build: agent is the image's default entrypoint; drop the old server examples (#7)

cmd/agent/main.go

@@ -16,6 +16,7 @@ import (
 	"github.com/shcizo/package-updater/internal/agent/config"
 	"github.com/shcizo/package-updater/internal/agent/conn"
 	"github.com/shcizo/package-updater/internal/agent/inventory"
+	"github.com/shcizo/package-updater/internal/agent/updater"
 	"github.com/shcizo/package-updater/internal/logging"
 )
 
@@ -42,19 +43,45 @@ func run() error {
 	}
 	defer dockerCli.Close()
 
+	auth, err := updater.LoadRegistryAuth(cfg.DockerConfig, logger)
+	if err != nil {
+		return fmt.Errorf("registry auth: %w", err)
+	}
+	resolver := updater.NewResolver(dockerCli, auth)
+	exec := updater.NewDispatch(
+		updater.NewComposeExecutor(dockerCli, resolver, cfg.SelfID, updater.ExecDocker),
+		updater.NewSwarmExecutor(dockerCli, resolver, auth),
+	)
+	runner := updater.NewRunner(exec, cfg.UpdateTimeout)
+
 	collector := inventory.New(dockerCli, cfg.SelfID)
 	agent := conn.New(conn.Config{
 		URL: cfg.MasterURL, Token: cfg.Token, Fingerprint: cfg.MasterKey, Version: version,
-	}, collector, logger)
+	}, collector, runner, logger)
 
 	ctx, stop := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
 	defer stop()
 
+	logMounts(ctx, dockerCli, cfg.SelfID, logger)
+	go runner.Run(ctx)
 	go watchLoop(ctx, dockerCli, agent, logger)
-	logger.Info("agent_starting", "version", version, "master_url", cfg.MasterURL)
+	logger.Info("agent_starting", "version", version, "master_url", cfg.MasterURL,
+		"update_timeout", cfg.UpdateTimeout.String(), "registry_auth", auth != nil)
 	return agent.Run(ctx)
 }
 
+// logMounts warns at startup when Compose updates cannot work. Each job reads
+// the mounts again itself; this is only for the operator.
+func logMounts(ctx context.Context, cli updater.SelfInspector, selfID string, log *slog.Logger) {
+	roots, err := updater.MountRoots(ctx, cli, selfID)
+	if err != nil || len(roots) == 0 {
+		log.Warn("no_stack_mounts", "error", err,
+			"hint", "Compose updates will fail; mount each stacks directory at the same path, read-write")
+		return
+	}
+	log.Info("stack_mounts", "roots", roots)
+}
+
 // watchLoop keeps a Docker event subscription alive. When the stream breaks
 // (daemon restart), it resubscribes and asks for a refresh, because events
 // may have been missed in between. It also asks for a full re-inventory every