compile: adds metadata field to .manifest (#4306)

Fixes: #4289

Signed-off-by: marensws <msws@live.no>

bundle/bundle.go

@@ -180,7 +180,7 @@ func (m Manifest) Copy() Manifest {
 
 func (m Manifest) String() string {
 	m.Init()
-	return fmt.Sprintf("<revision: %q, roots: %v, wasm: %+v>", m.Revision, *m.Roots, m.WasmResolvers)
+	return fmt.Sprintf("<revision: %q, roots: %v, wasm: %+v, metadata: %+v>", m.Revision, *m.Roots, m.WasmResolvers, m.Metadata)
 }
 
 func (m Manifest) rootSet() stringSet {

compile/compile.go

@@ -75,6 +75,7 @@ type Compiler struct {
 	bvc               *bundle.VerificationConfig // represents the key configuration used to verify a signed bundle
 	bsc               *bundle.SigningConfig      // represents the key configuration used to generate a signed bundle
 	keyID             string                     // represents the name of the default key used to verify a signed bundle
+	metadata          *map[string]interface{}    // represents additional data included in .manifest file
 }
 
 // New returns a new compiler instance that can be invoked.
@@ -180,6 +181,12 @@ func (c *Compiler) WithCapabilities(capabilities *ast.Capabilities) *Compiler {
 	return c
 }
 
+//WithMetadata sets the additional data to be included in .manifest
+func (c *Compiler) WithMetadata(metadata *map[string]interface{}) *Compiler {
+	c.metadata = metadata
+	return c
+}
+
 // Build compiles and links the input files and outputs a bundle to the writer.
 func (c *Compiler) Build(ctx context.Context) error {
 
@@ -223,6 +230,10 @@ func (c *Compiler) Build(ctx context.Context) error {
 		c.bundle.Manifest.Revision = *c.revision
 	}
 
+	if c.metadata != nil {
+		c.bundle.Manifest.Metadata = *c.metadata
+	}
+
 	if err := c.bundle.FormatModules(false); err != nil {
 		return err
 	}

compile/compile_test.go

@@ -703,6 +703,28 @@ func TestCompilerSetRevision(t *testing.T) {
 	})
 }
 
+func TestCompilerSetMetadata(t *testing.T) {
+	files := map[string]string{
+		"test.rego": `package test
+
+		p = true`,
+	}
+
+	test.WithTempFS(files, func(root string) {
+		metadata := map[string]interface{}{"OPA version": "0.36.1"}
+		compiler := New().WithPaths(root).WithMetadata(&metadata)
+
+		err := compiler.Build(context.Background())
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if compiler.bundle.Manifest.Metadata["OPA version"] != "0.36.1" {
+			t.Fatal("expected metadata to be set but got:", compiler.bundle.Manifest)
+		}
+	})
+}
+
 func TestCompilerOutput(t *testing.T) {
 	// NOTE(tsandall): must use format package here because the compiler formats.
 	files := map[string]string{