refactor: move geoip setup into geoip.OpenDatabases, remove cmd/check-ip/geo.go

OpenDatabases(confPath, cityPath, asnPath) handles conf discovery, cache
dir setup, and Databases construction. DefaultConfPaths lists the standard
GeoIP.conf locations. cmd/check-ip/geo.go deleted; main calls one function.

cmd/check-ip/geo.go

@@ -1,65 +0,0 @@
-package main
-
-import (
-	"fmt"
-	"os"
-	"path/filepath"
-
-	"github.com/therootcompany/golib/net/geoip"
-)
-
-// discoverConf looks for GeoIP.conf in the current directory and then
-// at ~/.config/maxmind/GeoIP.conf. Returns the path or "".
-func discoverConf() string {
-	if _, err := os.Stat("GeoIP.conf"); err == nil {
-		return "GeoIP.conf"
-	}
-	if home, err := os.UserHomeDir(); err == nil {
-		p := filepath.Join(home, ".config", "maxmind", "GeoIP.conf")
-		if _, err := os.Stat(p); err == nil {
-			return p
-		}
-	}
-	return ""
-}
-
-// setupGeo returns a Databases ready to Init, or nil if geoip is not configured.
-//
-//   - confPath="" → auto-discover GeoIP.conf from cwd and ~/.config/maxmind/
-//   - conf found   → auto-download; cityPath/asnPath override the default locations
-//   - conf absent  → cityPath and asnPath must point to existing .mmdb files
-//   - no conf and no paths → geoip disabled (returns nil)
-func setupGeo(confPath, cityPath, asnPath string) (*geoip.Databases, error) {
-	if confPath == "" {
-		confPath = discoverConf()
-	}
-
-	if confPath != "" {
-		cfg, err := geoip.ParseConf(confPath)
-		if err != nil {
-			return nil, fmt.Errorf("geoip-conf: %w", err)
-		}
-		dbDir := cfg.DatabaseDirectory
-		if dbDir == "" {
-			if dbDir, err = geoip.DefaultCacheDir(); err != nil {
-				return nil, fmt.Errorf("geoip cache dir: %w", err)
-			}
-		}
-		if err := os.MkdirAll(dbDir, 0o755); err != nil {
-			return nil, fmt.Errorf("mkdir %s: %w", dbDir, err)
-		}
-		if cityPath == "" {
-			cityPath = filepath.Join(dbDir, geoip.CityEdition+".mmdb")
-		}
-		if asnPath == "" {
-			asnPath = filepath.Join(dbDir, geoip.ASNEdition+".mmdb")
-		}
-		return geoip.New(cfg.AccountID, cfg.LicenseKey).NewDatabases(cityPath, asnPath), nil
-	}
-
-	if cityPath == "" && asnPath == "" {
-		return nil, nil
-	}
-	// Explicit paths only — no auto-download. Init will fail if files are absent.
-	return geoip.NewDatabases(cityPath, asnPath), nil
-}

cmd/check-ip/main.go

@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"github.com/therootcompany/golib/net/dataset"
+	"github.com/therootcompany/golib/net/geoip"
 	"github.com/therootcompany/golib/net/gitshallow"
 	"github.com/therootcompany/golib/net/httpcache"
 	"github.com/therootcompany/golib/net/ipcohort"
@@ -97,7 +98,7 @@ func main() {
 
 	// -- GeoIP (optional) --------------------------------------------------
 
-	geo, err := setupGeo(*geoipConf, *cityDB, *asnDB)
+	geo, err := geoip.OpenDatabases(*geoipConf, *cityDB, *asnDB)
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "error: %v\n", err)
 		os.Exit(1)

net/geoip/geoip.go

@@ -34,6 +34,62 @@ type Downloader struct {
 	Timeout    time.Duration // 0 uses 5m
 }
 
+// DefaultConfPaths returns the standard locations where GeoIP.conf is looked
+// up: ./GeoIP.conf, then ~/.config/maxmind/GeoIP.conf.
+func DefaultConfPaths() []string {
+	paths := []string{"GeoIP.conf"}
+	if home, err := os.UserHomeDir(); err == nil {
+		paths = append(paths, filepath.Join(home, ".config", "maxmind", "GeoIP.conf"))
+	}
+	return paths
+}
+
+// OpenDatabases discovers credentials and paths, then returns a ready-to-Init
+// Databases. Returns nil with no error when geoip is not configured.
+//
+//   - confPath=""  → auto-discover from DefaultConfPaths
+//   - conf found   → auto-download; cityPath/asnPath override default locations
+//   - no conf      → cityPath and asnPath must point to existing .mmdb files
+//   - no conf and no paths → geoip disabled (returns nil, nil)
+func OpenDatabases(confPath, cityPath, asnPath string) (*Databases, error) {
+	if confPath == "" {
+		for _, p := range DefaultConfPaths() {
+			if _, err := os.Stat(p); err == nil {
+				confPath = p
+				break
+			}
+		}
+	}
+
+	if confPath != "" {
+		cfg, err := ParseConf(confPath)
+		if err != nil {
+			return nil, fmt.Errorf("geoip-conf: %w", err)
+		}
+		dbDir := cfg.DatabaseDirectory
+		if dbDir == "" {
+			if dbDir, err = DefaultCacheDir(); err != nil {
+				return nil, fmt.Errorf("geoip cache dir: %w", err)
+			}
+		}
+		if err := os.MkdirAll(dbDir, 0o755); err != nil {
+			return nil, fmt.Errorf("mkdir %s: %w", dbDir, err)
+		}
+		if cityPath == "" {
+			cityPath = filepath.Join(dbDir, CityEdition+".mmdb")
+		}
+		if asnPath == "" {
+			asnPath = filepath.Join(dbDir, ASNEdition+".mmdb")
+		}
+		return New(cfg.AccountID, cfg.LicenseKey).NewDatabases(cityPath, asnPath), nil
+	}
+
+	if cityPath == "" && asnPath == "" {
+		return nil, nil
+	}
+	return NewDatabases(cityPath, asnPath), nil
+}
+
 // DefaultCacheDir returns the OS cache directory for MaxMind databases,
 // e.g. ~/.cache/maxmind on Linux or ~/Library/Caches/maxmind on macOS.
 func DefaultCacheDir() (string, error) {