Move hacks to hack (match k8s pattern).

hack/crawl/backend/search_backend.go

@@ -0,0 +1,195 @@
+package server
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"log"
+	"net/http"
+	"os"
+	"strconv"
+	"strings"
+
+	"github.com/gorilla/mux"
+	"github.com/rs/cors"
+
+	"sigs.k8s.io/kustomize/hack/crawl/index"
+)
+
+type kustomizeSearch struct {
+	ctx context.Context
+	// Eventually pIndex *index.PlugginIndex
+	idx    *index.KustomizeIndex
+	router *mux.Router
+	log    *log.Logger
+}
+
+// New server. Creating a server does not launch it. To launch simply:
+//	srv, _ := NewKustomizeSearch(context.Backgroud())
+//	err := srv.Serve()
+//	if err != nil {
+//		// Handle server issues.
+//	}
+//
+// The server has three enpoints, two of which are functional:
+//
+// /search: processes the ?q= parameter for a text query and
+// returns a list of 10 resutls starting from the ?from= value provided,
+// with the default being zero.
+//
+// /metrics: returns overall metrics about the files indexed. Returns
+// timeseries data for kustomization files, and returns breakdown of file
+// counts by their 'kind' fields
+//
+// /register: not implemented, but meant as an endpoint for adding new
+// kustomization files to the corpus.
+func NewKustomizeSearch(ctx context.Context) (*kustomizeSearch, error) {
+	idx, err := index.NewKustomizeIndex(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	ks := &kustomizeSearch{
+		ctx:    ctx,
+		idx:    idx,
+		router: mux.NewRouter(),
+		log: log.New(os.Stdout, "Kustomize server: ",
+			log.LstdFlags|log.Llongfile|log.LUTC),
+	}
+
+	return ks, nil
+}
+
+// Set up common middleware and the routes for the server.
+func (ks *kustomizeSearch) routes() {
+
+	// Setup middleware.
+	ks.router.Use(func(handler http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			w.Header().Set("Content-Type", "application/json")
+			handler.ServeHTTP(w, r)
+		})
+	})
+
+	ks.router.HandleFunc("/liveness", ks.liveness()).Methods(http.MethodGet)
+	ks.router.HandleFunc("/readiness", ks.readiness()).Methods(http.MethodGet)
+	ks.router.HandleFunc("/search", ks.search()).Methods(http.MethodGet)
+	ks.router.HandleFunc("/metrics", ks.metrics()).Methods(http.MethodGet)
+	ks.router.HandleFunc("/register", ks.register()).Methods(http.MethodPost)
+}
+
+// Start listening and serving on the provided port.
+func (ks *kustomizeSearch) Serve(port int) error {
+	ks.routes()
+	handler := cors.Default().Handler(ks.router)
+	s := &http.Server{
+		Addr:    fmt.Sprintf(":%d", port),
+		Handler: handler,
+		// Timeouts/Limits
+	}
+
+	return s.ListenAndServe()
+}
+
+// /liveness endpoint
+func (ks *kustomizeSearch) liveness() http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusOK)
+	}
+}
+
+// /readyness endpoint
+func (ks *kustomizeSearch) readiness() http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		opt := index.KustomizeSearchOptions{}
+		_, err := ks.idx.Search("", opt)
+		if err != nil {
+			http.Error(w,
+				`{ "error": "could not connect to database" }`,
+				http.StatusInternalServerError)
+			return
+		}
+		w.WriteHeader(http.StatusOK)
+	}
+}
+
+// /register endpoint.
+func (ks *kustomizeSearch) register() http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		http.Error(w, "not implemented", http.StatusInternalServerError)
+	}
+}
+
+// /search endpoint.
+func (ks *kustomizeSearch) search() http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		values := r.URL.Query()
+
+		queries := values["q"]
+		ks.log.Println("Query: ", values)
+
+		var from int
+		fromParam := values["from"]
+		if len(fromParam) > 0 {
+			from, _ = strconv.Atoi(fromParam[0])
+			if from < 0 {
+				from = 0
+			}
+		}
+		_, noKinds := values["nokinds"]
+
+		opt := index.KustomizeSearchOptions{
+			SearchOptions: index.SearchOptions{
+				Size: 10,
+				From: from,
+			},
+			KindAggregation: !noKinds,
+		}
+
+		results, err := ks.idx.Search(strings.Join(queries, " "), opt)
+		if err != nil {
+			ks.log.Println("Error: ", err)
+			http.Error(w, fmt.Sprintf(
+				`{ "error": "could not complete the query" }`),
+				http.StatusInternalServerError)
+			return
+		}
+
+		enc := json.NewEncoder(w)
+		setIndent(enc)
+		if err = enc.Encode(results); err != nil {
+			http.Error(w, `{ "error": "failed to send back results" }`,
+				http.StatusInternalServerError)
+			return
+		}
+		return
+	}
+}
+
+// metrics endpoint.
+func (ks *kustomizeSearch) metrics() http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		res, err := ks.idx.Search("", index.KustomizeSearchOptions{
+			KindAggregation:       true,
+			TimeseriesAggregation: true,
+		})
+		if err != nil {
+			http.Error(w, `{ "error": "could not perform the search."}`,
+				http.StatusInternalServerError)
+			return
+		}
+
+		enc := json.NewEncoder(w)
+		setIndent(enc)
+		if err := enc.Encode(res); err != nil {
+			http.Error(w, `{ "error": "could not format return value" }`,
+				http.StatusInternalServerError)
+			return
+		}
+	}
+}
+
+// make json response human readable.
+func setIndent(e *json.Encoder) {
+	e.SetIndent("", "  ")
+}