Enable routing to Alexa functions

Add first Alexa-compatible function HostnameIntent

faas @ d94cfeb6

+Subproject commit d94cfeb660705028b6c101412a03519a8164712d

gateway/.gitignore

 gateway
+sample.txt

gateway/Dockerfile

 from golang:1.7.3
 
 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
-RUN go get github.com/gorilla/mux \
-    && go get github.com/prometheus/client_golang/prometheus
+   && 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
 
 WORKDIR /go/src/github.com/alexellis/faas/gateway
 

gateway/server.go

@@ -3,13 +3,16 @@ package main
 import (
 	"bytes"
 	"context"
+	"fmt"
 	"log"
 	"net/http"
+	"strconv"
+	"strings"
 	"time"
 
 	"io/ioutil"
 
-	"strconv"
+	"encoding/json"
 
 	"github.com/alexellis/faas/gateway/metrics"
 	"github.com/docker/docker/api/types"
@@ -19,6 +22,28 @@ import (
 	"github.com/prometheus/client_golang/prometheus"
 )
 
+type AlexaSessionApplication struct {
+	ApplicationId string `json:"applicationId"`
+}
+
+type AlexaSession struct {
+	SessionId   string                  `json:"sessionId"`
+	Application AlexaSessionApplication `json:"application"`
+}
+
+type AlexaIntent struct {
+	Name string `json:"name"`
+}
+
+type AlexaRequest struct {
+	Intent AlexaIntent `json:"intent"`
+}
+
+type AlexaRequestBody struct {
+	Session AlexaSession `json:"session"`
+	Request AlexaRequest `json:"request"`
+}
+
 func lookupSwarmService(serviceName string) (bool, error) {
 	var c *client.Client
 	var err error
@@ -33,38 +58,69 @@ func lookupSwarmService(serviceName string) (bool, error) {
 	return len(services) > 0, err
 }
 
+func isAlexa(requestBody []byte) AlexaRequestBody {
+	body := AlexaRequestBody{}
+	buf := bytes.NewBuffer(requestBody)
+	fmt.Println(buf)
+	str := buf.String()
+	parts := strings.Split(str, "sessionId")
+	if len(parts) > 0 {
+		json.Unmarshal(requestBody, &body)
+		fmt.Println("Alexa SDK request found")
+		fmt.Printf("Session=%s, Intent=%s, App=%s\n", body.Session.SessionId, body.Request.Intent, body.Session.Application.ApplicationId)
+	}
+	return body
+}
+
+func invokeService(w http.ResponseWriter, r *http.Request, metrics metrics.MetricOptions, service string, requestBody []byte) {
+	start := time.Now()
+	buf := bytes.NewBuffer(requestBody)
+	url := "http://" + service + ":" + strconv.Itoa(8080) + "/"
+	fmt.Println("Forwarding request to ", url)
+	response, err := http.Post(url, "text/plain", buf)
+	if err != nil {
+		log.Fatalln(err)
+	}
+
+	responseBody, _ := ioutil.ReadAll(response.Body)
+	w.Write(responseBody)
+	seconds := time.Since(start).Seconds()
+	fmt.Printf("Took %f\n", seconds)
+	metrics.GatewayServerlessServedTotal.Inc()
+	metrics.GatewayFunctions.Observe(seconds)
+}
+
 func makeProxy(metrics metrics.MetricOptions) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		metrics.GatewayRequestsTotal.Inc()
 
-		start := time.Now()
-
 		if r.Method == "POST" {
 			log.Println(r.Header)
 			header := r.Header["X-Function"]
 			log.Println(header)
 
-			exists, err := lookupSwarmService(header[0])
-			if err != nil {
-				log.Fatalln(err)
-			}
-
-			if exists == true {
-				requestBody, _ := ioutil.ReadAll(r.Body)
-				buf := bytes.NewBuffer(requestBody)
-
-				response, err := http.Post("http://"+header[0]+":"+strconv.Itoa(8080)+"/", "text/plain", buf)
+			if len(header) > 0 {
+				exists, err := lookupSwarmService(header[0])
 				if err != nil {
 					log.Fatalln(err)
 				}
-				responseBody, _ := ioutil.ReadAll(response.Body)
-				w.Write(responseBody)
-				metrics.GatewayServerlessServedTotal.Inc()
-
-				metrics.GatewayFunctions.Observe(time.Since(start).Seconds())
+				if exists == true {
+					requestBody, _ := ioutil.ReadAll(r.Body)
+					invokeService(w, r, metrics, header[0], requestBody)
+				}
 			} else {
-				w.WriteHeader(http.StatusBadRequest)
-				w.Write([]byte("Provide an x-function header."))
+				requestBody, _ := ioutil.ReadAll(r.Body)
+				alexaService := isAlexa(requestBody)
+				if len(alexaService.Session.SessionId) > 0 &&
+					len(alexaService.Session.Application.ApplicationId) > 0 &&
+					len(alexaService.Request.Intent.Name) > 0 {
+					fmt.Println("Alexa skill detected")
+					invokeService(w, r, metrics, alexaService.Request.Intent.Name, requestBody)
+
+				} else {
+					w.WriteHeader(http.StatusBadRequest)
+					w.Write([]byte("Provide an x-function header."))
+				}
 			}
 		}
 	}

oneshot.sh

+#!/bin/bash
+
+ docker network create --driver overlay --attachable functions
+ git clone https://github.com/alexellis/faas && cd faas
+ cd watchdog
+ ./build.sh
+ docker build -t catservice .
+ docker service rm catservice ; docker service create --network=functions --name catservice catservice
+ cd ..
+ cd gateway
+ docker build -t server . ;docker rm -f server; docker run -v /var/run/docker.sock:/var/run/docker.sock --name server -p 8080:8080 --network=functions server
+

sample-functions/HostnameIntent/Dockerfile

+FROM alpine:latest
+RUN apk --update add nodejs
+COPY ./fwatchdog /usr/bin/
+
+COPY package.json   .
+COPY handler.js     .
+COPY sample.json    .
+
+RUN npm i
+ENV fprocess="node handler.js"
+CMD ["fwatchdog"]

sample-functions/HostnameIntent/handler.js

+"use strict"
+let fs = require('fs');
+let sample = require("./sample.json");
+
+var content = '';
+process.stdin.resume();
+process.stdin.on('data', function(buf) { content += buf.toString(); });
+process.stdin.on('end', function() {
+    fs.readFile("/etc/hostname", "utf8", (err, data) => {
+      if(err) {
+        return console.log(err);
+      }
+//      console.log(content);
+
+      sample.response.outputSpeech.text = "Your hostname is: " + data;
+      sample.response.card.content = "Your hostname is: "+ data
+      sample.response.card.title = "Your hostname";
+      console.log(JSON.stringify(sample));
+      process.exit(0);
+   });
+});
+

sample-functions/HostnameIntent/package.json

+{
+  "name": "HostnameIntent",
+  "version": "1.0.0",
+  "description": "",
+  "main": "handler.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC"
+}

sample-functions/HostnameIntent/sample.json

+{
+  "version": "1.0",
+  "response": {
+    "outputSpeech": {
+      "type": "PlainText",
+      "text": "There's currently 6 people in space"
+    },
+    "card": {
+      "content": "There's currently 6 people in space",
+      "title": "People in space",
+      "type": "Simple"
+    },
+    "shouldEndSession": true
+  },
+  "sessionAttributes": {}
+}