[FAB-15814] Add endpoint for versioning metadata

Adds a /version endpoint to the operations
server that serves the Version and CommitSHA
from the common/metadata package

Change-Id: Ic16e044f989bf9bdf827637412217fb07a8394e3
Signed-off-by: Brett Logan <Brett.T.Logan@ibm.com>
(cherry picked from commit b66fc33)

core/operations/system.go

@@ -19,6 +19,7 @@ import (
 	"github.com/hyperledger/fabric-lib-go/healthz"
 	"github.com/hyperledger/fabric/common/flogging"
 	"github.com/hyperledger/fabric/common/flogging/httpadmin"
+	"github.com/hyperledger/fabric/common/metadata"
 	"github.com/hyperledger/fabric/common/metrics"
 	"github.com/hyperledger/fabric/common/metrics/disabled"
 	"github.com/hyperledger/fabric/common/metrics/prometheus"
@@ -86,6 +87,7 @@ func NewSystem(o Options) *System {
 	system.initializeHealthCheckHandler()
 	system.initializeLoggingHandler()
 	system.initializeMetricsProvider()
+	system.initializeVersionInfoHandler()
 
 	return system
 }
@@ -201,6 +203,14 @@ func (s *System) initializeHealthCheckHandler() {
 	s.mux.Handle("/healthz", s.handlerChain(s.healthHandler, false))
 }
 
+func (s *System) initializeVersionInfoHandler() {
+	versionInfo := &VersionInfoHandler{
+		CommitSHA: metadata.CommitSHA,
+		Version:   metadata.Version,
+	}
+	s.mux.Handle("/version", s.handlerChain(versionInfo, false))
+}
+
 func (s *System) startMetricsTickers() error {
 	m := s.options.Metrics
 	if s.statsd != nil {

core/operations/system_test.go

@@ -78,6 +78,17 @@ var _ = Describe("System", func() {
 		}
 	})
 
+	It("hosts an unsecured endpoint for the version information", func() {
+		err := system.Start()
+		Expect(err).NotTo(HaveOccurred())
+
+		versionURL := fmt.Sprintf("https://%s/version", system.Addr())
+		resp, err := client.Get(versionURL)
+		Expect(err).NotTo(HaveOccurred())
+		Expect(resp.StatusCode).To(Equal(http.StatusOK))
+		resp.Body.Close()
+	})
+
 	It("hosts a secure endpoint for logging", func() {
 		err := system.Start()
 		Expect(err).NotTo(HaveOccurred())

core/operations/version.go

@@ -0,0 +1,50 @@
+/*
+Copyright IBM Corp All Rights Reserved.
+
+SPDX-License-Identifier: Apache-2.0
+*/
+
+package operations
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+
+	"github.com/hyperledger/fabric/common/flogging"
+)
+
+type VersionInfoHandler struct {
+	CommitSHA string `json:"CommitSHA,omitempty"`
+	Version   string `json:"Version,omitempty"`
+}
+
+func (m *VersionInfoHandler) ServeHTTP(resp http.ResponseWriter, req *http.Request) {
+	switch req.Method {
+	case http.MethodGet:
+		m.sendResponse(resp, http.StatusOK, m)
+	default:
+		err := fmt.Errorf("invalid request method: %s", req.Method)
+		m.sendResponse(resp, http.StatusBadRequest, err)
+	}
+}
+
+type errorResponse struct {
+	Error string `json:"Error"`
+}
+
+func (m *VersionInfoHandler) sendResponse(resp http.ResponseWriter, code int, payload interface{}) {
+	if err, ok := payload.(error); ok {
+		payload = &errorResponse{Error: err.Error()}
+	}
+	js, err := json.Marshal(payload)
+	if err != nil {
+		logger := flogging.MustGetLogger("operations.runner")
+		logger.Errorw("failed to encode payload", "error", err)
+		resp.WriteHeader(http.StatusInternalServerError)
+	} else {
+		resp.WriteHeader(code)
+		resp.Header().Set("Content-Type", "application/json")
+		resp.Write(js)
+	}
+}

core/operations/version_test.go

@@ -0,0 +1,43 @@
+/*
+Copyright IBM Corp All Rights Reserved.
+
+SPDX-License-Identifier: Apache-2.0
+*/
+
+package operations
+
+import (
+	"net/http"
+	"net/http/httptest"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("Version", func() {
+	It("returns 200 if the method is GET", func() {
+		resp := httptest.NewRecorder()
+
+		versionInfoHandler := &VersionInfoHandler{Version: "latest"}
+		versionInfoHandler.ServeHTTP(resp, &http.Request{Method: http.MethodGet})
+		Expect(resp.Result().StatusCode).To(Equal(http.StatusOK))
+		Expect(resp.Body).To(MatchJSON(`{"Version": "latest"}`))
+	})
+
+	It("returns 400 when an unsupported method is used", func() {
+		resp := httptest.NewRecorder()
+
+		versionInfoHandler := &VersionInfoHandler{}
+		versionInfoHandler.ServeHTTP(resp, &http.Request{Method: http.MethodPut})
+		Expect(resp.Result().StatusCode).To(Equal(http.StatusBadRequest))
+		Expect(resp.Body).To(MatchJSON(`{"Error": "invalid request method: PUT"}`))
+	})
+
+	It("returns 500 when the payload is invalid JSON", func() {
+		resp := httptest.NewRecorder()
+
+		versionInfoHandler := &VersionInfoHandler{}
+		versionInfoHandler.sendResponse(resp, 200, make(chan int))
+		Expect(resp.Result().StatusCode).To(Equal(http.StatusInternalServerError))
+	})
+})