feat: add gateway config/update restart flow

src/infra/restart-sentinel.ts

@@ -0,0 +1,116 @@
+import fs from "node:fs/promises";
+import path from "node:path";
+
+import { resolveStateDir } from "../config/paths.js";
+
+export type RestartSentinelLog = {
+  stdoutTail?: string | null;
+  stderrTail?: string | null;
+  exitCode?: number | null;
+};
+
+export type RestartSentinelStep = {
+  name: string;
+  command: string;
+  cwd?: string | null;
+  durationMs?: number | null;
+  log?: RestartSentinelLog | null;
+};
+
+export type RestartSentinelStats = {
+  mode?: string;
+  root?: string;
+  before?: Record<string, unknown> | null;
+  after?: Record<string, unknown> | null;
+  steps?: RestartSentinelStep[];
+  reason?: string | null;
+  durationMs?: number | null;
+};
+
+export type RestartSentinelPayload = {
+  kind: "config-apply" | "update";
+  status: "ok" | "error" | "skipped";
+  ts: number;
+  sessionKey?: string;
+  message?: string | null;
+  stats?: RestartSentinelStats | null;
+};
+
+export type RestartSentinel = {
+  version: 1;
+  payload: RestartSentinelPayload;
+};
+
+const SENTINEL_FILENAME = "restart-sentinel.json";
+
+export function resolveRestartSentinelPath(
+  env: NodeJS.ProcessEnv = process.env,
+): string {
+  return path.join(resolveStateDir(env), SENTINEL_FILENAME);
+}
+
+export async function writeRestartSentinel(
+  payload: RestartSentinelPayload,
+  env: NodeJS.ProcessEnv = process.env,
+) {
+  const filePath = resolveRestartSentinelPath(env);
+  await fs.mkdir(path.dirname(filePath), { recursive: true });
+  const data: RestartSentinel = { version: 1, payload };
+  await fs.writeFile(filePath, `${JSON.stringify(data, null, 2)}\n`, "utf-8");
+  return filePath;
+}
+
+export async function readRestartSentinel(
+  env: NodeJS.ProcessEnv = process.env,
+): Promise<RestartSentinel | null> {
+  const filePath = resolveRestartSentinelPath(env);
+  try {
+    const raw = await fs.readFile(filePath, "utf-8");
+    let parsed: RestartSentinel | undefined;
+    try {
+      parsed = JSON.parse(raw) as RestartSentinel | undefined;
+    } catch {
+      await fs.unlink(filePath).catch(() => {});
+      return null;
+    }
+    if (!parsed || parsed.version !== 1 || !parsed.payload) {
+      await fs.unlink(filePath).catch(() => {});
+      return null;
+    }
+    return parsed;
+  } catch {
+    return null;
+  }
+}
+
+export async function consumeRestartSentinel(
+  env: NodeJS.ProcessEnv = process.env,
+): Promise<RestartSentinel | null> {
+  const filePath = resolveRestartSentinelPath(env);
+  const parsed = await readRestartSentinel(env);
+  if (!parsed) return null;
+  await fs.unlink(filePath).catch(() => {});
+  return parsed;
+}
+
+export function formatRestartSentinelMessage(
+  payload: RestartSentinelPayload,
+): string {
+  return `GatewayRestart:\n${JSON.stringify(payload, null, 2)}`;
+}
+
+export function summarizeRestartSentinel(
+  payload: RestartSentinelPayload,
+): string {
+  const kind = payload.kind;
+  const status = payload.status;
+  const mode = payload.stats?.mode ? ` (${payload.stats.mode})` : "";
+  return `Gateway restart ${kind} ${status}${mode}`.trim();
+}
+
+export function trimLogTail(input?: string | null, maxChars = 8000) {
+  if (!input) return null;
+  const text = input.trimEnd();
+  if (text.length <= maxChars) return text;
+  return `…${text.slice(text.length - maxChars)}`;
+}