ceph-csi/vendor/google.golang.org/grpc/credentials/google/google.go
2018-11-26 13:23:56 -05:00

102 lines
3.2 KiB
Go

/*
*
* Copyright 2018 gRPC authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
// Package google defines credentials for google cloud services.
package google
import (
"fmt"
"time"
"golang.org/x/net/context"
"google.golang.org/grpc/credentials"
"google.golang.org/grpc/credentials/alts"
"google.golang.org/grpc/credentials/oauth"
"google.golang.org/grpc/grpclog"
"google.golang.org/grpc/internal"
)
const tokenRequestTimeout = 30 * time.Second
// NewDefaultCredentials returns a credentials bundle that is configured to work
// with google services.
//
// This API is experimental.
func NewDefaultCredentials() credentials.Bundle {
c := &creds{}
bundle, err := c.NewWithMode(internal.CredsBundleModeFallback)
if err != nil {
grpclog.Warningf("google default creds: failed to create new creds: %v", err)
}
return bundle
}
// creds implements credentials.Bundle.
type creds struct {
// Supported modes are defined in internal/internal.go.
mode string
// The transport credentials associated with this bundle.
transportCreds credentials.TransportCredentials
// The per RPC credentials associated with this bundle.
perRPCCreds credentials.PerRPCCredentials
}
func (c *creds) TransportCredentials() credentials.TransportCredentials {
return c.transportCreds
}
func (c *creds) PerRPCCredentials() credentials.PerRPCCredentials {
if c == nil {
return nil
}
return c.perRPCCreds
}
// NewWithMode should make a copy of Bundle, and switch mode. Modifying the
// existing Bundle may cause races.
func (c *creds) NewWithMode(mode string) (credentials.Bundle, error) {
newCreds := &creds{mode: mode}
// Create transport credentials.
switch mode {
case internal.CredsBundleModeFallback:
newCreds.transportCreds = credentials.NewTLS(nil)
case internal.CredsBundleModeBackendFromBalancer, internal.CredsBundleModeBalancer:
// Only the clients can use google default credentials, so we only need
// to create new ALTS client creds here.
newCreds.transportCreds = alts.NewClientCreds(alts.DefaultClientOptions())
default:
return nil, fmt.Errorf("google default creds: unsupported mode: %v", mode)
}
if mode == internal.CredsBundleModeFallback || mode == internal.CredsBundleModeBackendFromBalancer {
// Create per RPC credentials.
// For the time being, we required per RPC credentials for both TLS and
// ALTS. In the future, this will only be required for TLS.
ctx, cancel := context.WithTimeout(context.Background(), tokenRequestTimeout)
defer cancel()
var err error
newCreds.perRPCCreds, err = oauth.NewApplicationDefault(ctx)
if err != nil {
grpclog.Warningf("google default creds: failed to create application oauth: %v", err)
}
}
return newCreds, nil
}