Add unique request id

NOTICES.txt

@@ -146,3 +146,9 @@ golang.org/go
 https://github.com/golang/go
 License: BSD 3-clause (https://github.com/golang/go/LICENSE)
 Copyright (c) 2009 The Go Authors. All rights reserved.
+
+
+github.com/rogpeppe/fastuuid
+https://github.com/rogpeppe/fastuuid.git
+License: BSD 3-clause (https://github.com/google/uuid/LICENSE)
+Copyright © 2014, Roger Peppe All rights reserved.

config/config.go

@@ -57,6 +57,7 @@ type Proxy struct {
 	TLSHeader             string
 	TLSHeaderValue        string
 	GZIPContentTypes      *regexp.Regexp
+	RequestID             string
 }
 
 type Runtime struct {

config/load.go

@@ -126,6 +126,7 @@ func load(cmdline, environ, envprefix []string, props *properties.Properties) (c
 	f.StringVar(&cfg.Proxy.ClientIPHeader, "proxy.header.clientip", defaultConfig.Proxy.ClientIPHeader, "header for the request ip")
 	f.StringVar(&cfg.Proxy.TLSHeader, "proxy.header.tls", defaultConfig.Proxy.TLSHeader, "header for TLS connections")
 	f.StringVar(&cfg.Proxy.TLSHeaderValue, "proxy.header.tls.value", defaultConfig.Proxy.TLSHeaderValue, "value for TLS connection header")
+	f.StringVar(&cfg.Proxy.RequestID, "proxy.header.requestid", defaultConfig.Proxy.RequestID, "header for reqest id")
 	f.StringVar(&gzipContentTypesValue, "proxy.gzip.contenttype", defaultValues.GZIPContentTypesValue, "regexp of content types to compress")
 	f.StringSliceVar(&listenerValue, "proxy.addr", defaultValues.ListenerValue, "listener config")
 	f.KVSliceVar(&certSourcesValue, "proxy.cs", defaultValues.CertSourcesValue, "certificate sources")

config/load_test.go

@@ -302,6 +302,13 @@ func TestLoad(t *testing.T) {
 				return cfg
 			},
 		},
+		{
+			args: []string{"-proxy.header.requestid", "value"},
+			cfg: func(cfg *Config) *Config {
+				cfg.Proxy.RequestID = "value"
+				return cfg
+			},
+		},
 		{
 			args: []string{"-proxy.gzip.contenttype", `^text/.*$`},
 			cfg: func(cfg *Config) *Config {

fabio.properties

@@ -353,6 +353,15 @@
 # proxy.header.tls.value =
 
 
+# proxy.header.requestid configures the header for the adding a unique request id.
+# When set non-empty value the proxy will set this header on every request to the
+# unique UUID value.
+#
+# The default is
+#
+# proxy.header.requestid =
+
+
 # proxy.gzip.contenttype configures which responses should be compressed.
 #
 # By default, responses sent to the client are not compressed even if the

proxy/http_integration_test.go

@@ -50,6 +50,31 @@ func TestProxyProducesCorrectXffHeader(t *testing.T) {
 	}
 }
 
+func TestProxyRequestIDHeader(t *testing.T) {
+	got := "not called"
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		got = r.Header.Get("X-Request-ID")
+	}))
+	defer server.Close()
+
+	proxy := httptest.NewServer(&HTTPProxy{
+		Config:    config.Proxy{RequestID: "X-Request-Id"},
+		Transport: http.DefaultTransport,
+		UUID:      func() string { return "f47ac10b-58cc-0372-8567-0e02b2c3d479" },
+		Lookup: func(r *http.Request) *route.Target {
+			return &route.Target{URL: mustParse(server.URL)}
+		},
+	})
+	defer proxy.Close()
+
+	req, _ := http.NewRequest("GET", proxy.URL, nil)
+	mustDo(req)
+
+	if want := "f47ac10b-58cc-0372-8567-0e02b2c3d479"; got != want {
+		t.Errorf("got %v, but want %v", got, want)
+	}
+}
+
 func TestProxyNoRouteStaus(t *testing.T) {
 	proxy := httptest.NewServer(&HTTPProxy{
 		Config:    config.Proxy{NoRouteStatus: 999},

proxy/http_proxy.go

@@ -15,6 +15,7 @@ import (
 	"github.com/fabiolb/fabio/metrics"
 	"github.com/fabiolb/fabio/proxy/gzip"
 	"github.com/fabiolb/fabio/route"
+	"github.com/fabiolb/fabio/uuid"
 )
 
 // HTTPProxy is a dynamic reverse proxy for HTTP and HTTPS protocols.
@@ -48,6 +49,10 @@ type HTTPProxy struct {
 
 	// Logger is the access logger for the requests.
 	Logger logger.Logger
+
+	// UUID returns a unique id in uuid format.
+	// If UUID is nil, uuid.NewUUID() is used.
+	UUID func() string
 }
 
 func (p *HTTPProxy) ServeHTTP(w http.ResponseWriter, r *http.Request) {
@@ -66,6 +71,16 @@ func (p *HTTPProxy) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	if p.Config.RequestID != "" {
+		var id string
+		if p.UUID == nil {
+			id = uuid.NewUUID()
+		} else {
+			id = p.UUID()
+		}
+		r.Header.Set(p.Config.RequestID, id)
+	}
+
 	// build the request url since r.URL will get modified
 	// by the reverse proxy and contains only the RequestURI anyway
 	requestURL := &url.URL{

uuid/format.go

@@ -0,0 +1,62 @@
+package uuid
+
+// Fast UUID formatting adapted from
+// https://github.com/m4rw3r/uuid/blob/master/uuid.go
+
+// hexchar2byte contains the integer byte-value represented by a hexadecimal character,
+// 255 if it is an invalid character.
+var hexchar2byte = []byte{
+	255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+	255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+	255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 255, 255, 255, 255, 255, 255,
+	255, 10, 11, 12, 13, 14, 15, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+	255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+	255, 10, 11, 12, 13, 14, 15, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+	255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+	255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+	255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+	255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+	255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+	255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+	255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+	255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+	255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+}
+
+// halfbyte2hexchar contains an array of character values corresponding to
+// hexadecimal values for the position in the array, 0 to 15 (0x0-0xf, half-byte).
+var halfbyte2hexchar = []byte{
+	48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 97, 98, 99, 100, 101, 102,
+}
+
+// ToString formats raw UUID bytes as a standard UUID string
+func ToString(u [24]byte) string {
+	/* It is a lot (~10x) faster to allocate a byte slice of specific size and
+	   then use a lookup table to write the characters to the byte-array and
+	   finally cast to string instead of using fmt.Sprintf() */
+	/* Slightly faster to not use make([]byte, 36), guessing either call
+	   overhead or slice-header overhead is the cause */
+	b := [36]byte{}
+
+	for i, n := range []int{
+		0, 2, 4, 6,
+		9, 11,
+		14, 16,
+		19, 21,
+		24, 26, 28, 30, 32, 34,
+	} {
+		b[n] = halfbyte2hexchar[(u[i]>>4)&0x0f]
+		b[n+1] = halfbyte2hexchar[u[i]&0x0f]
+	}
+
+	b[8] = '-'
+	b[13] = '-'
+	b[18] = '-'
+	b[23] = '-'
+
+	/* Oddly does not seem to cause a memory allocation,
+	   internal data-array is most likely just moved over
+	   to the string-header: */
+	return string(b[:])
+}

uuid/uuid.go

@@ -0,0 +1,12 @@
+package uuid
+
+import (
+	"github.com/rogpeppe/fastuuid"
+)
+
+var generator = fastuuid.MustNewGenerator()
+
+// NewUUID return UUID in string fromat
+func NewUUID() string {
+	return ToString(generator.Next())
+}

vendor/vendor.json

@@ -188,6 +188,12 @@
 			"revision": "3e5e593311103d49927c8d2b0fd93ccdfe4a525c",
 			"revisionTime": "2015-07-19T09:56:14-07:00"
 		},
+		{
+			"checksumSHA1": "ehRkDJisGCCSYdNgyvs1gSywSPE=",
+			"path": "github.com/rogpeppe/fastuuid",
+			"revision": "6724a57986aff9bff1a1770e9347036def7c89f6",
+			"revisionTime": "2015-01-06T09:31:45Z"
+		},
 		{
 			"checksumSHA1": "EYkx4sXDLSEd1xUtGoXRsfd5cpw=",
 			"path": "github.com/ryanuber/go-glob",