Maltrail's trails.csv as an API service

maltrail-feeds-api-service.go

package main

import (
	"encoding/csv"
	"encoding/json"
	"flag"
	"fmt"
	"io"
	"log"
	"net/http"
	"os"
	"time"

	"github.com/gorilla/mux"
)

type Verdict struct {
	Reason string `json:"reason"`
	Source string `json:"source"`
}

type Entry struct {
	Value string `json:"entry"`
	Verdict
}

type DB struct {
	Entries *[]Entry `json:"entries,omitempty"`
}

type Output struct {
	Count   int       `json:"hits"`
	Date    time.Time `json:"timestamp"`
	Entries []Entry   `json:"entries"`
}

func main() {
	var badEntries []Entry
	host := flag.String("h", "127.0.0.1", "Host address to bind")
	port := flag.Int("p", 9000, "Port to bind")
	trails := flag.String("t", "trails.csv", "MalTrails CSV file")
	flag.Parse()

	db := &DB{&badEntries}
	go db.fillDBFromTrails(*trails)

	m := mux.NewRouter()
	m.HandleFunc("/search/{item}", db.handleSearch).Methods("GET")

	log.Println("Starting server...")
	srv := &http.Server{
		Handler:      m,
		Addr:         fmt.Sprintf("%s:%d", *host, *port),
		WriteTimeout: 15 * time.Second,
		ReadTimeout:  15 * time.Second,
	}

	log.Fatal(srv.ListenAndServe())
}

func (db *DB) fillDBFromTrails(name string) {
	log.Println("Start filling database")
	f, err := os.Open(name)
	if err != nil {
		log.Println("error opening file ", err)
		os.Exit(1)
	}
	defer f.Close()

	r := csv.NewReader(f)
	for {
		record, err := r.Read()
		if err == io.EOF {
			break
		}
		if err != nil {
			log.Fatal(err)
		}

		*db.Entries = append(*db.Entries, Entry{record[0], Verdict{record[1], record[2]}})
	}
	log.Println("Ended filling a database")
}

func (db *DB) handleSearch(w http.ResponseWriter, r *http.Request) {
	vars := mux.Vars(r)
	f := searchEntry(vars["item"], db.Entries)
	o := &Output{
		Count:   len(f),
		Date:    time.Now().UTC(),
		Entries: f,
	}

	oj, err := json.Marshal(o)
	if err != nil {
		log.Println(err)
	}

	if o.Count == 0 {
		w.WriteHeader(404)
	}

	w.Write(oj)
}

func searchEntry(s string, db *[]Entry) []Entry {
	var found []Entry
	for _, f := range *db {
		if f.Value == s {
			found = append(found, f)
		}
	}
	return found
}