1 // Copyright 2014 The Go Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
4 5 package google
6 7 import (
8 "context"
9 "log"
10 "sync"
11 12 "golang.org/x/oauth2"
13 )
14 15 var logOnce sync.Once // only spam about deprecation once
16 17 // AppEngineTokenSource returns a token source that fetches tokens from either
18 // the current application's service account or from the metadata server,
19 // depending on the App Engine environment. See below for environment-specific
20 // details. If you are implementing a 3-legged OAuth 2.0 flow on App Engine that
21 // involves user accounts, see oauth2.Config instead.
22 //
23 // The current version of this library requires at least Go 1.17 to build,
24 // so first generation App Engine runtimes (<= Go 1.9) are unsupported.
25 // Previously, on first generation App Engine runtimes, AppEngineTokenSource
26 // returned a token source that fetches tokens issued to the
27 // current App Engine application's service account. The provided context must have
28 // come from appengine.NewContext.
29 //
30 // Second generation App Engine runtimes (>= Go 1.11) and App Engine flexible:
31 // AppEngineTokenSource is DEPRECATED on second generation runtimes and on the
32 // flexible environment. It delegates to ComputeTokenSource, and the provided
33 // context and scopes are not used. Please use DefaultTokenSource (or ComputeTokenSource,
34 // which DefaultTokenSource will use in this case) instead.
35 func AppEngineTokenSource(ctx context.Context, scope ...string) oauth2.TokenSource {
36 logOnce.Do(func() {
37 log.Print("google: AppEngineTokenSource is deprecated on App Engine standard second generation runtimes (>= Go 1.11) and App Engine flexible. Please use DefaultTokenSource or ComputeTokenSource.")
38 })
39 return ComputeTokenSource("")
40 }
41