Support mounting volumes to containers

kyaml/kio/filters/container.go

@@ -134,6 +134,9 @@ type ContainerFilter struct {
 	// Network is the container network to use.
 	Network string `yaml:"network,omitempty"`
 
+	// Volumes are the directories to mount as container volumes.
+	Volumes []string `yaml:"volumes,omitempty"`
+
 	// StorageMounts is a list of storage options that the container will have mounted.
 	StorageMounts []StorageMount
 
@@ -335,6 +338,11 @@ func (c *ContainerFilter) getArgs() []string {
 		args = append(args, "--mount", storageMount.String())
 	}
 
+	// export volumes to the container
+	for _, volume := range c.Volumes {
+		args = append(args, "--volume", volume)
+	}
+
 	// export the local environment vars to the container
 	for _, pair := range os.Environ() {
 		tokens := strings.Split(pair, "=")

kyaml/kio/filters/container_test.go

@@ -141,6 +141,87 @@ metadata:
 	assert.Equal(t, expected, cmd.Args)
 }
 
+func TestFilter_command_volume(t *testing.T) {
+	cfg, err := yaml.Parse(`apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: foo
+`)
+	if !assert.NoError(t, err) {
+		return
+	}
+	instance := &ContainerFilter{
+		Image:   "example.com:version",
+		Volumes: []string{"/host-src:/container-dest:ro"},
+		Config:  cfg,
+	}
+	cmd, err := instance.getCommand()
+	if !assert.NoError(t, err) {
+		return
+	}
+
+	expected := []string{
+		"docker", "run",
+		"--rm",
+		"-i", "-a", "STDIN", "-a", "STDOUT", "-a", "STDERR",
+		"--network", "none",
+		"--user", "nobody",
+		"--security-opt=no-new-privileges",
+		"--volume", "/host-src:/container-dest:ro",
+	}
+	for _, e := range os.Environ() {
+		// the process env
+		tokens := strings.Split(e, "=")
+		if tokens[0] == "" {
+			continue
+		}
+		expected = append(expected, "-e", tokens[0])
+	}
+	expected = append(expected, "example.com:version")
+	assert.Equal(t, expected, cmd.Args)
+}
+
+func TestFilter_command_volumes(t *testing.T) {
+	cfg, err := yaml.Parse(`apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: foo
+`)
+	if !assert.NoError(t, err) {
+		return
+	}
+	instance := &ContainerFilter{
+		Image:   "example.com:version",
+		Volumes: []string{"/host-src1:/container-dest1:ro", "/host-src2:/container-dest2:rw"},
+		Config:  cfg,
+	}
+	cmd, err := instance.getCommand()
+	if !assert.NoError(t, err) {
+		return
+	}
+
+	expected := []string{
+		"docker", "run",
+		"--rm",
+		"-i", "-a", "STDIN", "-a", "STDOUT", "-a", "STDERR",
+		"--network", "none",
+		"--user", "nobody",
+		"--security-opt=no-new-privileges",
+		"--volume", "/host-src1:/container-dest1:ro",
+		"--volume", "/host-src2:/container-dest2:rw",
+	}
+	for _, e := range os.Environ() {
+		// the process env
+		tokens := strings.Split(e, "=")
+		if tokens[0] == "" {
+			continue
+		}
+		expected = append(expected, "-e", tokens[0])
+	}
+	expected = append(expected, "example.com:version")
+	assert.Equal(t, expected, cmd.Args)
+}
+
 func TestFilter_Filter(t *testing.T) {
 	cfg, err := yaml.Parse(`apiVersion: apps/v1
 kind: Deployment
@@ -355,6 +436,70 @@ container:
 `,
 		},
 
+		{
+			name: "volume",
+			resource: `
+apiVersion: v1beta1
+kind: Example
+metadata:
+  annotations:
+    config.kubernetes.io/function: |-
+      container:
+        image: foo:v1.0.0
+        volumes: ["/host-src:/container-dest:ro"]
+`,
+			expectedFn: `
+container:
+    image: foo:v1.0.0
+    volumes:
+      - /host-src:/container-dest:ro
+`,
+		},
+
+		{
+			name: "volumes as array",
+			resource: `
+apiVersion: v1beta1
+kind: Example
+metadata:
+  annotations:
+    config.kubernetes.io/function: |-
+      container:
+        image: foo:v1.0.0
+        volumes: ["/host-src1:/container-dest1:ro", "/host-src2:/container-dest2:rw"]
+`,
+			expectedFn: `
+container:
+    image: foo:v1.0.0
+    volumes:
+      - /host-src1:/container-dest1:ro
+      - /host-src2:/container-dest2:rw
+`,
+		},
+
+		{
+			name: "volumes as list",
+			resource: `
+apiVersion: v1beta1
+kind: Example
+metadata:
+  annotations:
+    config.kubernetes.io/function: |-
+      container:
+        image: foo:v1.0.0
+        volumes:
+        - "/host-src1:/container-dest1:ro"
+        - "/host-src2:/container-dest2:rw"
+`,
+			expectedFn: `
+container:
+    image: foo:v1.0.0
+    volumes:
+      - /host-src1:/container-dest1:ro
+      - /host-src2:/container-dest2:rw
+`,
+		},
+
 		{
 			name: "path",
 			resource: `
@@ -516,6 +661,76 @@ metadata:
 	}
 }
 
+func Test_GetContainerVolumeRequired(t *testing.T) {
+	tests := []struct {
+		input   string
+		volumes []string
+	}{
+		{
+			input: `apiVersion: v1
+kind: Foo
+metadata:
+  name: foo
+  configFn:
+    container:
+      image: gcr.io/kustomize-functions/example-tshirt:v0.1.0
+      volumes: [ /host-src:/container-dest:ro ]
+`,
+			volumes: []string{"/host-src:/container-dest:ro"},
+		},
+		{
+
+			input: `apiVersion: v1
+kind: Foo
+metadata:
+  name: foo
+  configFn:
+    container:
+      image: gcr.io/kustomize-functions/example-tshirt:v0.1.0
+`,
+			volumes: []string(nil),
+		},
+		{
+			input: `apiVersion: v1
+kind: Foo
+metadata:
+  name: foo
+  annotations:
+    config.kubernetes.io/function: |
+      container:
+        image: gcr.io/kustomize-functions/example-tshirt:v0.1.0
+        volumes: [ "/host-src1:/container-dest1:ro", "/host-src2:/container-dest2:rw" ]
+`,
+			volumes: []string{"/host-src1:/container-dest1:ro", "/host-src2:/container-dest2:rw"},
+		},
+		{
+			input: `apiVersion: v1
+kind: Foo
+metadata:
+  name: foo
+  annotations:
+    config.kubernetes.io/function: |
+      container:
+        image: gcr.io/kustomize-functions/example-tshirt:v0.1.0
+        volumes:
+          - /host-src1:/container-dest1:ro
+          - /host-src2:/container-dest2:rw
+`,
+			volumes: []string{"/host-src1:/container-dest1:ro", "/host-src2:/container-dest2:rw"},
+		},
+	}
+
+	for _, tc := range tests {
+		cfg, err := yaml.Parse(tc.input)
+		if !assert.NoError(t, err) {
+			return
+		}
+
+		fn := GetFunctionSpec(cfg)
+		assert.Equal(t, tc.volumes, fn.Container.Volumes)
+	}
+}
+
 func TestFilter_Filter_defaultNaming(t *testing.T) {
 	cfg, err := yaml.Parse(`apiVersion: apps/v1
 kind: Deployment

kyaml/kio/filters/functiontypes.go

@@ -28,6 +28,9 @@ type FunctionSpec struct {
 
 	// Starlark is the spec for running a function as a starlark script
 	Starlark StarlarkSpec `json:"starlark,omitempty" yaml:"starlark,omitempty"`
+
+	// Volumes are the directories to mount as container volumes
+	Volumes []string `json:"volumes,omitempty" yaml:"volumes,omitempty"`
 }
 
 // ContainerSpec defines a spec for running a function as a container
@@ -37,6 +40,9 @@ type ContainerSpec struct {
 
 	// Network defines network specific configuration
 	Network ContainerNetwork `json:"network,omitempty" yaml:"network,omitempty"`
+
+	// Volumes are the directories to mount as container volumes
+	Volumes []string `json:"volumes,omitempty" yaml:"volumes,omitempty"`
 }
 
 // ContainerNetwork
@@ -68,6 +74,7 @@ func GetFunctionSpec(n *yaml.RNode) *FunctionSpec {
 	path := meta.Annotations[kioutil.PathAnnotation]
 	if fn := getFunctionSpecFromAnnotation(n, meta); fn != nil {
 		fn.Network = ""
+		fn.Volumes = []string{}
 		fn.Path = path
 		return fn
 	}

kyaml/runfn/runfn.go

@@ -51,6 +51,10 @@ type RunFns struct {
 	// NetworkName is the name of the docker network to use for the container
 	NetworkName string
 
+	// Volumes Volumes allows directories to be specified outside the configuration
+	// directory.
+	Volumes []string
+
 	// Output can be set to write the result to Output rather than back to the directory
 	Output io.Writer
 
@@ -133,6 +137,13 @@ func (r RunFns) getFilters(nodes []*yaml.RNode) ([]kio.Filter, error) {
 	}
 	fltrs = append(fltrs, f...)
 
+	// directories from volumes specified on the struct
+	f, err = r.getDirectoriesFromVolumes()
+	if err != nil {
+		return nil, err
+	}
+	fltrs = append(fltrs, f...)
+
 	// explicit fns specified on the struct
 	f, err = r.getFunctionsFromFunctions()
 	if err != nil {
@@ -196,6 +207,24 @@ func (r RunFns) getFunctionsFromFunctionPaths() ([]kio.Filter, error) {
 	return r.getFunctionFilters(true, buff.Nodes...)
 }
 
+// getDirectoriesFromVolumes returns the set of directories read from r.Volumes
+// as a slice of Filters
+func (r RunFns) getDirectoriesFromVolumes() ([]kio.Filter, error) {
+	buff := &kio.PackageBuffer{}
+	for i := range r.Volumes {
+		err := kio.Pipeline{
+			Inputs: []kio.Reader{
+				kio.LocalPackageReader{PackagePath: r.Volumes[i]},
+			},
+			Outputs: []kio.Writer{buff},
+		}.Execute()
+		if err != nil {
+			return nil, err
+		}
+	}
+	return r.getFunctionFilters(true, buff.Nodes...)
+}
+
 // getFunctionsFromFunctions returns the set of explicitly provided functions as
 // Filters
 func (r RunFns) getFunctionsFromFunctions() ([]kio.Filter, error) {

kyaml/runfn/runfn_test.go

@@ -140,6 +140,16 @@ func TestRunFns_Execute__initDefault(t *testing.T) {
 				FunctionPaths:        []string{"foo"},
 			},
 		},
+		{
+			name:     "explicit directories in volumes",
+			instance: RunFns{Volumes: []string{"vol"}},
+			expected: RunFns{
+				Output:               os.Stdout,
+				Input:                os.Stdin,
+				NoFunctionsFromInput: getFalse(),
+				Volumes:              []string{"vol"},
+			},
+		},
 	}
 	for i := range tests {
 		tt := tests[i]