bake: add annotations field

Signed-off-by: Justin Chadwell <me@jedevc.com>

bake/bake.go

@@ -589,6 +589,7 @@ type Target struct {
 	// Inherits is the only field that cannot be overridden with --set
 	Inherits []string `json:"inherits,omitempty" hcl:"inherits,optional" cty:"inherits"`
 
+	Annotations      []string           `json:"annotations,omitempty" hcl:"annotations,optional" cty:"annotations"`
 	Attest           []string           `json:"attest,omitempty" hcl:"attest,optional" cty:"attest"`
 	Context          *string            `json:"context,omitempty" hcl:"context,optional" cty:"context"`
 	Contexts         map[string]string  `json:"contexts,omitempty" hcl:"contexts,optional" cty:"contexts"`
@@ -620,6 +621,7 @@ var _ hclparser.WithEvalContexts = &Group{}
 var _ hclparser.WithGetName = &Group{}
 
 func (t *Target) normalize() {
+	t.Annotations = removeDupes(t.Annotations)
 	t.Attest = removeAttestDupes(t.Attest)
 	t.Tags = removeDupes(t.Tags)
 	t.Secrets = removeDupes(t.Secrets)
@@ -680,6 +682,9 @@ func (t *Target) Merge(t2 *Target) {
 	if t2.Target != nil {
 		t.Target = t2.Target
 	}
+	if t2.Annotations != nil { // merge
+		t.Annotations = append(t.Annotations, t2.Annotations...)
+	}
 	if t2.Attest != nil { // merge
 		t.Attest = append(t.Attest, t2.Attest...)
 		t.Attest = removeAttestDupes(t.Attest)
@@ -766,6 +771,8 @@ func (t *Target) AddOverrides(overrides map[string]Override) error {
 			t.Platforms = o.ArrValue
 		case "output":
 			t.Outputs = o.ArrValue
+		case "annotations":
+			t.Annotations = append(t.Annotations, o.ArrValue...)
 		case "attest":
 			t.Attest = append(t.Attest, o.ArrValue...)
 		case "no-cache":
@@ -1164,6 +1171,16 @@ func toBuildOpt(t *Target, inp *Input) (*build.Options, error) {
 		return nil, err
 	}
 
+	annotations, err := buildflags.ParseAnnotations(t.Annotations)
+	if err != nil {
+		return nil, err
+	}
+	for _, e := range bo.Exports {
+		for k, v := range annotations {
+			e.Attrs[k.String()] = v
+		}
+	}
+
 	attests, err := buildflags.ParseAttests(t.Attest)
 	if err != nil {
 		return nil, err

bake/bake_test.go

@@ -1460,3 +1460,31 @@ func TestAttestDuplicates(t *testing.T) {
 		"provenance": ptrstr("type=provenance,mode=max"),
 	}, opts["default"].Attests)
 }
+
+func TestAnnotations(t *testing.T) {
+	fp := File{
+		Name: "docker-bake.hcl",
+		Data: []byte(
+			`target "app" {
+				output = ["type=image,name=foo"]
+				annotations = ["manifest[linux/amd64]:foo=bar"]
+			}`),
+	}
+	ctx := context.TODO()
+	m, g, err := ReadTargets(ctx, []File{fp}, []string{"app"}, nil, nil)
+	require.NoError(t, err)
+
+	bo, err := TargetsToBuildOpt(m, &Input{})
+	require.NoError(t, err)
+
+	require.Equal(t, 1, len(g))
+	require.Equal(t, []string{"app"}, g["default"].Targets)
+
+	require.Equal(t, 1, len(m))
+	require.Contains(t, m, "app")
+	require.Equal(t, "type=image,name=foo", m["app"].Outputs[0])
+	require.Equal(t, "manifest[linux/amd64]:foo=bar", m["app"].Annotations[0])
+
+	require.Len(t, bo["app"].Exports, 1)
+	require.Equal(t, "bar", bo["app"].Exports[0].Attrs["annotation-manifest[linux/amd64].foo"])
+}

docs/bake-reference.md

@@ -115,6 +115,7 @@ The following table shows the complete list of attributes that you can assign to
 | Name                                            | Type    | Description                                                          |
 | ----------------------------------------------- | ------- | -------------------------------------------------------------------- |
 | [`args`](#targetargs)                           | Map     | Build arguments                                                      |
+| [`annotations`](#targetannotations)             | List    | Exporter annotations                                                 |
 | [`attest`](#targetattest)                       | List    | Build attestations                                                   |
 | [`cache-from`](#targetcache-from)               | List    | External cache sources                                               |
 | [`cache-to`](#targetcache-to)                   | List    | External cache destinations                                          |
@@ -171,6 +172,26 @@ target "db" {
 }
 ```
 
+### `target.annotations`
+
+The `annotations` attribute is a shortcut to allow you to easily set a list of
+annotations on the target.
+
+```hcl
+target "default" {
+  output = ["type=image,name=foo"]
+  annotations = ["key=value"]
+}
+```
+
+is the same as
+
+```hcl
+target "default" {
+  output = ["type=image,name=foo,annotation.key=value"]
+}
+```
+
 ### `target.attest`
 
 The `attest` attribute lets you apply [build attestations][attestations] to the target.