Full MVC of gitlab-zoekt-indexer

cmd/gitlab-zoekt-indexer/main.go

@@ -6,7 +6,6 @@ import (
 	"errors"
 	"flag"
 	"fmt"
-	"io"
 	"log"
 	"net/http"
 	"os"
@@ -19,6 +18,7 @@ import (
 	"github.com/prometheus/client_golang/prometheus/collectors"
 	"github.com/prometheus/client_golang/prometheus/promauto"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
+	// "gitlab.com/gitlab-org/labkit/correlation"
 	"gitlab.com/gitlab-org/search-team/gitlab-zoekt-indexer/indexer"
 )
 
@@ -57,6 +57,11 @@ func (s *indexServer) createIndexDir() {
 func (s *indexServer) handleStatus() http.HandlerFunc {
 	route := "status"
 
+	type response struct {
+		Success bool
+		SHA     string
+	}
+
 	return func(w http.ResponseWriter, r *http.Request) {
 		param := chi.URLParam(r, "id")
 		repoID, err := strconv.ParseUint(param, 10, 32)
@@ -83,12 +88,12 @@ func (s *indexServer) handleStatus() http.HandlerFunc {
 			return
 		}
 
-		response := map[string]any{
-			"Success": true,
-			"SHA":     currentSHA,
+		resp := response{
+			Success: true,
+			SHA:     currentSHA,
 		}
 
-		s.respondWith(w, r, route, response)
+		s.respondWith(w, r, route, resp)
 	}
 }
 
@@ -98,14 +103,22 @@ func (s *indexServer) handleMetrics() http.HandlerFunc {
 	}
 }
 
+func (s *indexServer) decode(r *http.Request, v interface{}) error {
+	dec := json.NewDecoder(r.Body)
+	dec.DisallowUnknownFields()
+	return dec.Decode(v)
+}
+
 func (s *indexServer) handleIndex() http.HandlerFunc {
 	route := "index"
 
-	parseRequest := func(r io.Reader) (indexRequest, error) {
-		dec := json.NewDecoder(r)
-		dec.DisallowUnknownFields()
+	type response struct {
+		Success bool
+	}
+
+	parseRequest := func(r *http.Request) (indexRequest, error) {
 		var req indexRequest
-		err := dec.Decode(&req)
+		err := s.decode(r, &req)
 
 		if err != nil {
 			return req, errors.New("json parser error")
@@ -123,7 +136,7 @@ func (s *indexServer) handleIndex() http.HandlerFunc {
 	}
 
 	return func(w http.ResponseWriter, r *http.Request) {
-		req, err := parseRequest(r.Body)
+		req, err := parseRequest(r)
 		if err != nil {
 			http.Error(w, err.Error(), http.StatusBadRequest)
 			return
@@ -135,11 +148,11 @@ func (s *indexServer) handleIndex() http.HandlerFunc {
 			return
 		}
 
-		response := map[string]any{
-			"Success": true,
+		resp := response{
+			Success: true,
 		}
 
-		s.respondWith(w, r, route, response)
+		s.respondWith(w, r, route, resp)
 	}
 }
 
@@ -171,6 +184,29 @@ func (s *indexServer) indexRepository(req indexRequest) error {
 
 func (s *indexServer) handleTruncate() http.HandlerFunc {
 	route := "truncate"
+
+	type response struct {
+		Success bool
+	}
+
+	emptyDirectory := func(dir string) error {
+		files, err := os.ReadDir(dir)
+
+		if err != nil {
+			return err
+		}
+
+		for _, file := range files {
+			filePath := filepath.Join(dir, file.Name())
+			err := os.RemoveAll(filePath)
+			if err != nil {
+				return err
+			}
+		}
+
+		return nil
+	}
+
 	return func(w http.ResponseWriter, r *http.Request) {
 		err := emptyDirectory(s.indexDir)
 
@@ -181,11 +217,11 @@ func (s *indexServer) handleTruncate() http.HandlerFunc {
 			return
 		}
 
-		response := map[string]any{
-			"Success": true,
+		resp := response{
+			Success: true,
 		}
 
-		s.respondWith(w, r, route, response)
+		s.respondWith(w, r, route, resp)
 	}
 }
 
@@ -194,24 +230,31 @@ func (s *indexServer) respondWith(w http.ResponseWriter, r *http.Request, route
 
 	if err := json.NewEncoder(w).Encode(data); err != nil {
 		s.respondWithError(w, r, route, err)
+		return
 	}
 
 	s.incrementRequestsTotal(r.Method, route, http.StatusOK)
 }
 
 func (s *indexServer) respondWithError(w http.ResponseWriter, r *http.Request, route string, err error) {
-	responseCode := http.StatusInternalServerError
+	type response struct {
+		Success bool
+		Error   string
+	}
 
-	s.incrementRequestsTotal(r.Method, route, responseCode)
+	responseCode := http.StatusInternalServerError
 
 	w.Header().Set("Content-Type", "application/json")
 	w.WriteHeader(responseCode)
-	response := map[string]any{
-		"Success": false,
-		"Error":   err.Error(),
+
+	resp := response{
+		Success: false,
+		Error:   err.Error(),
 	}
 
-	_ = json.NewEncoder(w).Encode(response)
+	_ = json.NewEncoder(w).Encode(resp)
+
+	s.incrementRequestsTotal(r.Method, route, responseCode)
 }
 
 func (s *indexServer) incrementRequestsTotal(method, route string, responseCode int) {
@@ -236,24 +279,6 @@ func (s *indexServer) initMetrics() {
 	)
 }
 
-func emptyDirectory(dir string) error {
-	files, err := os.ReadDir(dir)
-
-	if err != nil {
-		return err
-	}
-
-	for _, file := range files {
-		filePath := filepath.Join(dir, file.Name())
-		err := os.RemoveAll(filePath)
-		if err != nil {
-			return err
-		}
-	}
-
-	return nil
-}
-
 func parseOptions() options {
 	indexDir := flag.String("index_dir", "", "directory holding index shards.")
 	listen := flag.String("listen", ":6060", "listen on this address.")
@@ -282,11 +307,15 @@ func main() {
 func (s *indexServer) startIndexingApi(listen string) {
 	s.initMetrics()
 	s.createIndexDir()
-	router := s.router()
+
+	httpServer := http.Server{
+		Addr:    listen,
+		Handler: s.router(),
+	}
 
 	log.Printf("Starting server on %s", listen)
 
-	if err := http.ListenAndServe(listen, router); err != nil {
+	if err := httpServer.ListenAndServe(); err != nil {
 		log.Fatal(err)
 	}
 }