refactor(storage): new storage file structure

- new directory structure containing manifest.json and one json file per provider, by default.
- the manifest.json file can specify a filepath for each vpn provider
- each vpn provider json data file can contain the `"preferred": true` field to enforce it is used even if outdated, unless there is a version mismatch
- `STORAGE_SERVERS_DIRECTORY_PATH` replaces `STORAGE_FILEPATH` (which is now a migration source only). It sets the directory where server manifest and per-provider JSON files are stored (default: `/gluetun/servers/`).
- First-run migration: On startup, gluetun checks for the old /gluetun/servers.json file; if found and no new manifest exists, it automatically migrates all data to /gluetun/servers/ directory structure
- Silent fallback: If legacy file isn't found, uses the new directory path normally
- Legacy cleanup: After successful migration, attempts to remove the old fat JSON file (logs warning only if removal fails, e.g., read-only bind mounts)

gluetun-servers/cmd/updater/main.go

@@ -0,0 +1,43 @@
+package main
+
+import (
+	"context"
+	"flag"
+	"net/http"
+	"os"
+	"path/filepath"
+	"time"
+
+	"github.com/qdm12/gluetun-servers/pkg/updaters"
+	"github.com/qdm12/log"
+)
+
+func main() {
+	defaultOutputDir := filepath.Join("pkg", "servers")
+	outputDir := flag.String("output-dir", defaultOutputDir,
+		"directory to write per-provider JSON files to")
+	protonEmail := flag.String("proton-email", os.Getenv("GLUETUN_PROTON_EMAIL"),
+		"ProtonVPN account email")
+	protonPassword := flag.String("proton-password", os.Getenv("GLUETUN_PROTON_PASSWORD"),
+		"ProtonVPN account password")
+	ipinfoToken := flag.String("ipinfo-token", os.Getenv("IPINFO_TOKEN"),
+		"IPInfo token used for public IP lookups")
+	flag.Parse()
+
+	client := &http.Client{Timeout: time.Minute}
+	settings := updaters.UpdateAllSettings{
+		OutputPath:     outputDir,
+		ProtonEmail:    protonEmail,
+		ProtonPassword: protonPassword,
+		IpinfoToken:    ipinfoToken,
+	}
+
+	logger := log.New()
+	err := updaters.UpdateAll(context.Background(), client, logger, settings)
+	if err != nil {
+		logger.Errorf("update failed: %v", err)
+		os.Exit(1)
+	}
+
+	logger.Infof("update completed successfully, data files written to %s", *outputDir)
+}