f-25: code: add db api

Signed-off-by: GnomeZworc <nicolas.boufidjeline@g3e.fr>

cmd/agent/main.go

@@ -51,6 +51,10 @@ func main() {
 	d := dispatcher.New(q, db, cfg, log.With(slog.String("component", "dispatcher")))
 	go agentapi.New(d, db, log.With(slog.String("component", "api"))).Start(apiAddr)
 	go promserver.Start(promAddr, registry)
+	if cfg.Admin.Enabled {
+		adminAddr := fmt.Sprintf("%s:%d", cfg.Admin.Address, cfg.Admin.Port)
+		go kv.NewAdminServer(db, log.With(slog.String("component", "admin"))).Start(adminAddr)
+	}
 
 	select {}
 }

conf/agent/config.exemple.yml

@@ -39,6 +39,12 @@ interfaces:
 metadata:
   run_dir: "/run/two/metadata"
 
+# Admin API (read-only DB inspection, loopback only)
+admin:
+  enabled: false
+  address: "127.0.0.1"
+  port: 9091
+
 # Logging configuration
 logger:
   # Log level: debug, info, warn, error (default: info)

internal/config/agent/struct.go

@@ -31,6 +31,11 @@ type Config struct {
 	Metadata struct {
 		RunDir string `mapstructure:"run_dir"`
 	} `mapstructure:"metadata"`
+	Admin struct {
+		Enabled bool   `mapstructure:"enabled"`
+		Address string `mapstructure:"address"`
+		Port    int    `mapstructure:"port"`
+	} `mapstructure:"admin"`
 	DefaultInterface string            `mapstructure:"default_interface"`
 	Interfaces       map[string]string `mapstructure:"interfaces"`
 }
@@ -50,6 +55,9 @@ func LoadConfig(path string) (*Config, error) {
 	v.SetDefault("dispatcher.timeout_seconds", 300)
 	v.SetDefault("dispatcher.poll_seconds", 2)
 	v.SetDefault("metadata.run_dir", "/run/two/metadata")
+	v.SetDefault("admin.enabled", false)
+	v.SetDefault("admin.address", "127.0.0.1")
+	v.SetDefault("admin.port", 9091)
 	v.SetDefault("default_interface", "br-000000")
 	v.SetDefault("logger.level", "info")
 	v.SetDefault("logger.debug", false)

pkg/db/kv/admin_server.go

@@ -0,0 +1,52 @@
+package kv
+
+import (
+	"fmt"
+	"log/slog"
+	"net/http"
+	"sort"
+
+	"github.com/dgraph-io/badger/v4"
+)
+
+type AdminServer struct {
+	db     *badger.DB
+	logger *slog.Logger
+}
+
+func NewAdminServer(db *badger.DB, logger *slog.Logger) *AdminServer {
+	return &AdminServer{db: db, logger: logger}
+}
+
+func (s *AdminServer) Start(address string) {
+	mux := http.NewServeMux()
+	mux.HandleFunc("/db", s.dbHandler)
+	s.logger.Info("admin server listening", "address", address)
+	if err := http.ListenAndServe(address, mux); err != nil {
+		s.logger.Error("admin server stopped", "error", err)
+	}
+}
+
+func (s *AdminServer) dbHandler(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodGet {
+		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+		return
+	}
+
+	entries, err := ListByPrefix(s.db, r.URL.Query().Get("prefix"))
+	if err != nil {
+		http.Error(w, "db error: "+err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	keys := make([]string, 0, len(entries))
+	for k := range entries {
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+
+	w.Header().Set("Content-Type", "text/plain; charset=utf-8")
+	for _, k := range keys {
+		fmt.Fprintf(w, "%s=%s\n", k, entries[k])
+	}
+}

pkg/db/kv/init.go

@@ -17,7 +17,8 @@ func InitDB(conf Config, readonly bool) *badger.DB {
 	opts.NumLevelZeroTablesStall = 2
 	db, err := badger.Open(opts)
 	if err != nil {
-		log.Fatalf("kv.InitDB (readonly=%v, path=%s): %v", readonly, conf.Path, err)
+		log.Printf("kv.InitDB (readonly=%v, path=%s): %v", readonly, conf.Path, err)
+		panic(err)
 	}
 	return db
 }