol.Namespace
+		}
+		stub, possible, err := getHostVolumeByPrefix(client, volID, ns)
+		if err != nil {
+			c.Ui.Error(fmt.Sprintf("Could not update existing volume: %s", err))
+			return 1
+		}
+		if len(possible) > 0 {
+			out, err := formatHostVolumes(possible, formatOpts{short: true})
+			if err != nil {
+				c.Ui.Error(fmt.Sprintf("Error formatting: %s", err))
+				return 1
+			}
+			c.Ui.Error(fmt.Sprintf("Prefix matched multiple volumes\n\n%s", out))
+			return 1
+		}
+		vol.ID = stub.ID
+	}
 
 	req := &api.HostVolumeRegisterRequest{
 		Volume:         vol,

command/volume_register_host_test.go

@@ -92,4 +92,11 @@ parameters {
 	got, _, err := client.HostVolumes().Get(id, &api.QueryOptions{Namespace: "prod"})
 	must.NoError(t, err)
 	must.NotNil(t, got)
+
+	// Verify we can update the volume without changes
+	args = []string{"-address", url, "-id", got.ID, file.Name()}
+	code = cmd.Run(args)
+	must.Eq(t, 0, code, must.Sprintf("got error: %s", ui.ErrorWriter.String()))
+	list, _, err := client.HostVolumes().List(nil, &api.QueryOptions{Namespace: "prod"})
+	must.Len(t, 1, list, must.Sprintf("new volume should not be registered on update"))
 }

command/volume_status_host.go

@@ -34,7 +34,7 @@ func (c *VolumeStatusCommand) hostVolumeStatus(client *api.Client, id, nodeID, n
 	// if an exact match is not found. note we can't use the shared getByPrefix
 	// helper here because the List API doesn't match the required signature
 
-	volStub, possible, err := c.getByPrefix(client, id)
+	volStub, possible, err := getHostVolumeByPrefix(client, id, c.namespace)
 	if err != nil {
 		c.Ui.Error(fmt.Sprintf("Error listing volumes: %s", err))
 		return 1
@@ -91,10 +91,10 @@ func (c *VolumeStatusCommand) listHostVolumes(client *api.Client, nodeID, nodePo
 	return 0
 }
 
-func (c *VolumeStatusCommand) getByPrefix(client *api.Client, prefix string) (*api.HostVolumeStub, []*api.HostVolumeStub, error) {
+func getHostVolumeByPrefix(client *api.Client, prefix, ns string) (*api.HostVolumeStub, []*api.HostVolumeStub, error) {
 	vols, _, err := client.HostVolumes().List(nil, &api.QueryOptions{
 		Prefix:    prefix,
-		Namespace: c.namespace,
+		Namespace: ns,
 	})
 
 	if err != nil {