vendor/google.golang.org/api/internal/creds.go

   1 // Copyright 2017 Google LLC
   2 //
   3 // Licensed under the Apache License, Version 2.0 (the "License");
   4 // you may not use this file except in compliance with the License.
   5 // You may obtain a copy of the License at
   6 //
   7 //      http://www.apache.org/licenses/LICENSE-2.0
   8 //
   9 // Unless required by applicable law or agreed to in writing, software
  10 // distributed under the License is distributed on an "AS IS" BASIS,
  11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 // See the License for the specific language governing permissions and
  13 // limitations under the License.
  14
  15 package internal
  16
  17 import (
  18         "context"
  19         "fmt"
  20         "io/ioutil"
  21
  22         "golang.org/x/oauth2/google"
  23 )
  24
  25 // Creds returns credential information obtained from DialSettings, or if none, then
  26 // it returns default credential information.
  27 func Creds(ctx context.Context, ds *DialSettings) (*google.DefaultCredentials, error) {
  28         if ds.Credentials != nil {
  29                 return ds.Credentials, nil
  30         }
  31         if ds.CredentialsJSON != nil {
  32                 return google.CredentialsFromJSON(ctx, ds.CredentialsJSON, ds.Scopes...)
  33         }
  34         if ds.CredentialsFile != "" {
  35                 data, err := ioutil.ReadFile(ds.CredentialsFile)
  36                 if err != nil {
  37                         return nil, fmt.Errorf("cannot read credentials file: %v", err)
  38                 }
  39                 return google.CredentialsFromJSON(ctx, data, ds.Scopes...)
  40         }
  41         if ds.TokenSource != nil {
  42                 return &google.DefaultCredentials{TokenSource: ds.TokenSource}, nil
  43         }
  44         return google.FindDefaultCredentials(ctx, ds.Scopes...)
  45 }