lib/geoip, cmd/relaypoolsrv, cmd/ursrv: Automatically manage GeoIP updates (#9342)

This adds a small package `geoip` which knows how to download and manage
the Maxmind GeoLite2 database we use. This removes the need for various
scripts to download and manage the geoip database, something that today
happens on Docker startup for the relay pool server and using various
hand written hacks for the usage reporting server.

The database is downloaded when needed and then refreshed on a
best-effort basis weekly.

cmd/ursrv/serve/serve.go

@@ -8,6 +8,7 @@ package serve
 
 import (
 	"bytes"
+	"context"
 	"database/sql"
 	"embed"
 	"encoding/json"
@@ -17,6 +18,7 @@ import (
 	"log"
 	"net"
 	"net/http"
+	"os"
 	"regexp"
 	"sort"
 	"strconv"
@@ -26,20 +28,21 @@ import (
 	"unicode"
 
 	_ "github.com/lib/pq" // PostgreSQL driver
-	"github.com/oschwald/geoip2-golang"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"golang.org/x/text/cases"
 	"golang.org/x/text/language"
 
+	"github.com/syncthing/syncthing/lib/geoip"
 	"github.com/syncthing/syncthing/lib/upgrade"
 	"github.com/syncthing/syncthing/lib/ur/contract"
 )
 
 type CLI struct {
-	Debug     bool   `env:"UR_DEBUG"`
-	DBConn    string `env:"UR_DB_URL" default:"postgres://user:password@localhost/ur?sslmode=disable"`
-	Listen    string `env:"UR_LISTEN" default:"0.0.0.0:8080"`
-	GeoIPPath string `env:"UR_GEOIP" default:"GeoLite2-City.mmdb"`
+	Debug           bool   `env:"UR_DEBUG"`
+	DBConn          string `env:"UR_DB_URL" default:"postgres://user:password@localhost/ur?sslmode=disable"`
+	Listen          string `env:"UR_LISTEN" default:"0.0.0.0:8080"`
+	GeoIPLicenseKey string `env:"UR_GEOIP_LICENSE_KEY"`
+	GeoIPAccountID  int    `env:"UR_GEOIP_ACCOUNT_ID"`
 }
 
 //go:embed static
@@ -189,10 +192,16 @@ func (cli *CLI) Run() error {
 		log.Fatalln("listen:", err)
 	}
 
+	geoip, err := geoip.NewGeoLite2CityProvider(context.Background(), cli.GeoIPAccountID, cli.GeoIPLicenseKey, os.TempDir())
+	if err != nil {
+		log.Fatalln("geoip:", err)
+	}
+	go geoip.Serve(context.TODO())
+
 	srv := &server{
-		db:        db,
-		debug:     cli.Debug,
-		geoIPPath: cli.GeoIPPath,
+		db:    db,
+		debug: cli.Debug,
+		geoip: geoip,
 	}
 	http.HandleFunc("/", srv.rootHandler)
 	http.HandleFunc("/newdata", srv.newDataHandler)
@@ -213,9 +222,9 @@ func (cli *CLI) Run() error {
 }
 
 type server struct {
-	debug     bool
-	db        *sql.DB
-	geoIPPath string
+	debug bool
+	db    *sql.DB
+	geoip *geoip.Provider
 
 	cacheMut        sync.Mutex
 	cachedIndex     []byte
@@ -238,7 +247,7 @@ func (s *server) cacheRefresher() {
 }
 
 func (s *server) refreshCacheLocked() error {
-	rep := getReport(s.db, s.geoIPPath)
+	rep := getReport(s.db, s.geoip)
 	buf := new(bytes.Buffer)
 	err := tpl.Execute(buf, rep)
 	if err != nil {
@@ -492,15 +501,7 @@ type weightedLocation struct {
 	Weight int `json:"weight"`
 }
 
-func getReport(db *sql.DB, geoIPPath string) map[string]interface{} {
-	geoip, err := geoip2.Open(geoIPPath)
-	if err != nil {
-		log.Println("opening geoip db", err)
-		geoip = nil
-	} else {
-		defer geoip.Close()
-	}
-
+func getReport(db *sql.DB, geoip *geoip.Provider) map[string]interface{} {
 	nodes := 0
 	countriesTotal := 0
 	var versions []string