Add rewrites annotation

examples/rewrites/README.md

@@ -0,0 +1,41 @@
+# Rewrites Support
+
+To load balance an application that requires rewrites with NGINX Ingress controllers, you need to add the **nginx.org/rewrites** annotation to your Ingress resource definition. The annotation specifies which services need rewrites. The annotation syntax is as follows:
+```
+nginx.org/rewrites: "serviceName=service1 rewrite=/rewrite1/[;serviceName=service2 rewrite=/rewrite2/;...]"
+```
+
+In the following example we load balance two applications, which require rewrites:
+```yaml
+apiVersion: extensions/v1beta1
+kind: Ingress
+metadata:
+  name: cafe-ingress
+  annotations:
+    nginx.org/rewrites: "serviceName=tea-svc rewrite=/;serviceName=coffee-svc rewrite=/beans/"
+spec:
+  rules:
+  - host: cafe.example.com
+    http:
+      paths:
+      - path: /tea/
+        backend:
+          serviceName: tea-svc
+          servicePort: 80
+      - path: /coffee/
+        backend:
+          serviceName: coffee-svc
+          servicePort: 80
+```
+
+Requests to the tea service are rewritten as follows:
+
+* /tea -> gets redirected to /tea/ first
+* /tea/ -> /
+* /tea/abc -> /abc
+
+Requests to the coffee service are rewritten as follows:
+
+* /coffee -> gets redirected to /coffee/ first
+* /coffee/ -> /beans/
+* /coffee/abc -> /beans/abc

nginx-controller/nginx/configurator.go

@@ -80,6 +80,7 @@ func (cnf *Configurator) generateNginxCfg(ingEx *IngressEx, pems map[string]stri
 	upstreams := make(map[string]Upstream)
 
 	wsServices := getWebsocketServices(ingEx)
+	rewrites := getRewrites(ingEx)
 	sslServices := getSSLServices(ingEx)
 
 	if ingEx.Ingress.Spec.Backend != nil {
@@ -120,7 +121,7 @@ func (cnf *Configurator) generateNginxCfg(ingEx *IngressEx, pems map[string]stri
 				upstreams[upsName] = upstream
 			}
 
-			loc := createLocation(pathOrDefault(path.Path), upstreams[upsName], &ingCfg, wsServices[path.Backend.ServiceName], sslServices[path.Backend.ServiceName])
+			loc := createLocation(pathOrDefault(path.Path), upstreams[upsName], &ingCfg, wsServices[path.Backend.ServiceName], rewrites[path.Backend.ServiceName], sslServices[path.Backend.ServiceName])
 			locations = append(locations, loc)
 
 			if loc.Path == "/" {
@@ -130,7 +131,7 @@ func (cnf *Configurator) generateNginxCfg(ingEx *IngressEx, pems map[string]stri
 
 		if rootLocation == false && ingEx.Ingress.Spec.Backend != nil {
 			upsName := getNameForUpstream(ingEx.Ingress, emptyHost, ingEx.Ingress.Spec.Backend.ServiceName)
-			loc := createLocation(pathOrDefault("/"), upstreams[upsName], &ingCfg, wsServices[ingEx.Ingress.Spec.Backend.ServiceName], sslServices[ingEx.Ingress.Spec.Backend.ServiceName])
+			loc := createLocation(pathOrDefault("/"), upstreams[upsName], &ingCfg, wsServices[ingEx.Ingress.Spec.Backend.ServiceName], rewrites[ingEx.Ingress.Spec.Backend.ServiceName], sslServices[ingEx.Ingress.Spec.Backend.ServiceName])
 			locations = append(locations, loc)
 		}
 
@@ -151,7 +152,7 @@ func (cnf *Configurator) generateNginxCfg(ingEx *IngressEx, pems map[string]stri
 
 		upsName := getNameForUpstream(ingEx.Ingress, emptyHost, ingEx.Ingress.Spec.Backend.ServiceName)
 
-		loc := createLocation(pathOrDefault("/"), upstreams[upsName], &ingCfg, wsServices[ingEx.Ingress.Spec.Backend.ServiceName], sslServices[ingEx.Ingress.Spec.Backend.ServiceName])
+		loc := createLocation(pathOrDefault("/"), upstreams[upsName], &ingCfg, wsServices[ingEx.Ingress.Spec.Backend.ServiceName], rewrites[ingEx.Ingress.Spec.Backend.ServiceName], sslServices[ingEx.Ingress.Spec.Backend.ServiceName])
 		locations = append(locations, loc)
 
 		server.Locations = locations
@@ -188,6 +189,42 @@ func getWebsocketServices(ingEx *IngressEx) map[string]bool {
 	return wsServices
 }
 
+func getRewrites(ingEx *IngressEx) map[string]string {
+	rewrites := make(map[string]string)
+
+	if services, exists := ingEx.Ingress.Annotations["nginx.org/rewrites"]; exists {
+		for _, svc := range strings.Split(services, ";") {
+			if serviceName, rewrite, err := parseRewrites(svc); err != nil {
+				glog.Errorf("In %v nginx.org/rewrites contains invalid declaration: %v, ignoring", ingEx.Ingress.Name, err)
+			} else {
+				rewrites[serviceName] = rewrite
+			}
+		}
+	}
+
+	return rewrites
+}
+
+func parseRewrites(service string) (serviceName string, rewrite string, err error) {
+	parts := strings.SplitN(service, " ", 2)
+
+	if len(parts) != 2 {
+		return "", "", fmt.Errorf("Invalid rewrite format: %s\n", service)
+	}
+
+	svcNameParts := strings.Split(parts[0], "=")
+	if len(svcNameParts) != 2 {
+		return "", "", fmt.Errorf("Invalid rewrite format: %s\n", svcNameParts)
+	}
+
+	rwPathParts := strings.Split(parts[1], "=")
+	if len(rwPathParts) != 2 {
+		return "", "", fmt.Errorf("Invalid rewrite format: %s\n", rwPathParts)
+	}
+
+	return svcNameParts[1], rwPathParts[1], nil
+}
+
 func getSSLServices(ingEx *IngressEx) map[string]bool {
 	sslServices := make(map[string]bool)
 
@@ -200,14 +237,15 @@ func getSSLServices(ingEx *IngressEx) map[string]bool {
 	return sslServices
 }
 
-func createLocation(path string, upstream Upstream, cfg *Config, websocket bool, ssl bool) Location {
+func createLocation(path string, upstream Upstream, cfg *Config, websocket bool, rewrite string, ssl bool) Location {
 	loc := Location{
 		Path:                path,
 		Upstream:            upstream,
 		ProxyConnectTimeout: cfg.ProxyConnectTimeout,
 		ProxyReadTimeout:    cfg.ProxyReadTimeout,
 		ClientMaxBodySize:   cfg.ClientMaxBodySize,
 		Websocket:           websocket,
+		Rewrite:             rewrite,
 		SSL:                 ssl,
 	}
 

nginx-controller/nginx/configurator_test.go

@@ -18,3 +18,25 @@ func TestPathOrDefaultReturnActual(t *testing.T) {
 		t.Errorf("pathOrDefault(%q) should return %q", path, path)
 	}
 }
+
+func TestParseRewrites(t *testing.T) {
+	serviceName := "coffee-svc"
+	serviceNamePart := "serviceName=" + serviceName
+	rewritePath := "/beans/"
+	rewritePathPart := "rewrite=" + rewritePath
+	rewriteService := serviceNamePart + " " + rewritePathPart
+
+	serviceNameActual, rewritePathActual, err := parseRewrites(rewriteService)
+	if serviceName != serviceNameActual || rewritePath != rewritePathActual || err != nil {
+		t.Errorf("parseRewrites(%s) should return %q, %q, nil; got %q, %q, %v", rewriteService, serviceName, rewritePath, serviceNameActual, rewritePathActual, err)
+	}
+}
+
+func TestParseRewritesInvalidFormat(t *testing.T) {
+	rewriteService := "serviceNamecoffee-svc rewrite=/"
+
+	_, _, err := parseRewrites(rewriteService)
+	if err == nil {
+		t.Errorf("parseRewrites(%s) should return error, got nil", rewriteService)
+	}
+}

nginx-controller/nginx/ingress.tmpl

@@ -40,9 +40,9 @@ server {
 		proxy_set_header X-Forwarded-Port $server_port;
 		proxy_set_header X-Forwarded-Proto $scheme;
 		{{if $location.SSL}}
-		proxy_pass https://{{$location.Upstream.Name}};
+		proxy_pass https://{{$location.Upstream.Name}}{{$location.Rewrite}};
 		{{else}}
-		proxy_pass http://{{$location.Upstream.Name}};
+		proxy_pass http://{{$location.Upstream.Name}}{{$location.Rewrite}};
 		{{end}}
 	}{{end}}
 }{{end}}

nginx-controller/nginx/nginx.go

@@ -53,6 +53,7 @@ type Location struct {
 	ProxyReadTimeout    string
 	ClientMaxBodySize   string
 	Websocket           bool
+	Rewrite             string
 	SSL                 bool
 }
 

nginx-plus-controller/nginx/configurator.go

@@ -87,6 +87,7 @@ func (cnf *Configurator) generateNginxCfg(ingEx *IngressEx, pems map[string]stri
 
 	wsServices := getWebsocketServices(ingEx)
 	spServices := getSessionPersistenceServices(ingEx)
+	rewrites := getRewrites(ingEx)
 	sslServices := getSSLServices(ingEx)
 
 	if ingEx.Ingress.Spec.Backend != nil {
@@ -129,7 +130,7 @@ func (cnf *Configurator) generateNginxCfg(ingEx *IngressEx, pems map[string]stri
 				upstreams[upsName] = upstream
 			}
 
-			loc := createLocation(pathOrDefault(path.Path), upstreams[upsName], &ingCfg, wsServices[path.Backend.ServiceName], sslServices[path.Backend.ServiceName])
+			loc := createLocation(pathOrDefault(path.Path), upstreams[upsName], &ingCfg, wsServices[path.Backend.ServiceName], rewrites[path.Backend.ServiceName], sslServices[path.Backend.ServiceName])
 			locations = append(locations, loc)
 
 			if loc.Path == "/" {
@@ -139,7 +140,7 @@ func (cnf *Configurator) generateNginxCfg(ingEx *IngressEx, pems map[string]stri
 
 		if rootLocation == false && ingEx.Ingress.Spec.Backend != nil {
 			upsName := getNameForUpstream(ingEx.Ingress, emptyHost, ingEx.Ingress.Spec.Backend.ServiceName)
-			loc := createLocation(pathOrDefault("/"), upstreams[upsName], &ingCfg, wsServices[ingEx.Ingress.Spec.Backend.ServiceName], sslServices[ingEx.Ingress.Spec.Backend.ServiceName])
+			loc := createLocation(pathOrDefault("/"), upstreams[upsName], &ingCfg, wsServices[ingEx.Ingress.Spec.Backend.ServiceName], rewrites[ingEx.Ingress.Spec.Backend.ServiceName], sslServices[ingEx.Ingress.Spec.Backend.ServiceName])
 			locations = append(locations, loc)
 		}
 
@@ -164,7 +165,7 @@ func (cnf *Configurator) generateNginxCfg(ingEx *IngressEx, pems map[string]stri
 
 		upsName := getNameForUpstream(ingEx.Ingress, emptyHost, ingEx.Ingress.Spec.Backend.ServiceName)
 
-		loc := createLocation(pathOrDefault("/"), upstreams[upsName], &ingCfg, wsServices[ingEx.Ingress.Spec.Backend.ServiceName], sslServices[ingEx.Ingress.Spec.Backend.ServiceName])
+		loc := createLocation(pathOrDefault("/"), upstreams[upsName], &ingCfg, wsServices[ingEx.Ingress.Spec.Backend.ServiceName], rewrites[ingEx.Ingress.Spec.Backend.ServiceName], sslServices[ingEx.Ingress.Spec.Backend.ServiceName])
 		locations = append(locations, loc)
 
 		server.Locations = locations
@@ -201,6 +202,42 @@ func getWebsocketServices(ingEx *IngressEx) map[string]bool {
 	return wsServices
 }
 
+func getRewrites(ingEx *IngressEx) map[string]string {
+	rewrites := make(map[string]string)
+
+	if services, exists := ingEx.Ingress.Annotations["nginx.org/rewrites"]; exists {
+		for _, svc := range strings.Split(services, ";") {
+			if serviceName, rewrite, err := parseRewrites(svc); err != nil {
+				glog.Errorf("In %v nginx.org/rewrites contains invalid declaration: %v, ignoring", ingEx.Ingress.Name, err)
+			} else {
+				rewrites[serviceName] = rewrite
+			}
+		}
+	}
+
+	return rewrites
+}
+
+func parseRewrites(service string) (serviceName string, rewrite string, err error) {
+	parts := strings.SplitN(service, " ", 2)
+
+	if len(parts) != 2 {
+		return "", "", fmt.Errorf("Invalid rewrite format: %s\n", service)
+	}
+
+	svcNameParts := strings.Split(parts[0], "=")
+	if len(svcNameParts) != 2 {
+		return "", "", fmt.Errorf("Invalid rewrite format: %s\n", svcNameParts)
+	}
+
+	rwPathParts := strings.Split(parts[1], "=")
+	if len(rwPathParts) != 2 {
+		return "", "", fmt.Errorf("Invalid rewrite format: %s\n", rwPathParts)
+	}
+
+	return svcNameParts[1], rwPathParts[1], nil
+}
+
 func getSSLServices(ingEx *IngressEx) map[string]bool {
 	sslServices := make(map[string]bool)
 
@@ -244,14 +281,15 @@ func parseStickyService(service string) (serviceName string, stickyCookie string
 	return svcNameParts[1], parts[1], nil
 }
 
-func createLocation(path string, upstream Upstream, cfg *Config, websocket bool, ssl bool) Location {
+func createLocation(path string, upstream Upstream, cfg *Config, websocket bool, rewrite string, ssl bool) Location {
 	loc := Location{
 		Path:                path,
 		Upstream:            upstream,
 		ProxyConnectTimeout: cfg.ProxyConnectTimeout,
 		ProxyReadTimeout:    cfg.ProxyReadTimeout,
 		ClientMaxBodySize:   cfg.ClientMaxBodySize,
 		Websocket:           websocket,
+		Rewrite:             rewrite,
 		SSL:                 ssl,
 	}
 

nginx-plus-controller/nginx/configurator_test.go

@@ -19,6 +19,28 @@ func TestPathOrDefaultReturnActual(t *testing.T) {
 	}
 }
 
+func TestParseRewrites(t *testing.T) {
+	serviceName := "coffee-svc"
+	serviceNamePart := "serviceName=" + serviceName
+	rewritePath := "/beans/"
+	rewritePathPart := "rewrite=" + rewritePath
+	rewriteService := serviceNamePart + " " + rewritePathPart
+
+	serviceNameActual, rewritePathActual, err := parseRewrites(rewriteService)
+	if serviceName != serviceNameActual || rewritePath != rewritePathActual || err != nil {
+		t.Errorf("parseRewrites(%s) should return %q, %q, nil; got %q, %q, %v", rewriteService, serviceName, rewritePath, serviceNameActual, rewritePathActual, err)
+	}
+}
+
+func TestParseRewritesInvalidFormat(t *testing.T) {
+	rewriteService := "serviceNamecoffee-svc rewrite=/"
+
+	_, _, err := parseRewrites(rewriteService)
+	if err == nil {
+		t.Errorf("parseRewrites(%s) should return error, got nil", rewriteService)
+	}
+}
+
 func TestParseStickyService(t *testing.T) {
 	serviceName := "coffee-svc"
 	serviceNamePart := "serviceName=" + serviceName

nginx-plus-controller/nginx/ingress.tmpl

@@ -45,9 +45,9 @@ server {
 		proxy_set_header X-Forwarded-Port $server_port;
 		proxy_set_header X-Forwarded-Proto $scheme;
 		{{if $location.SSL}}
-		proxy_pass https://{{$location.Upstream.Name}};
+		proxy_pass https://{{$location.Upstream.Name}}{{$location.Rewrite}};
 		{{else}}
-		proxy_pass http://{{$location.Upstream.Name}};
+		proxy_pass http://{{$location.Upstream.Name}}{{$location.Rewrite}};
 		{{end}}
 	}{{end}}
 }{{end}}

nginx-plus-controller/nginx/nginx.go

@@ -76,6 +76,7 @@ type Location struct {
 	ProxyReadTimeout    string
 	ClientMaxBodySize   string
 	Websocket           bool
+	Rewrite             string
 	SSL                 bool
 }