feat(agent) multi-driver db monitoring, hot-plug config, release pipeline

cmd/agent/main.go

@@ -2,24 +2,144 @@ package main
 
 import (
 	"context"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"log"
 	"os"
 	"os/signal"
 	"syscall"
 
 	"bugs.watch/agent/internal/agent"
+	"bugs.watch/agent/internal/config"
+	"bugs.watch/agent/internal/dbmanager"
 )
 
 func main() {
+	// Peek at the first arg before flag parsing to detect sub-commands.
+	if len(os.Args) > 1 && os.Args[1] == "db" {
+		runDBCmd(os.Args[2:])
+		return
+	}
+
+	cfg, err := config.Load()
+	if err != nil {
+		log.Fatalf("configuration error: %v", err)
+	}
+
+	flag.StringVar(&cfg.DBConfigPath, "db-config", cfg.DBConfigPath,
+		"path to databases.json (default /etc/bugswatch/databases.json, or $BUGSWATCH_DB_CONFIG)")
+	flag.Parse()
+
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
 	sigCh := make(chan os.Signal, 1)
 	signal.Notify(sigCh, syscall.SIGINT, syscall.SIGTERM)
-
 	go func() {
 		<-sigCh
 		cancel()
 	}()
 
-	agent.Run(ctx)
-}
+	agent.Run(ctx, cfg)
+}
+
+// ── db sub-commands ──────────────────────────────────────────────────────────
+
+func runDBCmd(args []string) {
+	if len(args) == 0 {
+		fmt.Fprintln(os.Stderr, "usage: bugswatch db <add|remove|list> [args]")
+		os.Exit(1)
+	}
+
+	// Allow --db-config as the first flag of a db sub-command.
+	cfgPath := config.DefaultDBConfigPath
+	if v := os.Getenv("BUGSWATCH_DB_CONFIG"); v != "" {
+		cfgPath = v
+	}
+	if len(args) >= 2 && args[0] == "--db-config" {
+		cfgPath = args[1]
+		args = args[2:]
+	}
+
+	switch args[0] {
+	case "add":
+		if len(args) < 3 {
+			fmt.Fprintln(os.Stderr, "usage: bugswatch db add <driver> <url>")
+			fmt.Fprintln(os.Stderr, "drivers: mysql, mariadb, postgres, redis, mongodb, sqlite")
+			os.Exit(1)
+		}
+		dbAdd(cfgPath, args[1], args[2])
+
+	case "remove":
+		if len(args) < 2 {
+			fmt.Fprintln(os.Stderr, "usage: bugswatch db remove <driver>")
+			os.Exit(1)
+		}
+		dbRemove(cfgPath, args[1])
+
+	case "list":
+		dbList(cfgPath)
+
+	default:
+		fmt.Fprintf(os.Stderr, "unknown db command %q\n", args[0])
+		os.Exit(1)
+	}
+}
+
+func dbAdd(cfgPath, driver, url string) {
+	entries, err := dbmanager.ReadEntries(cfgPath)
+	if err != nil {
+		log.Fatalf("read config: %v", err)
+	}
+
+	found := false
+	for i, e := range entries {
+		if e.Driver == driver {
+			entries[i].URL = url
+			found = true
+			break
+		}
+	}
+	if !found {
+		entries = append(entries, dbmanager.Entry{Driver: driver, URL: url})
+	}
+
+	if err := dbmanager.WriteEntries(cfgPath, entries); err != nil {
+		log.Fatalf("write config: %v", err)
+	}
+	fmt.Printf("added %s → %s\n", driver, cfgPath)
+}
+
+func dbRemove(cfgPath, driver string) {
+	entries, err := dbmanager.ReadEntries(cfgPath)
+	if err != nil {
+		log.Fatalf("read config: %v", err)
+	}
+
+	next := entries[:0]
+	for _, e := range entries {
+		if e.Driver != driver {
+			next = append(next, e)
+		}
+	}
+
+	if err := dbmanager.WriteEntries(cfgPath, next); err != nil {
+		log.Fatalf("write config: %v", err)
+	}
+	fmt.Printf("removed %s from %s\n", driver, cfgPath)
+}
+
+func dbList(cfgPath string) {
+	entries, err := dbmanager.ReadEntries(cfgPath)
+	if err != nil {
+		log.Fatalf("read config: %v", err)
+	}
+	if len(entries) == 0 {
+		fmt.Println("no database monitors configured")
+		return
+	}
+	enc := json.NewEncoder(os.Stdout)
+	enc.SetIndent("", "  ")
+	enc.Encode(entries)
+}