Add podman volume create --ignore

This ignores the create request if the named volume already exists. It is very useful when scripting stuff. Signed-off-by: Alexander Larsson <[email protected]>
containers · Oct 24, 2022 · 734c435 · 734c435
1 parent a77ac5b
commit 734c435
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Showing 9 changed files with 78 additions and 12 deletions.
diff --git a/cmd/podman/volumes/create.go b/cmd/podman/volumes/create.go
@@ -30,8 +30,9 @@ var (
 var (
 	createOpts = entities.VolumeCreateOptions{}
 	opts       = struct {
-		Label []string
-		Opts  []string
+		Label  []string
+		Opts   []string
+		Ignore bool
 	}{}
 )
 
@@ -53,6 +54,9 @@ func init() {
 	optFlagName := "opt"
 	flags.StringArrayVarP(&opts.Opts, optFlagName, "o", []string{}, "Set driver specific options (default [])")
 	_ = createCommand.RegisterFlagCompletionFunc(optFlagName, completion.AutocompleteNone)
+
+	ignoreFlagName := "ignore"
+	flags.BoolVar(&opts.Ignore, ignoreFlagName, false, "Don't fail if volume already exists")
 }
 
 func create(cmd *cobra.Command, args []string) error {
@@ -62,6 +66,9 @@ func create(cmd *cobra.Command, args []string) error {
 	if len(args) > 0 {
 		createOpts.Name = args[0]
 	}
+
+	createOpts.IgnoreIfExists = opts.Ignore
+
 	createOpts.Label, err = parse.GetAllLabels([]string{}, opts.Label)
 	if err != nil {
 		return fmt.Errorf("unable to process labels: %w", err)

diff --git a/docs/source/markdown/podman-volume-create.1.md b/docs/source/markdown/podman-volume-create.1.md
@@ -29,6 +29,10 @@ Such plugins must be defined in the **volume_plugins** section of the **[contain
 
 Print usage statement
 
+#### **--ignore**
+
+Don't fail if the named volume already exists, instead just print the name. Note that the new options are not applied to the existing volume.
+
 #### **--label**, **-l**=*label*
 
 Set metadata for a volume (e.g., --label mykey=value).

diff --git a/libpod/options.go b/libpod/options.go
@@ -1551,6 +1551,17 @@ func WithCreateWorkingDir() CtrCreateOption {
 
 // Volume Creation Options
 
+func WithVolumeIgnoreIfExist() VolumeCreateOption {
+	return func(volume *Volume) error {
+		if volume.valid {
+			return define.ErrVolumeFinalized
+		}
+		volume.ignoreIfExists = true
+
+		return nil
+	}
+}
+
 // WithVolumeName sets the name of the volume.
 func WithVolumeName(name string) VolumeCreateOption {
 	return func(volume *Volume) error {

diff --git a/libpod/runtime_volume_common.go b/libpod/runtime_volume_common.go
@@ -53,12 +53,14 @@ func (r *Runtime) newVolume(ctx context.Context, noCreatePluginVolume bool, opti
 	volume.config.CreatedTime = time.Now()
 
 	// Check if volume with given name exists.
-	exists, err := r.state.HasVolume(volume.config.Name)
-	if err != nil {
-		return nil, fmt.Errorf("checking if volume with name %s exists: %w", volume.config.Name, err)
-	}
-	if exists {
-		return nil, fmt.Errorf("volume with name %s already exists: %w", volume.config.Name, define.ErrVolumeExists)
+	if !volume.ignoreIfExists {
+		exists, err := r.state.HasVolume(volume.config.Name)
+		if err != nil {
+			return nil, fmt.Errorf("checking if volume with name %s exists: %w", volume.config.Name, err)
+		}
+		if exists {
+			return nil, fmt.Errorf("volume with name %s already exists: %w", volume.config.Name, define.ErrVolumeExists)
+		}
 	}
 
 	// Plugin can be nil if driver is local, but that's OK - superfluous
@@ -209,6 +211,13 @@ func (r *Runtime) newVolume(ctx context.Context, noCreatePluginVolume bool, opti
 
 	// Add the volume to state
 	if err := r.state.AddVolume(volume); err != nil {
+		if volume.ignoreIfExists && errors.Is(err, define.ErrVolumeExists) {
+			existingVolume, err := r.state.Volume(volume.config.Name)
+			if err != nil {
+				return nil, fmt.Errorf("reading volume from state: %w", err)
+			}
+			return existingVolume, nil
+		}
 		return nil, fmt.Errorf("adding volume to state: %w", err)
 	}
 	defer volume.newVolumeEvent(events.Create)

diff --git a/libpod/volume.go b/libpod/volume.go
@@ -17,10 +17,11 @@ type Volume struct {
 	config *VolumeConfig
 	state  *VolumeState
 
-	valid   bool
-	plugin  *plugin.VolumePlugin
-	runtime *Runtime
-	lock    lock.Locker
+	ignoreIfExists bool
+	valid          bool
+	plugin         *plugin.VolumePlugin
+	runtime        *Runtime
+	lock           lock.Locker
 }
 
 // VolumeConfig holds the volume's immutable configuration.

diff --git a/pkg/api/handlers/libpod/volumes.go b/pkg/api/handlers/libpod/volumes.go
@@ -70,6 +70,11 @@ func CreateVolume(w http.ResponseWriter, r *http.Request) {
 		}
 		volumeOptions = append(volumeOptions, parsedOptions...)
 	}
+
+	if input.IgnoreIfExists {
+		volumeOptions = append(volumeOptions, libpod.WithVolumeIgnoreIfExist())
+	}
+
 	vol, err := runtime.NewVolume(r.Context(), volumeOptions...)
 	if err != nil {
 		utils.InternalServerError(w, err)

diff --git a/pkg/domain/entities/volumes.go b/pkg/domain/entities/volumes.go
@@ -19,6 +19,8 @@ type VolumeCreateOptions struct {
 	Labels map[string]string `schema:"labels"`
 	// Mapping of driver options and values.
 	Options map[string]string `schema:"opts"`
+	// Ignore existing volumes
+	IgnoreIfExists bool `schema:"ignoreIfExist"`
 }
 
 type VolumeConfigResponse struct {

diff --git a/pkg/domain/infra/abi/volumes.go b/pkg/domain/infra/abi/volumes.go
@@ -33,6 +33,11 @@ func (ic *ContainerEngine) VolumeCreate(ctx context.Context, opts entities.Volum
 		}
 		volumeOptions = append(volumeOptions, parsedOptions...)
 	}
+
+	if opts.IgnoreIfExists {
+		volumeOptions = append(volumeOptions, libpod.WithVolumeIgnoreIfExist())
+	}
+
 	vol, err := ic.Libpod.NewVolume(ctx, volumeOptions...)
 	if err != nil {
 		return nil, err

diff --git a/test/e2e/volume_create_test.go b/test/e2e/volume_create_test.go
@@ -58,6 +58,28 @@ var _ = Describe("Podman volume create", func() {
 		Expect(check.OutputToStringArray()).To(HaveLen(1))
 	})
 
+	It("podman create volume with existing name fails", func() {
+		session := podmanTest.Podman([]string{"volume", "create", "myvol"})
+		session.WaitWithDefaultTimeout()
+		Expect(session).Should(Exit(0))
+
+		session = podmanTest.Podman([]string{"volume", "create", "myvol"})
+		session.WaitWithDefaultTimeout()
+		Expect(session).To(ExitWithError())
+	})
+
+	It("podman create volume --ignore", func() {
+		session := podmanTest.Podman([]string{"volume", "create", "myvol"})
+		session.WaitWithDefaultTimeout()
+		volName := session.OutputToString()
+		Expect(session).Should(Exit(0))
+
+		session = podmanTest.Podman([]string{"volume", "create", "--ignore", "myvol"})
+		session.WaitWithDefaultTimeout()
+		Expect(session).Should(Exit(0))
+		Expect(session.OutputToString()).To(Equal(volName))
+	})
+
 	It("podman create and export volume", func() {
 		if podmanTest.RemoteTest {
 			Skip("Volume export check does not work with a remote client")