Add architecture to /system/info endpoint

With this change /system/info endpoint is going to give
information about the platform architecture it is running on
(arm64, armhf, x86_64)

Signed-off-by: Ivana Yovcheva (VMware) <iyovcheva@vmware.com>

api-docs/swagger.yml

@@ -434,6 +434,10 @@ definitions:
             type: string
             format: semver
             example: 0.8.9
+      arch:
+        type: string
+        description: "Platform architecture"
+        example: "x86_64"
     required:
     - provider
     - version

gateway/Dockerfile

@@ -2,6 +2,7 @@ FROM golang:1.10.4 as build
 ARG GIT_COMMIT_SHA
 ARG GIT_COMMIT_MESSAGE
 ARG VERSION='dev'
+ARG ARCH
 
 RUN curl -sLSf \
   https://raw.githubusercontent.com/teamserverless/license-check/master/get.sh | sh \
@@ -30,7 +31,8 @@ RUN license-check -path ./ --verbose=false "Alex Ellis" "OpenFaaS Project" "Open
     && CGO_ENABLED=0 GOOS=linux go build --ldflags "-s -w \
     -X github.com/openfaas/faas/gateway/version.GitCommitSHA=${GIT_COMMIT_SHA}\
     -X \"github.com/openfaas/faas/gateway/version.GitCommitMessage=${GIT_COMMIT_MESSAGE}\"\
-    -X github.com/openfaas/faas/gateway/version.Version=${VERSION}" \
+    -X \"github.com/openfaas/faas/gateway/version.Version=${VERSION}\" \
+    -X github.com/openfaas/faas/gateway/types.Arch=${ARCH}"\
     -a -installsuffix cgo -o gateway .
 
 FROM alpine:3.9

gateway/build.sh

@@ -9,7 +9,9 @@ export eTAG="latest-dev"
 if [ "$arch" = "armv7l" ] ; then
    dockerfile="Dockerfile.armhf"
    eTAG="latest-armhf-dev"
+   arch="armhf"
 elif [ "$arch" = "aarch64" ] ; then
+   arch="arm64"
    dockerfile="Dockerfile.arm64"
    eTAG="latest-arm64-dev"
 fi
@@ -35,4 +37,5 @@ VERSION=$(git describe --all --exact-match `git rev-parse HEAD` | grep tags | se
 docker build --build-arg https_proxy=$https_proxy --build-arg http_proxy=$http_proxy \
   --build-arg GIT_COMMIT_MESSAGE="$GIT_COMMIT_MESSAGE" --build-arg GIT_COMMIT_SHA=$GIT_COMMIT_SHA \
   --build-arg VERSION=${VERSION:-dev} \
+  --build-arg ARCH=$arch \
   -t $NS/gateway:$eTAG . -f $dockerfile --no-cache

gateway/handlers/infohandler.go

@@ -48,6 +48,7 @@ func MakeInfoHandler(h http.Handler) http.HandlerFunc {
 				Name:          provider["provider"].(string),
 				Orchestration: provider["orchestration"].(string),
 			},
+			Arch: types.Arch,
 		}
 
 		jsonOut, marshalErr := json.Marshal(gatewayInfo)

gateway/tests/integration/infohandler_test.go

@@ -46,3 +46,23 @@ func Test_InfoEndpoint_Returns_Gateway_Version_SHA_And_Message(t *testing.T) {
 		t.Errorf("length of commit message should be greater than 0. Json body was %s", body)
 	}
 }
+
+func Test_InfoEndpoint_Returns_Arch(t *testing.T) {
+	body, _, err := fireRequest("http://localhost:8080/system/info", http.MethodGet, "")
+
+	if err != nil {
+		t.Log(err)
+		t.Fail()
+	}
+
+	gatewayInfo := &types.GatewayInfo{}
+	err = json.Unmarshal([]byte(body), gatewayInfo)
+	if err != nil {
+		t.Errorf("Could not unmarshal gateway info, response body:%s, error:%s", body, err.Error())
+		t.Fail()
+	}
+
+	if len(gatewayInfo.Arch) == 0 {
+		t.Errorf("value of arch should be non-empty")
+	}
+}

gateway/types/inforequest.go

@@ -1,9 +1,13 @@
 package types
 
+// Platform architecture the gateway is running on
+var Arch string
+
 // GatewayInfo provides information about the gateway and it's connected components
 type GatewayInfo struct {
 	Provider *ProviderInfo `json:"provider"`
 	Version  *VersionInfo  `json:"version"`
+	Arch     string        `json:"arch"`
 }
 
 // ProviderInfo provides information about the configured provider