|
| 1 | +package manager |
| 2 | + |
| 3 | +import ( |
| 4 | + "context" |
| 5 | + "crypto/tls" |
| 6 | + "net/http" |
| 7 | + "sync" |
| 8 | + "time" |
| 9 | + |
| 10 | + "golang.org/x/oauth2/clientcredentials" |
| 11 | + |
| 12 | + "github.com/plgd-dev/kit/log" |
| 13 | + "golang.org/x/oauth2" |
| 14 | +) |
| 15 | + |
| 16 | +// Manager holds certificates from filesystem watched for changes |
| 17 | +type Manager struct { |
| 18 | + mutex sync.Mutex |
| 19 | + config clientcredentials.Config |
| 20 | + requestTimeout time.Duration |
| 21 | + tickFrequency time.Duration |
| 22 | + startRefreshToken time.Time |
| 23 | + token *oauth2.Token |
| 24 | + httpClient *http.Client |
| 25 | + tokenErr error |
| 26 | + doneWg sync.WaitGroup |
| 27 | + done chan struct{} |
| 28 | +} |
| 29 | + |
| 30 | +// NewManagerFromConfiguration creates a new oauth manager which refreshing token. |
| 31 | +func NewManagerFromConfiguration(config Config, tlsCfg *tls.Config) (*Manager, error) { |
| 32 | + cfg := config.ToClientCrendtials() |
| 33 | + t := http.DefaultTransport.(*http.Transport).Clone() |
| 34 | + t.MaxIdleConns = 1 |
| 35 | + t.MaxConnsPerHost = 1 |
| 36 | + t.MaxIdleConnsPerHost = 1 |
| 37 | + t.IdleConnTimeout = time.Second * 30 |
| 38 | + t.TLSClientConfig = tlsCfg |
| 39 | + httpClient := &http.Client{ |
| 40 | + Transport: t, |
| 41 | + Timeout: config.RequestTimeout, |
| 42 | + } |
| 43 | + token, startRefreshToken, err := getToken(cfg, httpClient, config.RequestTimeout) |
| 44 | + if err != nil { |
| 45 | + return nil, err |
| 46 | + } |
| 47 | + |
| 48 | + mgr := &Manager{ |
| 49 | + config: cfg, |
| 50 | + token: token, |
| 51 | + startRefreshToken: startRefreshToken, |
| 52 | + requestTimeout: config.RequestTimeout, |
| 53 | + httpClient: httpClient, |
| 54 | + tickFrequency: config.TickFrequency, |
| 55 | + |
| 56 | + done: make(chan struct{}), |
| 57 | + } |
| 58 | + mgr.doneWg.Add(1) |
| 59 | + |
| 60 | + go mgr.watchToken() |
| 61 | + |
| 62 | + return mgr, nil |
| 63 | +} |
| 64 | + |
| 65 | +// GetToken returns token for clients |
| 66 | +func (a *Manager) GetToken(ctx context.Context) (*oauth2.Token, error) { |
| 67 | + a.mutex.Lock() |
| 68 | + defer a.mutex.Unlock() |
| 69 | + return a.token, a.tokenErr |
| 70 | +} |
| 71 | + |
| 72 | +// Close ends watching token |
| 73 | +func (a *Manager) Close() { |
| 74 | + if a.done != nil { |
| 75 | + close(a.done) |
| 76 | + a.doneWg.Wait() |
| 77 | + } |
| 78 | +} |
| 79 | + |
| 80 | +func (a *Manager) shouldRefresh() bool { |
| 81 | + return time.Now().After(a.startRefreshToken) |
| 82 | +} |
| 83 | + |
| 84 | +func getToken(cfg clientcredentials.Config, httpClient *http.Client, requestTimeout time.Duration) (*oauth2.Token, time.Time, error) { |
| 85 | + ctx, cancel := context.WithTimeout(context.Background(), requestTimeout) |
| 86 | + defer cancel() |
| 87 | + |
| 88 | + ctx = context.WithValue(ctx, oauth2.HTTPClient, httpClient) |
| 89 | + |
| 90 | + token, err := cfg.Token(ctx) |
| 91 | + var startRefreshToken time.Time |
| 92 | + if err == nil { |
| 93 | + now := time.Now() |
| 94 | + startRefreshToken = now.Add(token.Expiry.Sub(now) * 2 / 3) |
| 95 | + } |
| 96 | + return token, startRefreshToken, err |
| 97 | +} |
| 98 | + |
| 99 | +func (a *Manager) refreshToken() { |
| 100 | + token, startRefreshToken, err := getToken(a.config, a.httpClient, a.requestTimeout) |
| 101 | + if err != nil { |
| 102 | + log.Errorf("cannot refresh token: %v", err) |
| 103 | + } |
| 104 | + a.mutex.Lock() |
| 105 | + defer a.mutex.Unlock() |
| 106 | + a.token = token |
| 107 | + a.tokenErr = err |
| 108 | + a.startRefreshToken = startRefreshToken |
| 109 | +} |
| 110 | + |
| 111 | +func (a *Manager) watchToken() { |
| 112 | + defer a.doneWg.Done() |
| 113 | + t := time.NewTicker(a.tickFrequency) |
| 114 | + defer t.Stop() |
| 115 | + |
| 116 | + for { |
| 117 | + select { |
| 118 | + case <-a.done: |
| 119 | + return |
| 120 | + case <-t.C: |
| 121 | + if a.shouldRefresh() { |
| 122 | + a.refreshToken() |
| 123 | + } |
| 124 | + } |
| 125 | + } |
| 126 | +} |
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