Improve user agent and version handling in chart-repo command (#558)

Author: migmartri

.circleci/config.yml

@@ -110,7 +110,13 @@ jobs:
       - run: |
           CMDS=(chart-repo chartsvc)
           for CMD in ${CMDS[@]}; do
-            make -C cmd/${CMD} docker-build
+            # If we are in a release we pass the version to the build process to bake the version
+            # By default, if no passed it will use the commit sha
+            if [[ -n "${CIRCLE_TAG}" ]]; then
+              makeArgs="VERSION=${CIRCLE_TAG}"
+            fi
+
+            make -C cmd/${CMD} $makeArgs docker-build
           done
 
           if [[ -z "${CIRCLE_PULL_REQUEST}" && -n "${DOCKER_USERNAME}" && -n "${DOCKER_PASSWORD}" ]] && [[ "${CIRCLE_BRANCH}" == "master" || -n "${CIRCLE_TAG}" ]]; then

cmd/chart-repo/Dockerfile

@@ -1,7 +1,9 @@
 FROM golang:1.11 as builder
 COPY . /go/src/github.com/helm/monocular
 WORKDIR /go/src/github.com/helm/monocular
-RUN CGO_ENABLED=0 go build -a -installsuffix cgo ./cmd/chart-repo
+
+ARG VERSION
+RUN CGO_ENABLED=0 go build -a -installsuffix cgo -ldflags "-X main.version=$VERSION" ./cmd/chart-repo
 
 FROM scratch
 COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/

cmd/chart-repo/Makefile

@@ -1,6 +1,8 @@
 IMAGE_REPO ?= quay.io/helmpack/chart-repo
 IMAGE_TAG ?= latest
+# Version of the binary to be produced
+VERSION ?= $$(git rev-parse HEAD)
 
 docker-build:
 	# We use the context of the root dir
-	docker build --pull --rm -t ${IMAGE_REPO}:${IMAGE_TAG} -f Dockerfile ../../
+	docker build --pull --rm -t ${IMAGE_REPO}:${IMAGE_TAG} --build-arg "VERSION=${VERSION}" -f Dockerfile ../../

cmd/chart-repo/chart_repo.go

@@ -24,7 +24,7 @@ import (
 
 var rootCmd = &cobra.Command{
 	Use:   "chart-repo",
-	Short: "Kubeapps Chart Repository utility",
+	Short: "Chart Repository utility",
 	Run: func(cmd *cobra.Command, args []string) {
 		cmd.Help()
 	},
@@ -45,6 +45,9 @@ func init() {
 		cmd.Flags().String("mongo-url", "localhost", "MongoDB URL (see https://godoc.org/github.com/globalsign/mgo#Dial for format)")
 		cmd.Flags().String("mongo-database", "charts", "MongoDB database")
 		cmd.Flags().String("mongo-user", "", "MongoDB user")
+		// see version.go
+		cmd.Flags().StringVarP(&userAgentComment, "user-agent-comment", "", "", "UserAgent comment used during outbound requests")
 		cmd.Flags().Bool("debug", false, "verbose logging")
 	}
+	rootCmd.AddCommand(versionCmd)
 }

cmd/chart-repo/utils.go

@@ -166,10 +166,12 @@ func fetchRepoIndex(r repo) (*helmrepo.IndexFile, error) {
 		log.WithFields(log.Fields{"url": req.URL.String()}).WithError(err).Error("could not build repo index request")
 		return nil, err
 	}
-	req.Header.Set("User-Agent", userAgent)
+
+	req.Header.Set("User-Agent", userAgent())
 	if len(r.AuthorizationHeader) > 0 {
 		req.Header.Set("Authorization", r.AuthorizationHeader)
 	}
+
 	res, err := netClient.Do(req)
 	if res != nil {
 		defer res.Body.Close()
@@ -278,7 +280,7 @@ func fetchAndImportIcon(dbSession datastore.Session, c chart) error {
 	if err != nil {
 		return err
 	}
-	req.Header.Set("User-Agent", userAgent)
+	req.Header.Set("User-Agent", userAgent())
 	if len(c.Repo.AuthorizationHeader) > 0 {
 		req.Header.Set("Authorization", c.Repo.AuthorizationHeader)
 	}
@@ -328,7 +330,7 @@ func fetchAndImportFiles(dbSession datastore.Session, name string, r repo, cv ch
 	if err != nil {
 		return err
 	}
-	req.Header.Set("User-Agent", userAgent)
+	req.Header.Set("User-Agent", userAgent())
 	if len(r.AuthorizationHeader) > 0 {
 		req.Header.Set("Authorization", r.AuthorizationHeader)
 	}

cmd/chart-repo/utils_test.go

@@ -66,10 +66,7 @@ func (h *goodHTTPClient) Do(req *http.Request) (*http.Response, error) {
 	if req.URL.Host == "subpath.test" && req.URL.Path != "/subpath/index.yaml" {
 		w.WriteHeader(500)
 	}
-	// Ensure we're sending the right User-Agent
-	if !strings.Contains(req.Header.Get("User-Agent"), "chart-repo-sync") {
-		w.WriteHeader(500)
-	}
+
 	w.Write([]byte(validRepoIndexYAML))
 	return w.Result(), nil
 }
@@ -206,6 +203,44 @@ func Test_fetchRepoIndex(t *testing.T) {
 	})
 }
 
+func Test_fetchRepoIndexUserAgent(t *testing.T) {
+	tests := []struct {
+		name              string
+		version           string
+		userAgentComment  string
+		expectedUserAgent string
+	}{
+		{"default user agent", "", "", "chart-repo/devel"},
+		{"custom version no app", "1.0", "", "chart-repo/1.0"},
+		{"custom version and app", "1.0", "monocular/1.2", "chart-repo/1.0 (monocular/1.2)"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			// Override global variables used to generate the userAgent
+			if tt.version != "" {
+				version = tt.version
+			}
+
+			if tt.userAgentComment != "" {
+				userAgentComment = tt.userAgentComment
+			}
+
+			server := httptest.NewServer(http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
+				assert.Equal(t, tt.expectedUserAgent, req.Header.Get("User-Agent"), "expected user agent")
+				rw.Write([]byte(validRepoIndexYAML))
+			}))
+			// Close the server when test finishes
+			defer server.Close()
+
+			netClient = server.Client()
+
+			_, err := fetchRepoIndex(repo{URL: server.URL})
+			assert.NoErr(t, err)
+		})
+	}
+}
+
 func Test_parseRepoIndex(t *testing.T) {
 	tests := []struct {
 		name     string

cmd/chart-repo/version.go

@@ -16,7 +16,35 @@ limitations under the License.
 
 package main
 
-const (
-	version   = "0.3.0"
-	userAgent = "chart-repo-sync/" + version
+import (
+	"fmt"
+
+	"github.com/spf13/cobra"
+)
+
+var (
+	version          = "devel"
+	userAgentComment string
 )
+
+// Returns the user agent to be used during calls to the chart repositories
+// Examples:
+// chart-repo/devel
+// chart-repo/1.0
+// chart-repo/1.0 (monocular v1.0-beta4)
+// More info here https://github.com/kubeapps/kubeapps/issues/767#issuecomment-436835938
+func userAgent() string {
+	ua := "chart-repo/" + version
+	if userAgentComment != "" {
+		ua = fmt.Sprintf("%s (%s)", ua, userAgentComment)
+	}
+	return ua
+}
+
+var versionCmd = &cobra.Command{
+	Use:   "version",
+	Short: "returns version information",
+	Run: func(cmd *cobra.Command, args []string) {
+		fmt.Println(version)
+	},
+}