Add key-protected sample

sample-functions/ApiKeyProtected/.gitignore

+ApiKeyProtected
+

sample-functions/ApiKeyProtected/Dockerfile

+FROM alpine:latest
+
+WORKDIR /root/
+
+EXPOSE 8080
+ENV http_proxy      ""
+ENV https_proxy     ""
+
+# ADD https://github.com/alexellis/faas/releases/download/v0.5-alpha/fwatchdog /usr/bin
+COPY fwatchdog  /usr/bin/
+RUN chmod +x /usr/bin/fwatchdog
+
+COPY app    .
+
+ENV fprocess="/root/app"
+CMD ["fwatchdog"]

sample-functions/ApiKeyProtected/Dockerfile.build

+FROM golang:1.7.5
+RUN mkdir -p /go/src/app
+COPY handler.go /go/src/app
+WORKDIR /go/src/app
+
+RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o app .
+
+CMD ["echo"]
+

sample-functions/ApiKeyProtected/README.md

+### Api-Key-Protected sample
+
+To use this sample provide an env variable for the container/service in `secret_api_key`.
+
+Then when calling via the gateway pass the additional header "X-Api-Key", if it matches the `secret_api_key` value then the function will give access, otherwise access denied.
+

sample-functions/ApiKeyProtected/build.sh

+#!/bin/sh
+echo Building functions/api-key-protected:build
+
+docker build --build-arg https_proxy=$https_proxy --build-arg http_proxy=$http_proxy \
+    -t functions/api-key-protected . -f Dockerfile.build
+
+docker create --name render_extract functions/api-key-protected
+docker cp render_extract:/go/src/app/app ./app
+docker rm -f render_extract
+
+echo Building functions/api-key-protected:latest
+docker build --no-cache -t functions/api-key-protected:latest .

sample-functions/ApiKeyProtected/handler.go

+package main
+
+import (
+	"fmt"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"os"
+
+	"github.com/alexellis/faas/watchdog/types"
+)
+
+func handle(header http.Header, body []byte) {
+	key := header.Get("X-Api-Key")
+	if key == os.Getenv("secret_api_key") {
+		fmt.Println("Unlocked the function!")
+	} else {
+		fmt.Println("Access denied!")
+	}
+}
+
+func main() {
+	bytes, _ := ioutil.ReadAll(os.Stdin)
+	req, err := types.UnmarshalRequest(bytes)
+	if err != nil {
+		log.Fatal(err)
+	}
+	handle(req.Header, req.Body.Raw)
+}