DB 적재 초기구조

internal/geo/resolver_postgres.go

@@ -0,0 +1,98 @@
+package geo
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+	"net"
+	"time"
+
+	_ "github.com/jackc/pgx/v5/stdlib"
+)
+
+const defaultLookupQuery = `
+SELECT
+  ip::text,
+  country,
+  region,
+  city,
+  latitude,
+  longitude
+FROM geoip.lookup_city($1);
+`
+
+type postgresResolver struct {
+	db          *sql.DB
+	lookupQuery string
+}
+
+func newPostgresResolver(databaseURL, lookupQuery string) (Resolver, error) {
+	if databaseURL == "" {
+		return nil, errors.New("database url is required for postgres backend")
+	}
+
+	db, err := sql.Open("pgx", databaseURL)
+	if err != nil {
+		return nil, err
+	}
+
+	db.SetMaxOpenConns(10)
+	db.SetMaxIdleConns(2)
+	db.SetConnMaxIdleTime(5 * time.Minute)
+
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+	if err := db.PingContext(ctx); err != nil {
+		_ = db.Close()
+		return nil, err
+	}
+
+	if lookupQuery == "" {
+		lookupQuery = defaultLookupQuery
+	}
+
+	return &postgresResolver{
+		db:          db,
+		lookupQuery: lookupQuery,
+	}, nil
+}
+
+func (r *postgresResolver) Close() error {
+	return r.db.Close()
+}
+
+func (r *postgresResolver) Lookup(ipStr string) (Location, error) {
+	ip := net.ParseIP(ipStr)
+	if ip == nil {
+		return Location{}, ErrInvalidIP
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
+	defer cancel()
+
+	row := r.db.QueryRowContext(ctx, r.lookupQuery, ip.String())
+
+	var (
+		resolvedIP          string
+		country, region     sql.NullString
+		city                sql.NullString
+		latitude, longitude sql.NullFloat64
+	)
+
+	if err := row.Scan(&resolvedIP, &country, &region, &city, &latitude, &longitude); err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return Location{}, ErrNotFound
+		}
+		return Location{}, err
+	}
+
+	return Location{
+		IP:        resolvedIP,
+		Country:   country.String,
+		Region:    region.String,
+		City:      city.String,
+		Address:   buildAddress(city.String, region.String, country.String),
+		Latitude:  latitude.Float64,
+		Longitude: longitude.Float64,
+	}, nil
+}