Support external URL for FaaS functions

docker-compose.yml

@@ -7,7 +7,7 @@ services:
             - "/var/run/docker.sock:/var/run/docker.sock"
         ports:
             - 8080:8080
-        image: functions/gateway:0.5.6
+        image: functions/gateway:latest-dev
         networks:
             - functions
         environment:

gateway/Dockerfile.build

@@ -1,13 +1,5 @@
 FROM golang:1.7.5
 
-#RUN go get -d github.com/docker/docker/api/types \
-#   && go get -d github.com/docker/docker/api/types/filters \
-#   && go get -d github.com/docker/docker/api/types/swarm \
-#   && go get -d github.com/docker/docker/client \
-#   && go get github.com/gorilla/mux \
-#   && go get github.com/prometheus/client_golang/prometheus
-#RUN go get -d github.com/Sirupsen/logrus
-
 WORKDIR /go/src/github.com/alexellis/faas/gateway
 
 COPY vendor         vendor
@@ -17,7 +9,7 @@ COPY metrics        metrics
 COPY requests       requests
 COPY tests          tests
 COPY server.go      .
-COPY readconfig.go  .
+COPY types          types
 
 RUN go test -v ./tests && \
     CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o app .

gateway/Dockerfile.build.armhf

@@ -16,7 +16,7 @@ COPY tests          tests
 COPY handlers       handlers
 
 COPY server.go      .
-COPY readconfig.go  .
+COPY types          types
 
 RUN go test -v ./tests && \
     CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o app .

gateway/Dockerfile.multistage

@@ -8,7 +8,7 @@ COPY metrics        metrics
 COPY requests       requests
 COPY tests          tests
 COPY server.go      .
-COPY readconfig.go  .
+COPY types          types
 
 RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o gateway .
 

gateway/Dockerfile.newbuild

@@ -9,7 +9,7 @@ COPY metrics        metrics
 COPY requests       requests
 COPY tests          tests
 COPY server.go      .
-COPY readconfig.go  .
+COPY types          types
 
 RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o gateway .
 

gateway/handlers/externalprovider.go

@@ -0,0 +1 @@
+package handlers

gateway/server.go

@@ -4,29 +4,44 @@ import (
 	"context"
 	"log"
 	"net/http"
-
+	"net/http/httputil"
-	"github.com/Sirupsen/logrus"
-	faasHandlers "github.com/alexellis/faas/gateway/handlers"
-	"github.com/alexellis/faas/gateway/metrics"
-	"github.com/docker/docker/client"
 
 	"fmt"
 
+	"github.com/Sirupsen/logrus"
+	internalHandlers "github.com/alexellis/faas/gateway/handlers"
+	"github.com/alexellis/faas/gateway/metrics"
+	"github.com/alexellis/faas/gateway/types"
+	"github.com/docker/docker/client"
+
 	"github.com/gorilla/mux"
 )
 
+type handlerSet struct {
+	Proxy          http.HandlerFunc
+	DeployFunction http.HandlerFunc
+	DeleteFunction http.HandlerFunc
+	ListFunctions  http.HandlerFunc
+	Alert          http.HandlerFunc
+	RoutelessProxy http.HandlerFunc
+}
+
 func main() {
 	logger := logrus.Logger{}
 	logrus.SetFormatter(&logrus.TextFormatter{})
 
-	osEnv := OsEnv{}
+	osEnv := types.OsEnv{}
-	readConfig := ReadConfig{}
+	readConfig := types.ReadConfig{}
 	config := readConfig.Read(osEnv)
 
 	log.Printf("HTTP Read Timeout: %s", config.ReadTimeout)
 	log.Printf("HTTP Write Timeout: %s", config.WriteTimeout)
 
 	var dockerClient *client.Client
+
+	if config.UseExternalProvider() {
+		log.Printf("Binding to external function provider: %s", config.FunctionsProviderURL)
+	} else {
 		var err error
 		dockerClient, err = client.NewEnvClient()
 		if err != nil {
@@ -37,34 +52,55 @@ func main() {
 			log.Fatal("Error with Docker server.\n", err)
 		}
 		log.Printf("Docker API version: %s, %s\n", dockerVersion.APIVersion, dockerVersion.Version)
+	}
 
 	metricsOptions := metrics.BuildMetricsOptions()
 	metrics.RegisterMetrics(metricsOptions)
 
-	r := mux.NewRouter()
+	var faasHandlers handlerSet
-	// r.StrictSlash(false)	// This didn't work, so register routes twice.
 
-	functionHandler := faasHandlers.MakeProxy(metricsOptions, true, dockerClient, &logger)
+	if config.UseExternalProvider() {
-	r.HandleFunc("/function/{name:[-a-zA-Z_0-9]+}", functionHandler)
-	r.HandleFunc("/function/{name:[-a-zA-Z_0-9]+}/", functionHandler)
 
-	r.HandleFunc("/system/alert", faasHandlers.MakeAlertHandler(dockerClient))
+		reverseProxy := httputil.NewSingleHostReverseProxy(config.FunctionsProviderURL)
-	r.HandleFunc("/system/functions", faasHandlers.MakeFunctionReader(metricsOptions, dockerClient)).Methods("GET")
-	r.HandleFunc("/system/functions", faasHandlers.MakeNewFunctionHandler(metricsOptions, dockerClient)).Methods("POST")
-	r.HandleFunc("/system/functions", faasHandlers.MakeDeleteFunctionHandler(metricsOptions, dockerClient)).Methods("DELETE")
 
-	fs := http.FileServer(http.Dir("./assets/"))
+		faasHandlers.Proxy = handler(reverseProxy)
-	r.PathPrefix("/ui/").Handler(http.StripPrefix("/ui", fs)).Methods("GET")
+		faasHandlers.RoutelessProxy = handler(reverseProxy)
+		faasHandlers.Alert = handler(reverseProxy)
+		faasHandlers.ListFunctions = handler(reverseProxy)
+		faasHandlers.DeployFunction = handler(reverseProxy)
+		faasHandlers.DeleteFunction = handler(reverseProxy)
 
-	r.HandleFunc("/", faasHandlers.MakeProxy(metricsOptions, false, dockerClient, &logger)).Methods("POST")
+	} else {
-
+		faasHandlers.Proxy = internalHandlers.MakeProxy(metricsOptions, true, dockerClient, &logger)
-	metricsHandler := metrics.PrometheusHandler()
+		faasHandlers.RoutelessProxy = internalHandlers.MakeProxy(metricsOptions, true, dockerClient, &logger)
-	r.Handle("/metrics", metricsHandler)
+		faasHandlers.Alert = internalHandlers.MakeAlertHandler(dockerClient)
+		faasHandlers.ListFunctions = internalHandlers.MakeFunctionReader(metricsOptions, dockerClient)
+		faasHandlers.DeployFunction = internalHandlers.MakeNewFunctionHandler(metricsOptions, dockerClient)
+		faasHandlers.DeleteFunction = internalHandlers.MakeDeleteFunctionHandler(metricsOptions, dockerClient)
 
 		// This could exist in a separate process - records the replicas of each swarm service.
 		functionLabel := "function"
 		metrics.AttachSwarmWatcher(dockerClient, metricsOptions, functionLabel)
+	}
 
+	r := mux.NewRouter()
+
+	// r.StrictSlash(false)	// This didn't work, so register routes twice.
+	r.HandleFunc("/function/{name:[-a-zA-Z_0-9]+}", faasHandlers.Proxy)
+	r.HandleFunc("/function/{name:[-a-zA-Z_0-9]+}/", faasHandlers.Proxy)
+
+	r.HandleFunc("/system/alert", faasHandlers.Alert)
+	r.HandleFunc("/system/functions", faasHandlers.ListFunctions).Methods("GET")
+	r.HandleFunc("/system/functions", faasHandlers.DeployFunction).Methods("POST")
+	r.HandleFunc("/system/functions", faasHandlers.DeleteFunction).Methods("DELETE")
+
+	fs := http.FileServer(http.Dir("./assets/"))
+	r.PathPrefix("/ui/").Handler(http.StripPrefix("/ui", fs)).Methods("GET")
+
+	r.HandleFunc("/", faasHandlers.RoutelessProxy).Methods("POST")
+
+	metricsHandler := metrics.PrometheusHandler()
+	r.Handle("/metrics", metricsHandler)
 	r.Handle("/", http.RedirectHandler("/ui/", http.StatusMovedPermanently)).Methods("GET")
 
 	tcpPort := 8080
@@ -79,3 +115,10 @@ func main() {
 
 	log.Fatal(s.ListenAndServe())
 }
+
+func handler(p *httputil.ReverseProxy) func(http.ResponseWriter, *http.Request) {
+	return func(w http.ResponseWriter, r *http.Request) {
+		log.Printf("Forwarding [%s] to %s", r.Method, r.URL.String())
+		p.ServeHTTP(w, r)
+	}
+}

gateway/tests/config_test.go

@@ -7,7 +7,7 @@ import (
 	"testing"
 	"time"
 
-	gateway "github.com/alexellis/faas/gateway"
+	"github.com/alexellis/faas/gateway/types"
 )
 
 type EnvBucket struct {
@@ -28,9 +28,21 @@ func (e EnvBucket) Setenv(key string, value string) {
 	e.Items[key] = value
 }
 
+func TestRead_UseExternalProvider_Defaults(t *testing.T) {
+	defaults := NewEnvBucket()
+	readConfig := types.ReadConfig{}
+
+	config := readConfig.Read(defaults)
+
+	if config.UseExternalProvider() != false {
+		t.Log("Default for UseExternalProvider should be false")
+		t.Fail()
+	}
+}
+
 func TestRead_EmptyTimeoutConfig(t *testing.T) {
 	defaults := NewEnvBucket()
-	readConfig := gateway.ReadConfig{}
+	readConfig := types.ReadConfig{}
 
 	config := readConfig.Read(defaults)
 
@@ -49,7 +61,7 @@ func TestRead_ReadAndWriteTimeoutConfig(t *testing.T) {
 	defaults.Setenv("read_timeout", "10")
 	defaults.Setenv("write_timeout", "60")
 
-	readConfig := gateway.ReadConfig{}
+	readConfig := types.ReadConfig{}
 	config := readConfig.Read(defaults)
 
 	if (config.ReadTimeout) != time.Duration(10)*time.Second {

gateway/types/readconfig.go

@@ -1,6 +1,8 @@
-package main
+package types
 
 import (
+	"log"
+	"net/url"
 	"os"
 	"strconv"
 	"time"
@@ -51,6 +53,14 @@ func (ReadConfig) Read(hasEnv HasEnv) GatewayConfig {
 	cfg.ReadTimeout = time.Duration(readTimeout) * time.Second
 	cfg.WriteTimeout = time.Duration(writeTimeout) * time.Second
 
+	if len(hasEnv.Getenv("functions_provider_url")) > 0 {
+		var err error
+		cfg.FunctionsProviderURL, err = url.Parse(hasEnv.Getenv("functions_provider_url"))
+		if err != nil {
+			log.Fatal("If functions_provider_url is provided, then it should be a valid URL.", err)
+		}
+	}
+
 	return cfg
 }
 
@@ -58,4 +68,10 @@ func (ReadConfig) Read(hasEnv HasEnv) GatewayConfig {
 type GatewayConfig struct {
 	ReadTimeout          time.Duration
 	WriteTimeout         time.Duration
+	FunctionsProviderURL *url.URL
+}
+
+// UseExternalProvider decide whether to bypass built-in Docker Swarm engine
+func (g *GatewayConfig) UseExternalProvider() bool {
+	return g.FunctionsProviderURL != nil
 }