google: Re-enable AppEngineTokenSource to be used from Managed VMs.
Fixes #152.
Change-Id: I757c011d3ac5dca8f80fb2119eda3adf8c178ca6
Reviewed-on: https://go-review.googlesource.com/14622
Reviewed-by: Andrew Gerrand <adg@golang.org>
diff --git a/google/appengine.go b/google/appengine.go
index 65dc347..8554221 100644
--- a/google/appengine.go
+++ b/google/appengine.go
@@ -14,6 +14,9 @@
"golang.org/x/oauth2"
)
+// Set at init time by appenginevm_hook.go. If true, we are on App Engine Managed VMs.
+var appengineVM bool
+
// Set at init time by appengine_hook.go. If nil, we're not on App Engine.
var appengineTokenFunc func(c context.Context, scopes ...string) (token string, expiry time.Time, err error)
diff --git a/google/appenginevm_hook.go b/google/appenginevm_hook.go
new file mode 100644
index 0000000..633611c
--- /dev/null
+++ b/google/appenginevm_hook.go
@@ -0,0 +1,14 @@
+// Copyright 2015 The oauth2 Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build appenginevm
+
+package google
+
+import "google.golang.org/appengine"
+
+func init() {
+ appengineVM = true
+ appengineTokenFunc = appengine.AccessToken
+}
diff --git a/google/default.go b/google/default.go
index 78f8089..66daeef 100644
--- a/google/default.go
+++ b/google/default.go
@@ -50,7 +50,8 @@
// On Windows, this is %APPDATA%/gcloud/application_default_credentials.json.
// On other systems, $HOME/.config/gcloud/application_default_credentials.json.
// 3. On Google App Engine it uses the appengine.AccessToken function.
-// 4. On Google Compute Engine, it fetches credentials from the metadata server.
+// 4. On Google Compute Engine and Google App Engine Managed VMs, it fetches
+// credentials from the metadata server.
// (In this final case any provided scopes are ignored.)
//
// For more details, see:
@@ -84,7 +85,7 @@
}
// Third, if we're on Google App Engine use those credentials.
- if appengineTokenFunc != nil {
+ if appengineTokenFunc != nil && !appengineVM {
return AppEngineTokenSource(ctx, scope...), nil
}
