Issue #278: Add service name field to access log

This patch adds a $upstream_service field to the
available access log fields.

Fixes #278

fabio.properties

@@ -415,6 +415,7 @@
 #   $upstream_request_scheme - upstream request scheme
 #   $upstream_request_uri    - upstream request URI
 #   $upstream_request_url    - upstream request URL
+#   $upstream_service        - name of the upstream service
 #
 # The default is
 #

logger/logger.go

@@ -79,6 +79,10 @@ type Event struct {
 	// upstream server which handled the proxied request.
 	UpstreamAddr string
 
+	// UpstreamService is the name of the upstream service as
+	// defined in the route.
+	UpstreamService string
+
 	// UpstreamURL is the URL which was sent to the upstream server.
 	// It should only be set for HTTP log events.
 	UpstreamURL *url.URL

logger/logger_test.go

@@ -79,9 +79,10 @@ func TestLog(t *testing.T) {
 				RemoteAddr: "5.6.7.8:1234",
 			},
 		},
-		RequestURL:   rurl,
-		UpstreamAddr: uurl.Host,
-		UpstreamURL:  uurl,
+		RequestURL:      rurl,
+		UpstreamAddr:    uurl.Host,
+		UpstreamService: "svc-a",
+		UpstreamURL:     uurl,
 	}
 
 	tests := []struct {
@@ -121,6 +122,7 @@ func TestLog(t *testing.T) {
 		{"$upstream_request_scheme", "http\n"},
 		{"$upstream_request_uri", "/foo?q=x\n"},
 		{"$upstream_request_url", "http://7.8.9.0:5678/foo?q=x\n"},
+		{"$upstream_service", "svc-a\n"},
 	}
 
 	for _, tt := range tests {

logger/pattern.go

@@ -256,6 +256,9 @@ var fields = map[string]field{
 		}
 		b.WriteString(e.UpstreamURL.String())
 	},
+	"$upstream_service": func(b *bytes.Buffer, e *Event) {
+		b.WriteString(e.UpstreamService)
+	},
 }
 
 var shortMonthNames = []string{

proxy/http_integration_test.go

@@ -122,7 +122,10 @@ func TestProxyLogOutput(t *testing.T) {
 		},
 		Transport: http.DefaultTransport,
 		Lookup: func(r *http.Request) *route.Target {
-			return &route.Target{URL: mustParse(server.URL)}
+			return &route.Target{
+				Service: "svc-a",
+				URL:     mustParse(server.URL),
+			}
 		},
 		Logger: l,
 	}
@@ -182,6 +185,7 @@ func TestProxyLogOutput(t *testing.T) {
 		"upstream_request_scheme:" + upstreamURL.Scheme,
 		"upstream_request_uri:/foo?x=y",
 		"upstream_request_url:" + upstreamURL.String() + "/foo?x=y",
+		"upstream_service:svc-a",
 	}
 
 	data := string(b.Bytes())

proxy/http_proxy.go

@@ -148,13 +148,14 @@ func (p *HTTPProxy) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	// write access log
 	if p.Logger != nil {
 		p.Logger.Log(&logger.Event{
-			Start:        start,
-			End:          end,
-			Request:      r,
-			Response:     resp,
-			RequestURL:   requestURL,
-			UpstreamAddr: targetURL.Host,
-			UpstreamURL:  targetURL,
+			Start:           start,
+			End:             end,
+			Request:         r,
+			Response:        resp,
+			RequestURL:      requestURL,
+			UpstreamAddr:    targetURL.Host,
+			UpstreamService: t.Service,
+			UpstreamURL:     targetURL,
 		})
 	}
 }