Add /system/info endpoint for faas-swarm

The purpose of this change is to make faas-swarm compatible with the
latest version of the API Gateway in OpenFaaS. Each provider should
be able to advertise the underlying provider and the version of the
code.

A new version of faas-provider (0.6) is vendored into the repo
which brings in an optional health endpoint (turned off by default).

The version and SHA is being passed to the provider from server.go.
Dockerfiles are updated to inject version and SHA string at build time in
version.go.

A unit test has been added for the /system/info endpoint.

Signed-off-by: Vivek Singh <[email protected]>

Dockerfile

@@ -5,17 +5,19 @@ RUN mkdir -p /go/src/github.com/openfaas/faas-swarm/
 
 WORKDIR /go/src/github.com/openfaas/faas-swarm
 
-COPY vendor     vendor
-COPY handlers	  handlers
-COPY types      types
-COPY server.go  .
+COPY . .
 
 RUN curl -sL https://github.com/alexellis/license-check/releases/download/0.2.2/license-check > /usr/bin/license-check \
     && chmod +x /usr/bin/license-check
 RUN license-check -path ./ --verbose=false "Alex Ellis" "OpenFaaS Project"
 
 RUN gofmt -l -d $(find . -type f -name '*.go' -not -path "./vendor/*") \
-  && CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o faas-swarm .
+    && VERSION=$(git describe --all --exact-match `git rev-parse HEAD` | grep tags | sed 's/tags\///') \
+    && GIT_COMMIT=$(git rev-list -1 HEAD) \
+    && CGO_ENABLED=0 GOOS=linux go build --ldflags "-s -w \
+    -X github.com/openfaas/faas-swarm/version.GitCommit=${GIT_COMMIT}\
+    -X github.com/openfaas/faas-swarm/version.Version=${VERSION}" \
+    -a -installsuffix cgo -o faas-swarm .
 
 # Release stage
 FROM alpine:3.6

Dockerfile.armhf

@@ -5,18 +5,19 @@ RUN mkdir -p /go/src/github.com/openfaas/faas-swarm/
 
 WORKDIR /go/src/github.com/openfaas/faas-swarm
 
-COPY vendor     vendor
-COPY handlers	handlers
-COPY types      types
-
-COPY server.go  .
+COPY . .
 
 #RUN curl -sL https://github.com/alexellis/license-check/releases/download/0.2.2/license-check > /usr/bin/license-check \
 #    && chmod +x /usr/bin/license-check
 #RUN license-check -path ./ --verbose=false "Alex Ellis" "OpenFaaS Project"
 
 RUN gofmt -l -d $(find . -type f -name '*.go' -not -path "./vendor/*") \
-  && GOARM=6 CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o faas-swarm .
+  && VERSION=$(git describe --all --exact-match `git rev-parse HEAD` | grep tags | sed 's/tags\///') \
+  && GIT_COMMIT=$(git rev-list -1 HEAD) \
+  && GOARM=6 CGO_ENABLED=0 GOOS=linux go build --ldflags "-s -w \
+  -X github.com/openfaas/faas-swarm/version.GitCommit=${GIT_COMMIT}\
+  -X github.com/openfaas/faas-swarm/version.Version=${VERSION}" \
+  -a -installsuffix cgo -o faas-swarm .
 
 # Release stage
 FROM alpine:3.6

Gopkg.toml

@@ -16,7 +16,7 @@
 
 [[constraint]]
   name = "github.com/openfaas/faas-provider"
-  version = "0.5.0"
+  version = "0.6.0"
 
 # match docker/distribution revision with moby
 [[override]]

handlers/info.go

@@ -0,0 +1,43 @@
+package handlers
+
+import (
+	"encoding/json"
+	"net/http"
+
+	"github.com/openfaas/faas-provider/types"
+)
+
+const (
+	//SwarmIdentifier identifier string for swarm provider
+	SwarmIdentifier = "swarm"
+	//SwarmProvider provider string for swarm provider
+	SwarmProvider = "faas-swarm"
+)
+
+//MakeInfoHandler creates handler for /system/info endpoint
+func MakeInfoHandler(version, sha string) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		if r.Body != nil {
+			defer r.Body.Close()
+		}
+
+		infoRequest := types.InfoRequest{
+			Orchestration: SwarmIdentifier,
+			Provider:      SwarmProvider,
+			Version: types.ProviderVersion{
+				Release: version,
+				SHA:     sha,
+			},
+		}
+
+		jsonOut, marshalErr := json.Marshal(infoRequest)
+		if marshalErr != nil {
+			w.WriteHeader(http.StatusInternalServerError)
+			return
+		}
+
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(http.StatusOK)
+		w.Write(jsonOut)
+	}
+}

server.go

@@ -14,6 +14,7 @@ import (
 	bootTypes "github.com/openfaas/faas-provider/types"
 	"github.com/openfaas/faas-swarm/handlers"
 	"github.com/openfaas/faas-swarm/types"
+	"github.com/openfaas/faas-swarm/version"
 )
 
 func main() {
@@ -52,6 +53,7 @@ func main() {
 		ReplicaUpdater: handlers.ReplicaUpdater(dockerClient),
 		UpdateHandler:  handlers.UpdateHandler(dockerClient, maxRestarts, restartDelay),
 		Health:         handlers.Health(),
+		InfoHandler:    handlers.MakeInfoHandler(version.BuildVersion(), version.GitCommit),
 	}
 
 	bootstrapConfig := bootTypes.FaaSConfig{

test/info_test.go

@@ -0,0 +1,60 @@
+package test
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/openfaas/faas-provider/types"
+	"github.com/openfaas/faas-swarm/handlers"
+)
+
+const (
+	infoTestVersion = "swarmtest"
+	infoTestSHA     = "test"
+)
+
+func TestMakeInfoHandler(t *testing.T) {
+	rr := httptest.NewRecorder()
+
+	req, err := http.NewRequest("GET", "/system/info", nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	handler := handlers.MakeInfoHandler(infoTestVersion, infoTestSHA)
+	infoRequest := types.InfoRequest{}
+
+	handler(rr, req)
+	body, err := ioutil.ReadAll(rr.Body)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = json.Unmarshal(body, &infoRequest)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if required := http.StatusOK; rr.Code != required {
+		t.Errorf("handler returned wrong status code - want: %v, got: %v", required, rr.Code)
+	}
+
+	if infoRequest.Orchestration != handlers.SwarmIdentifier {
+		t.Errorf("handler returned wrong orchestration - want: %v, got: %v", handlers.SwarmIdentifier, infoRequest.Orchestration)
+	}
+
+	if infoRequest.Provider != handlers.SwarmProvider {
+		t.Errorf("handler returned wrong provider - want: %v, got: %v", handlers.SwarmProvider, infoRequest.Provider)
+	}
+
+	if infoRequest.Version.Release != infoTestVersion {
+		t.Errorf("handler returned wrong release version - want: %v, got: %v", infoTestVersion, infoRequest.Version.Release)
+	}
+
+	if infoRequest.Version.SHA != infoTestSHA {
+		t.Errorf("handler returned wrong SHA string - want: %v, got: %v", infoTestSHA, infoRequest.Version.SHA)
+	}
+}

version/version.go

@@ -0,0 +1,18 @@
+package version
+
+var (
+	//Version release version of the provider
+	Version string
+	//GitCommit SHA of the last git commit
+	GitCommit string
+	//DevVerison string for the development version
+	DevVerison = "dev"
+)
+
+//BuildVersion returns current version of the provider
+func BuildVersion() string {
+	if len(Version) == 0 {
+		return DevVerison
+	}
+	return Version
+}