server/auth: Add TokenSource call.

common/auth/auth.go

 // Copyright 2015 The LUCI Authors. All rights reserved.
 // Use of this source code is governed under the Apache License, Version 2.0
 // that can be found in the LICENSE file.
 
 // Package auth implements an opinionated wrapper around OAuth2.
 //
 // It hides configurability of base oauth2 library and instead makes a
 // predefined set of choices regarding where the credentials should be stored,
 // how they should be cached and how OAuth2 flow should be invoked.
 //
@@ skipping 206 matching lines @@
         // AccessToken is actual token that authorizes and authenticates the requests.
         AccessToken string `json:"access_token"`
 
         // Expiry is the expiration time of the token or zero if it does not expire.
         Expiry time.Time `json:"expiry"`
 
         // TokenType is the type of token (e.g. "Bearer", which is default).
         TokenType string `json:"token_type,omitempty"`
 }
 
+// OAuth2Token returns the oauth2.Token containing the same data as tok.
+func (tok *Token) OAuth2Token() *oauth2.Token {
+        return &oauth2.Token{
+                AccessToken: tok.AccessToken,
+                Expiry:      tok.Expiry,
+                TokenType:   tok.TokenType,
+        }
+}
+
 // NewAuthenticator returns a new instance of Authenticator given its options.
 //
 // The authenticator is essentially a factory for http.RoundTripper that knows
 // how to use OAuth2 tokens. It is bound to the given context: uses its logger,
 // clock, transport and deadline.
 func NewAuthenticator(ctx context.Context, loginMode LoginMode, opts Options) *Authenticator {
         ctx = logging.SetField(ctx, "pkg", "auth")
 
         // Add default scope, sort scopes.
         if len(opts.Scopes) == 0 {
@@ skipping 232 matching lines @@
 type tokenSource struct {
         a *Authenticator
 }
 
 // Token is part of oauth2.TokenSource inteface.
 func (s tokenSource) Token() (*oauth2.Token, error) {
         tok, err := s.a.GetAccessToken(minAcceptedLifetime)
         if err != nil {
                 return nil, err
         }
-        return &oauth2.Token{
-                AccessToken: tok.AccessToken,
-                Expiry:      tok.Expiry,
-                TokenType:   tok.TokenType,
-        }, nil
+        return tok.OAuth2Token(), nil
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // Authenticator private methods.
 
 // ensureInitialized instantiates TokenProvider and reads token from cache.
 //
 // It is supposed to be called under the lock.
 func (a *Authenticator) ensureInitialized() error {
         if a.err != nil || a.provider != nil {
@@ skipping 420 matching lines @@
 
 // SecretsDir returns an absolute path to a directory (in $HOME) to keep secret
 // files in or an error if $HOME can't be determined.
 func SecretsDir() (string, error) {
         home, err := homedir.Dir()
         if err != nil {
                 return "", err
         }
         return filepath.Join(home, ".config", "chrome_infra", "auth"), nil
 }