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
5package google
6
7import (
8	"context"
9	"time"
10
11	"golang.org/x/oauth2"
12)
13
14// Set at init time by appengine_gen1.go. If nil, we're not on App Engine standard first generation (<= Go 1.9) or App Engine flexible.
15var appengineTokenFunc func(c context.Context, scopes ...string) (token string, expiry time.Time, err error)
16
17// Set at init time by appengine_gen1.go. If nil, we're not on App Engine standard first generation (<= Go 1.9) or App Engine flexible.
18var appengineAppIDFunc func(c context.Context) string
19
20// AppEngineTokenSource returns a token source that fetches tokens from either
21// the current application's service account or from the metadata server,
22// depending on the App Engine environment. See below for environment-specific
23// details. If you are implementing a 3-legged OAuth 2.0 flow on App Engine that
24// involves user accounts, see oauth2.Config instead.
25//
26// First generation App Engine runtimes (<= Go 1.9):
27// AppEngineTokenSource returns a token source that fetches tokens issued to the
28// current App Engine application's service account. The provided context must have
29// come from appengine.NewContext.
30//
31// Second generation App Engine runtimes (>= Go 1.11) and App Engine flexible:
32// AppEngineTokenSource is DEPRECATED on second generation runtimes and on the
33// flexible environment. It delegates to ComputeTokenSource, and the provided
34// context and scopes are not used. Please use DefaultTokenSource (or ComputeTokenSource,
35// which DefaultTokenSource will use in this case) instead.
36func AppEngineTokenSource(ctx context.Context, scope ...string) oauth2.TokenSource {
37	return appEngineTokenSource(ctx, scope...)
38}
39