/
gke.go
82 lines (75 loc) · 2.64 KB
/
gke.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
/*
Copyright 2021 The Crossplane 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 gke contains utilities for authenticating to GKE clusters.
package gke
import (
"context"
"encoding/json"
"net/http"
"github.com/pkg/errors"
"golang.org/x/oauth2"
"golang.org/x/oauth2/google"
"k8s.io/client-go/rest"
)
// DefaultScopes for GKE authentication.
var DefaultScopes []string = []string{
"https://www.googleapis.com/auth/cloud-platform",
"https://www.googleapis.com/auth/userinfo.email",
}
// WrapRESTConfig configures the supplied REST config to use OAuth2 bearer
// tokens fetched using the supplied Google Application Credentials.
func WrapRESTConfig(ctx context.Context, rc *rest.Config, credentials []byte, scopes ...string) error {
var ts oauth2.TokenSource
if credentials != nil {
if isJSON(credentials) {
// If credentials are in a JSON format, extract the credential from the JSON
// CredentialsFromJSON creates a TokenSource that handles token caching.
creds, err := google.CredentialsFromJSON(ctx, credentials, scopes...)
if err != nil {
return errors.Wrap(err, "cannot load Google Application Credentials from JSON")
}
ts = creds.TokenSource
rc.Wrap(func(rt http.RoundTripper) http.RoundTripper {
return &oauth2.Transport{Source: ts, Base: rt}
})
return nil
}
// if the credential not in a JSON format, treat the credential as an access token
t := oauth2.Token{
AccessToken: string(credentials),
}
if ok := t.Valid(); !ok {
return errors.New("Access token invalid")
}
ts = oauth2.StaticTokenSource(&t)
rc.Wrap(func(rt http.RoundTripper) http.RoundTripper {
return &oauth2.Transport{Source: ts, Base: rt}
})
return nil
}
var t *oauth2.Token
// DefaultTokenSource retrieves a token source from an injected identity.
gsrc, err := google.DefaultTokenSource(ctx, scopes...)
if err != nil {
return errors.Wrap(err, "failed to extract default credentials source")
}
ts = oauth2.ReuseTokenSource(t, gsrc)
rc.Wrap(func(rt http.RoundTripper) http.RoundTripper {
return &oauth2.Transport{Source: ts, Base: rt}
})
return nil
}
func isJSON(b []byte) bool {
var js json.RawMessage
return json.Unmarshal(b, &js) == nil
}