summaryrefslogtreecommitdiffstats
path: root/golang/restapi/server.go
blob: 6fb4f3b9ac6be1b2f1b6dfc1bd5827118c295064 (plain)
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
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
// Code generated by go-swagger; DO NOT EDIT.

package restapi

import (
	"crypto/tls"
	"crypto/x509"
	"errors"
	"io/ioutil"
	"net"
	"net/http"
	"os"
	"strconv"
	"sync"
	"sync/atomic"
	"time"

	"github.com/go-openapi/runtime/flagext"
	"github.com/go-openapi/swag"
	flags "github.com/jessevdk/go-flags"
	graceful "github.com/tylerb/graceful"
    log "github.com/sirupsen/logrus" // manual hack for now (bnewbold)

	"git.archive.org/bnewbold/fatcat/golang/restapi/operations"
)

const (
	schemeHTTP  = "http"
	schemeHTTPS = "https"
	schemeUnix  = "unix"
)

var defaultSchemes []string

func init() {
	defaultSchemes = []string{
		schemeHTTP,
	}
}

// NewServer creates a new api fatcat server but does not configure it
func NewServer(api *operations.FatcatAPI) *Server {
	s := new(Server)

	s.shutdown = make(chan struct{})
	s.api = api
	return s
}

// ConfigureAPI configures the API and handlers.
func (s *Server) ConfigureAPI() {
	if s.api != nil {
		s.handler = configureAPI(s.api)
	}
}

// ConfigureFlags configures the additional flags defined by the handlers. Needs to be called before the parser.Parse
func (s *Server) ConfigureFlags() {
	if s.api != nil {
		configureFlags(s.api)
	}
}

// Server for the fatcat API
type Server struct {
	EnabledListeners []string         `long:"scheme" description:"the listeners to enable, this can be repeated and defaults to the schemes in the swagger spec"`
	CleanupTimeout   time.Duration    `long:"cleanup-timeout" description:"grace period for which to wait before shutting down the server" default:"10s"`
	MaxHeaderSize    flagext.ByteSize `long:"max-header-size" description:"controls the maximum number of bytes the server will read parsing the request header's keys and values, including the request line. It does not limit the size of the request body." default:"1MiB"`

	SocketPath    flags.Filename `long:"socket-path" description:"the unix socket to listen on" default:"/var/run/fatcat.sock"`
	domainSocketL net.Listener

	Host         string        `long:"host" description:"the IP to listen on" default:"localhost" env:"HOST"`
	Port         int           `long:"port" description:"the port to listen on for insecure connections, defaults to a random value" env:"PORT"`
	ListenLimit  int           `long:"listen-limit" description:"limit the number of outstanding requests"`
	KeepAlive    time.Duration `long:"keep-alive" description:"sets the TCP keep-alive timeouts on accepted connections. It prunes dead TCP connections ( e.g. closing laptop mid-download)" default:"3m"`
	ReadTimeout  time.Duration `long:"read-timeout" description:"maximum duration before timing out read of the request" default:"30s"`
	WriteTimeout time.Duration `long:"write-timeout" description:"maximum duration before timing out write of the response" default:"60s"`
	httpServerL  net.Listener

	TLSHost           string         `long:"tls-host" description:"the IP to listen on for tls, when not specified it's the same as --host" env:"TLS_HOST"`
	TLSPort           int            `long:"tls-port" description:"the port to listen on for secure connections, defaults to a random value" env:"TLS_PORT"`
	TLSCertificate    flags.Filename `long:"tls-certificate" description:"the certificate to use for secure connections" env:"TLS_CERTIFICATE"`
	TLSCertificateKey flags.Filename `long:"tls-key" description:"the private key to use for secure conections" env:"TLS_PRIVATE_KEY"`
	TLSCACertificate  flags.Filename `long:"tls-ca" description:"the certificate authority file to be used with mutual tls auth" env:"TLS_CA_CERTIFICATE"`
	TLSListenLimit    int            `long:"tls-listen-limit" description:"limit the number of outstanding requests"`
	TLSKeepAlive      time.Duration  `long:"tls-keep-alive" description:"sets the TCP keep-alive timeouts on accepted connections. It prunes dead TCP connections ( e.g. closing laptop mid-download)"`
	TLSReadTimeout    time.Duration  `long:"tls-read-timeout" description:"maximum duration before timing out read of the request"`
	TLSWriteTimeout   time.Duration  `long:"tls-write-timeout" description:"maximum duration before timing out write of the response"`
	httpsServerL      net.Listener

	api          *operations.FatcatAPI
	handler      http.Handler
	hasListeners bool
	shutdown     chan struct{}
	shuttingDown int32
}

// Logf logs message either via defined user logger or via system one if no user logger is defined.
func (s *Server) Logf(f string, args ...interface{}) {
	if s.api != nil && s.api.Logger != nil {
		s.api.Logger(f, args...)
	} else {
		log.Printf(f, args...)
	}
}

// Fatalf logs message either via defined user logger or via system one if no user logger is defined.
// Exits with non-zero status after printing
func (s *Server) Fatalf(f string, args ...interface{}) {
	if s.api != nil && s.api.Logger != nil {
		s.api.Logger(f, args...)
		os.Exit(1)
	} else {
		log.Fatalf(f, args...)
	}
}

// SetAPI configures the server with the specified API. Needs to be called before Serve
func (s *Server) SetAPI(api *operations.FatcatAPI) {
	if api == nil {
		s.api = nil
		s.handler = nil
		return
	}

	s.api = api
	s.api.Logger = log.Printf
	s.handler = configureAPI(api)
}

func (s *Server) hasScheme(scheme string) bool {
	schemes := s.EnabledListeners
	if len(schemes) == 0 {
		schemes = defaultSchemes
	}

	for _, v := range schemes {
		if v == scheme {
			return true
		}
	}
	return false
}

// Serve the api
func (s *Server) Serve() (err error) {
	if !s.hasListeners {
		if err = s.Listen(); err != nil {
			return err
		}
	}

	// set default handler, if none is set
	if s.handler == nil {
		if s.api == nil {
			return errors.New("can't create the default handler, as no api is set")
		}

		s.SetHandler(s.api.Serve(nil))
	}

	var wg sync.WaitGroup

	if s.hasScheme(schemeUnix) {
		domainSocket := &graceful.Server{Server: new(http.Server)}
		domainSocket.MaxHeaderBytes = int(s.MaxHeaderSize)
		domainSocket.Handler = s.handler
		domainSocket.LogFunc = s.Logf
		if int64(s.CleanupTimeout) > 0 {
			domainSocket.Timeout = s.CleanupTimeout
		}

		configureServer(domainSocket, "unix", string(s.SocketPath))

		wg.Add(2)
		s.Logf("Serving fatcat at unix://%s", s.SocketPath)
		go func(l net.Listener) {
			defer wg.Done()
			if err := domainSocket.Serve(l); err != nil {
				s.Fatalf("%v", err)
			}
			s.Logf("Stopped serving fatcat at unix://%s", s.SocketPath)
		}(s.domainSocketL)
		go s.handleShutdown(&wg, domainSocket)
	}

	if s.hasScheme(schemeHTTP) {
		httpServer := &graceful.Server{Server: new(http.Server)}
		httpServer.MaxHeaderBytes = int(s.MaxHeaderSize)
		httpServer.ReadTimeout = s.ReadTimeout
		httpServer.WriteTimeout = s.WriteTimeout
		httpServer.SetKeepAlivesEnabled(int64(s.KeepAlive) > 0)
		httpServer.TCPKeepAlive = s.KeepAlive
		if s.ListenLimit > 0 {
			httpServer.ListenLimit = s.ListenLimit
		}

		if int64(s.CleanupTimeout) > 0 {
			httpServer.Timeout = s.CleanupTimeout
		}

		httpServer.Handler = s.handler
		httpServer.LogFunc = s.Logf

		configureServer(httpServer, "http", s.httpServerL.Addr().String())

		wg.Add(2)
		s.Logf("Serving fatcat at http://%s", s.httpServerL.Addr())
		go func(l net.Listener) {
			defer wg.Done()
			if err := httpServer.Serve(l); err != nil {
				s.Fatalf("%v", err)
			}
			s.Logf("Stopped serving fatcat at http://%s", l.Addr())
		}(s.httpServerL)
		go s.handleShutdown(&wg, httpServer)
	}

	if s.hasScheme(schemeHTTPS) {
		httpsServer := &graceful.Server{Server: new(http.Server)}
		httpsServer.MaxHeaderBytes = int(s.MaxHeaderSize)
		httpsServer.ReadTimeout = s.TLSReadTimeout
		httpsServer.WriteTimeout = s.TLSWriteTimeout
		httpsServer.SetKeepAlivesEnabled(int64(s.TLSKeepAlive) > 0)
		httpsServer.TCPKeepAlive = s.TLSKeepAlive
		if s.TLSListenLimit > 0 {
			httpsServer.ListenLimit = s.TLSListenLimit
		}
		if int64(s.CleanupTimeout) > 0 {
			httpsServer.Timeout = s.CleanupTimeout
		}
		httpsServer.Handler = s.handler
		httpsServer.LogFunc = s.Logf

		// Inspired by https://blog.bracebin.com/achieving-perfect-ssl-labs-score-with-go
		httpsServer.TLSConfig = &tls.Config{
			// Causes servers to use Go's default ciphersuite preferences,
			// which are tuned to avoid attacks. Does nothing on clients.
			PreferServerCipherSuites: true,
			// Only use curves which have assembly implementations
			// https://github.com/golang/go/tree/master/src/crypto/elliptic
			CurvePreferences: []tls.CurveID{tls.CurveP256},
			// Use modern tls mode https://wiki.mozilla.org/Security/Server_Side_TLS#Modern_compatibility
			NextProtos: []string{"http/1.1", "h2"},
			// https://www.owasp.org/index.php/Transport_Layer_Protection_Cheat_Sheet#Rule_-_Only_Support_Strong_Protocols
			MinVersion: tls.VersionTLS12,
			// These ciphersuites support Forward Secrecy: https://en.wikipedia.org/wiki/Forward_secrecy
			CipherSuites: []uint16{
				tls.TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
				tls.TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
				tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
				tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
			},
		}

		if s.TLSCertificate != "" && s.TLSCertificateKey != "" {
			httpsServer.TLSConfig.Certificates = make([]tls.Certificate, 1)
			httpsServer.TLSConfig.Certificates[0], err = tls.LoadX509KeyPair(string(s.TLSCertificate), string(s.TLSCertificateKey))
		}

		if s.TLSCACertificate != "" {
			caCert, caCertErr := ioutil.ReadFile(string(s.TLSCACertificate))
			if caCertErr != nil {
				log.Fatal(caCertErr)
			}
			caCertPool := x509.NewCertPool()
			caCertPool.AppendCertsFromPEM(caCert)
			httpsServer.TLSConfig.ClientCAs = caCertPool
			httpsServer.TLSConfig.ClientAuth = tls.RequireAndVerifyClientCert
		}

		configureTLS(httpsServer.TLSConfig)
		httpsServer.TLSConfig.BuildNameToCertificate()

		if err != nil {
			return err
		}

		if len(httpsServer.TLSConfig.Certificates) == 0 {
			if s.TLSCertificate == "" {
				if s.TLSCertificateKey == "" {
					s.Fatalf("the required flags `--tls-certificate` and `--tls-key` were not specified")
				}
				s.Fatalf("the required flag `--tls-certificate` was not specified")
			}
			if s.TLSCertificateKey == "" {
				s.Fatalf("the required flag `--tls-key` was not specified")
			}
		}

		configureServer(httpsServer, "https", s.httpsServerL.Addr().String())

		wg.Add(2)
		s.Logf("Serving fatcat at https://%s", s.httpsServerL.Addr())
		go func(l net.Listener) {
			defer wg.Done()
			if err := httpsServer.Serve(l); err != nil {
				s.Fatalf("%v", err)
			}
			s.Logf("Stopped serving fatcat at https://%s", l.Addr())
		}(tls.NewListener(s.httpsServerL, httpsServer.TLSConfig))
		go s.handleShutdown(&wg, httpsServer)
	}

	wg.Wait()
	return nil
}

// Listen creates the listeners for the server
func (s *Server) Listen() error {
	if s.hasListeners { // already done this
		return nil
	}

	if s.hasScheme(schemeHTTPS) {
		// Use http host if https host wasn't defined
		if s.TLSHost == "" {
			s.TLSHost = s.Host
		}
		// Use http listen limit if https listen limit wasn't defined
		if s.TLSListenLimit == 0 {
			s.TLSListenLimit = s.ListenLimit
		}
		// Use http tcp keep alive if https tcp keep alive wasn't defined
		if int64(s.TLSKeepAlive) == 0 {
			s.TLSKeepAlive = s.KeepAlive
		}
		// Use http read timeout if https read timeout wasn't defined
		if int64(s.TLSReadTimeout) == 0 {
			s.TLSReadTimeout = s.ReadTimeout
		}
		// Use http write timeout if https write timeout wasn't defined
		if int64(s.TLSWriteTimeout) == 0 {
			s.TLSWriteTimeout = s.WriteTimeout
		}
	}

	if s.hasScheme(schemeUnix) {
		domSockListener, err := net.Listen("unix", string(s.SocketPath))
		if err != nil {
			return err
		}
		s.domainSocketL = domSockListener
	}

	if s.hasScheme(schemeHTTP) {
		listener, err := net.Listen("tcp", net.JoinHostPort(s.Host, strconv.Itoa(s.Port)))
		if err != nil {
			return err
		}

		h, p, err := swag.SplitHostPort(listener.Addr().String())
		if err != nil {
			return err
		}
		s.Host = h
		s.Port = p
		s.httpServerL = listener
	}

	if s.hasScheme(schemeHTTPS) {
		tlsListener, err := net.Listen("tcp", net.JoinHostPort(s.TLSHost, strconv.Itoa(s.TLSPort)))
		if err != nil {
			return err
		}

		sh, sp, err := swag.SplitHostPort(tlsListener.Addr().String())
		if err != nil {
			return err
		}
		s.TLSHost = sh
		s.TLSPort = sp
		s.httpsServerL = tlsListener
	}

	s.hasListeners = true
	return nil
}

// Shutdown server and clean up resources
func (s *Server) Shutdown() error {
	if atomic.LoadInt32(&s.shuttingDown) != 0 {
		s.Logf("already shutting down")
		return nil
	}
	s.shutdown <- struct{}{}
	return nil
}

func (s *Server) handleShutdown(wg *sync.WaitGroup, server *graceful.Server) {
	defer wg.Done()
	for {
		select {
		case <-s.shutdown:
			atomic.AddInt32(&s.shuttingDown, 1)
			server.Stop(s.CleanupTimeout)
			<-server.StopChan()
			s.api.ServerShutdown()
			return
		case <-server.StopChan():
			atomic.AddInt32(&s.shuttingDown, 1)
			s.api.ServerShutdown()
			return
		}
	}
}

// GetHandler returns a handler useful for testing
func (s *Server) GetHandler() http.Handler {
	return s.handler
}

// SetHandler allows for setting a http handler on this server
func (s *Server) SetHandler(handler http.Handler) {
	s.handler = handler
}

// UnixListener returns the domain socket listener
func (s *Server) UnixListener() (net.Listener, error) {
	if !s.hasListeners {
		if err := s.Listen(); err != nil {
			return nil, err
		}
	}
	return s.domainSocketL, nil
}

// HTTPListener returns the http listener
func (s *Server) HTTPListener() (net.Listener, error) {
	if !s.hasListeners {
		if err := s.Listen(); err != nil {
			return nil, err
		}
	}
	return s.httpServerL, nil
}

// TLSListener returns the https listener
func (s *Server) TLSListener() (net.Listener, error) {
	if !s.hasListeners {
		if err := s.Listen(); err != nil {
			return nil, err
		}
	}
	return s.httpsServerL, nil
}