Basic API to fetch data from maxmind geoip databases over http

2018-07-12 23:54:37 -07:00
parent dc4018e8f4
commit f5f0ea4931
253 changed files with 167757 additions and 0 deletions
--- a/geoipapi.go
+++ b/geoipapi.go
@@ -0,0 +1,176 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"log"
+	"net"
+	"net/http"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/oschwald/geoip2-golang"
+)
+
+type geoType uint8
+
+const (
+	countryDB geoType = iota
+	cityDB
+	asnDB
+)
+
+var dbFiles map[geoType][]string
+
+func init() {
+	dbFiles = map[geoType][]string{
+		countryDB: []string{"GeoIP2-Country.mmdb", "GeoLite2-Country.mmdb"},
+		asnDB:     []string{"GeoIP2-ISP.mmdb"},
+		cityDB:    []string{"GeoIP2-City.mmdb", "GeoLite2-City.mmdb"},
+	}
+}
+
+func main() {
+
+	rdr, err := open(cityDB)
+	if err != nil {
+		log.Fatalf("opening db: %s", err)
+	}
+
+	if len(os.Args) > 1 {
+		for _, str := range os.Args[1:] {
+			log.Printf("%q", str)
+			ip := net.ParseIP(str)
+			city, err := rdr.City(ip)
+			if err != nil {
+				log.Printf("error looking up %q: %s", ip, err)
+				continue
+			}
+			fmt.Printf("%s: %s\n", ip, city.Country.IsoCode)
+		}
+		os.Exit(0)
+	}
+
+	err = setupHTTP(rdr)
+	if err != nil {
+		log.Fatalf("http: %s", err)
+	}
+}
+
+func setupHTTP(rdr *geoip2.Reader) error {
+	mux := http.NewServeMux()
+	mux.HandleFunc("/api/country", handleCountry)
+	mux.HandleFunc("/api/json", handleJSON)
+	mux.HandleFunc("/healthz", handleHealth)
+	return http.ListenAndServe(":8009", mux)
+}
+
+func getCityIP(ip net.IP) (*geoip2.City, error) {
+	rdr, err := open(cityDB)
+	if err != nil {
+		return nil, err
+	}
+	city, err := rdr.City(ip)
+	if err != nil {
+		log.Printf("error looking up %q: %s", ip, err)
+		return nil, fmt.Errorf("db lookup error")
+	}
+	return city, nil
+}
+
+func getCity(req *http.Request) (*geoip2.City, error) {
+	req.ParseForm()
+	ipStr := req.FormValue("ip")
+	ip := net.ParseIP(ipStr)
+	if ip == nil {
+		return nil, fmt.Errorf("Missing IP")
+	}
+	return getCityIP(ip)
+}
+
+func handleJSON(w http.ResponseWriter, req *http.Request) {
+	city, err := getCity(req)
+	if err != nil {
+		log.Printf("getCity error: %s", err)
+		http.Error(w, "data error", 500)
+		return
+	}
+
+	b, err := json.Marshal(&city)
+	if err != nil {
+		log.Printf("Error marshaling JSON: %s", err)
+		http.Error(w, "internal error", 500)
+		return
+	}
+	w.WriteHeader(200)
+	w.Write(b)
+}
+
+func handleCountry(w http.ResponseWriter, req *http.Request) {
+	city, err := getCity(req)
+	if err != nil {
+		log.Printf("getCity error: %s", err)
+		http.Error(w, "data error", 500)
+		return
+	}
+
+	w.WriteHeader(200)
+	w.Write([]byte(strings.ToLower(city.Country.IsoCode)))
+}
+
+func handleHealth(w http.ResponseWriter, req *http.Request) {
+	ip := net.ParseIP("199.43.0.43")
+	city, err := getCityIP(ip)
+	if err != nil {
+		log.Printf("getCity error: %s", err)
+		http.Error(w, "data error", 500)
+		return
+	}
+
+	w.WriteHeader(200)
+	w.Write([]byte(strings.ToLower(city.Country.IsoCode)))
+}
+
+func open(t geoType) (*geoip2.Reader, error) {
+
+	dir := findDB()
+
+	fileName := ""
+
+	found := false
+	for _, f := range dbFiles[t] {
+		fileName = filepath.Join(dir, f)
+		if _, err := os.Stat(fileName); err == nil {
+			found = true
+			break
+		}
+	}
+	if !found {
+		return nil, fmt.Errorf("could not find '%s' in '%s'", dbFiles[t], dir)
+	}
+
+	rdr, err := geoip2.Open(fileName)
+
+	return rdr, err
+
+}
+
+func findDB() string {
+	dirs := []string{
+		"/usr/share/GeoIP/",       // Linux default
+		"/usr/share/local/GeoIP/", // source install?
+		"/usr/local/share/GeoIP/", // FreeBSD
+		"/opt/local/share/GeoIP/", // MacPorts
+	}
+	for _, dir := range dirs {
+		if _, err := os.Stat(dir); err != nil {
+			if os.IsExist(err) {
+				log.Println(err)
+			}
+			continue
+		}
+		return dir
+	}
+	return ""
+}