add contentType metadata support for GCP bucket operations (#3998)

Signed-off-by: MyMirelHub <[email protected]>

Author: MyMirelHub

bindings/gcp/bucket/bucket.go

@@ -47,8 +47,9 @@ const (
 	metadataEncodeBase64 = "encodeBase64"
 	metadataSignTTL      = "signTTL"
 
-	metadataKey = "key"
-	maxResults  = 1000
+	metadataContentType = "contentType"
+	metadataKey         = "key"
+	maxResults          = 1000
 
 	metadataKeyBC    = "name"
 	signOperation    = "sign"
@@ -77,6 +78,7 @@ type gcpMetadata struct {
 	TokenURI            string `json:"token_uri" mapstructure:"tokenURI" mdignore:"true" mapstructurealiases:"token_uri"`
 	AuthProviderCertURL string `json:"auth_provider_x509_cert_url" mapstructure:"authProviderX509CertURL" mdignore:"true" mapstructurealiases:"auth_provider_x509_cert_url"`
 	ClientCertURL       string `json:"client_x509_cert_url" mapstructure:"clientX509CertURL" mdignore:"true" mapstructurealiases:"client_x509_cert_url"`
+	ContentType         string `json:"contentType,omitempty" mapstructure:"contentType"`
 
 	Bucket       string `json:"bucket" mapstructure:"bucket"`
 	DecodeBase64 bool   `json:"decodeBase64,string" mapstructure:"decodeBase64"`
@@ -233,6 +235,12 @@ func (g *GCPStorage) create(ctx context.Context, req *bindings.InvokeRequest) (*
 	}
 
 	h := g.client.Bucket(g.metadata.Bucket).Object(name).NewWriter(ctx)
+
+	// Set content type if provided
+	if metadata.ContentType != "" {
+		h.ContentType = metadata.ContentType
+	}
+
 	// Cannot do `defer h.Close()` as Close() will flush the bytes and need to have error handling.
 	if _, err = io.Copy(h, r); err != nil {
 		cerr := h.Close()
@@ -378,9 +386,15 @@ func (metadata gcpMetadata) mergeWithRequestMetadata(req *bindings.InvokeRequest
 	if val, ok := req.Metadata[metadataEncodeBase64]; ok && val != "" {
 		merged.EncodeBase64 = strings.IsTruthy(val)
 	}
+
 	if val, ok := req.Metadata[metadataSignTTL]; ok && val != "" {
 		merged.SignTTL = val
 	}
+
+	if val, ok := req.Metadata[metadataContentType]; ok && val != "" {
+		merged.ContentType = val
+	}
+
 	return merged, nil
 }
 

bindings/gcp/bucket/bucket_test.go

@@ -233,6 +233,42 @@ func TestMergeWithRequestMetadata(t *testing.T) {
 		assert.NotNil(t, mergedMeta)
 		assert.False(t, mergedMeta.EncodeBase64)
 	})
+
+	t.Run("Has merged contentType metadata", func(t *testing.T) {
+		m := bindings.Metadata{}
+		m.Properties = map[string]string{
+			"bucket":      "my_bucket",
+			"projectID":   "my_project_id",
+			"contentType": "text/plain",
+		}
+		gs := GCPStorage{logger: logger.NewLogger("test")}
+		meta, err := gs.parseMetadata(m)
+		require.NoError(t, err)
+		assert.Equal(t, "text/plain", meta.ContentType)
+
+		// Empty request doesn't override
+		request := bindings.InvokeRequest{}
+		request.Metadata = map[string]string{}
+		mergedMeta, err := meta.mergeWithRequestMetadata(&request)
+		require.NoError(t, err)
+		assert.Equal(t, "text/plain", mergedMeta.ContentType)
+
+		// Request overrides component
+		request.Metadata = map[string]string{
+			"contentType": "text/csv",
+		}
+		mergedMeta, err = meta.mergeWithRequestMetadata(&request)
+		require.NoError(t, err)
+		assert.Equal(t, "text/csv", mergedMeta.ContentType)
+
+		// Empty string doesn't override
+		request.Metadata = map[string]string{
+			"contentType": "",
+		}
+		mergedMeta, err = meta.mergeWithRequestMetadata(&request)
+		require.NoError(t, err)
+		assert.Equal(t, "text/plain", mergedMeta.ContentType)
+	})
 }
 
 func TestInit(t *testing.T) {

bindings/gcp/bucket/metadata.yaml

@@ -44,4 +44,12 @@ metadata:
     description: |
       Configuration to encode base64 file content before return the content. 
       (In case of saving a file with binary content).
-    example: '"true, false"'
+    example: '"true, false"'
+  - name: contentType
+    type: string
+    required: false
+    description: |
+      The MIME type of the object being stored. If not specified, GCS will attempt to 
+      auto-detect the type, which may default to application/octet-stream or text/plain.
+      Common values include text/csv, application/json, image/png, etc.
+    example: '"text/csv", "application/json"'