feat: Inital commit

2025-07-26 05:58:59 +00:00
commit 753d1c60ea
1849 changed files with 830533 additions and 0 deletions
@@ -0,0 +1,69 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package detect is used find information from the environment.
+package detect
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"os"
+
+	"golang.org/x/oauth2/google"
+	"google.golang.org/api/option"
+	"google.golang.org/api/transport"
+)
+
+const (
+	// ProjectIDSentinel is the value that users should pass for the project ID
+	// to enable detection.
+	ProjectIDSentinel = "*detect-project-id*"
+	envProjectID      = "GOOGLE_CLOUD_PROJECT"
+)
+
+var (
+	adcLookupFunc func(context.Context, ...option.ClientOption) (*google.Credentials, error) = transport.Creds
+	envLookupFunc func(string) string                                                        = os.Getenv
+)
+
+// ProjectID tries to detect the project ID from the environment if the sentinel
+// value, "*detect-project-id*", is sent. It looks in the following order:
+//  1. GOOGLE_CLOUD_PROJECT envvar
+//  2. ADC creds.ProjectID
+//  3. A static value if the environment is emulated.
+func ProjectID(ctx context.Context, projectID, emulatorEnvVar string, opts ...option.ClientOption) (string, error) {
+	if projectID != ProjectIDSentinel {
+		return projectID, nil
+	}
+	// 1. Try a well known environment variable
+	if id := envLookupFunc(envProjectID); id != "" {
+		return id, nil
+	}
+	// 2. Try ADC
+	creds, err := adcLookupFunc(ctx, opts...)
+	if err != nil {
+		return "", fmt.Errorf("fetching creds: %v", err)
+	}
+	// 3. If ADC does not work, and the environment is emulated, return a const value.
+	if creds.ProjectID == "" && emulatorEnvVar != "" && envLookupFunc(emulatorEnvVar) != "" {
+		return "emulated-project", nil
+	}
+	// 4. If 1-3 don't work, error out
+	if creds.ProjectID == "" {
+		return "", errors.New("unable to detect projectID, please refer to docs for DetectProjectID")
+	}
+	// Success from ADC
+	return creds.ProjectID, nil
+}