Add lavinmq amqp provider and amqp-ping consumer

lavinmq becomes a provider of a user-facing amqp interface: a consumer
that requires a message queue is given its OWN broker — a scoped vhost
and user on a lavinmq provider — not an account on the mesh's own
control-plane broker (ADR 0048). Vhost-per-login is the isolation model,
the exact analog of postgres's database-per-login: the provider names a
vhost after the consumer's login and a user with full rights on that
vhost and none elsewhere, so a login is a broker the consumer alone can
reach.

The provider drives lavinmq through its HTTP management API (client.ts,
the module's one impure seam), with a run-once bootstrap that computes
the RabbitMQ-compatible password hash lavinmq's config wants from the
plain admin secret the mesh mints — the value no ${secret:...}
placeholder can produce and the reason the bootstrap exists (ADR 0052).
serves.amqp carries the port so consumers reference ${bound:amqp:port}.

amqp-ping is a demo consumer: it contributes nothing (the vhost is the
login), reads its grant from an env-file the mesh fills, and uses
${bound:amqp:as} for BOTH its username and its vhost — the db-name
lesson applied to AMQP. It speaks AMQP 0-9-1 over a raw socket with no
npm dependency (the way redis speaks RESP) and round-trips one message.
It carries a slug so its identity fits the 20-char backend bound
(ADR 0049).

Claude-Session: https://claude.ai/code/session_01LrgweAeERJYBg88c5cKDzF

modules/lavinmq/bootstrap/index.ts

@@ -0,0 +1,45 @@
+// lavinmq's run-once bootstrap — lavinmq's own code (novox/hq ADR 0039), run once before the broker
+// first starts (ADR 0052). lavinmq's default admin is set at first boot from a config file's
+// `default_password_hash`, and that value is a HASH of the mesh-minted admin password, not the
+// password itself — a form the mesh's plain-secret delivery cannot produce and no `${secret:...}`
+// placeholder can compute. So this step computes it: it reads the admin password the mesh minted and
+// the host unsealed, hashes it the way lavinmq expects (see client.rabbitHash), and writes the config
+// file the broker container reads with `--config`. The host runs it to completion and only then
+// starts the broker the manifest places after it — so the broker's first boot finds a config with an
+// admin it can authenticate, and the provisioner (which reaches the management API as that admin)
+// can do its work.
+//
+// It runs in the module's own runtime image, under the module's own account, as `mesh-tools run`
+// imports it — no broker connection, because writing a config file is an offline operation and there
+// is no broker to reach yet.
+//
+// lavinmq consults `default_user`/`default_password_hash` only on a first boot with an empty data
+// dir; a later boot uses the persisted user database and ignores them. So this seeds the admin once,
+// and a rotation of the admin secret does not re-key an already-initialised broker — the same
+// first-boot-only shape the RabbitMQ-compatible default user has always had.
+
+import { writeFileSync } from "node:fs";
+import { readFileSync } from "node:fs";
+import { rabbitHash } from "../client.js";
+
+const adminUser = process.env.MESH_PROVISION_ADMIN_USER ?? process.env.MESH_LAVINMQ_ADMIN_USER ?? "mesh-admin";
+const passwordFile = process.env.MESH_PROVISION_PASSWORD_FILE ?? process.env.MESH_LAVINMQ_ADMIN_PASSWORD_FILE ?? "/run/secrets/default";
+const configOut = process.env.MESH_LAVINMQ_CONFIG_OUT ?? "/var/lib/lavinmq-module/lavinmq.ini";
+const dataDir = process.env.MESH_LAVINMQ_DATA_DIR ?? "/var/lib/lavinmq";
+
+const password = readFileSync(passwordFile, "utf8").replace(/\n$/, "");
+if (!password) {
+  throw new Error(`[lavinmq:bootstrap] admin password file ${passwordFile} is empty — cannot seed the admin`);
+}
+
+// The broker reads only what it needs to authenticate its admin on first boot; bind/ports come from
+// the container's entrypoint (`-b 0.0.0.0`), so this file names the admin and nothing else about the
+// network.
+const ini =
+  "[main]\n" +
+  `data_dir = ${dataDir}\n` +
+  `default_user = ${adminUser}\n` +
+  `default_password_hash = ${rabbitHash(password)}\n`;
+
+writeFileSync(configOut, ini, { mode: 0o600 });
+console.log(`[lavinmq:bootstrap] wrote ${configOut} with admin '${adminUser}' (password hashed for lavinmq)`);

modules/lavinmq/client.ts

@@ -0,0 +1,150 @@
+// lavinmq's admin client — lavinmq's own code, living in the module (novox/hq ADR 0039). Both this
+// module's tools and its provisioner import it, and nothing outside lavinmq does.
+//
+// It drives lavinmq through its HTTP management API (the RabbitMQ-compatible surface lavinmq serves
+// on 15672), not a hand-rolled AMQP admin stack: the module may take NO npm dependency beyond
+// @novox/mesh-sdk, and the management API is exactly the admin surface — create/remove a vhost, a
+// user, and its permissions — reached with `fetch` (global on node 22) and HTTP Basic auth. One
+// boundary, `api()`, and every method is built on it. This is the module's one impure seam, the way
+// postgres's is `psql` and redis's is a RESP socket.
+//
+// **The login and password are the mesh's, not the provisioner's (novox/hq ADR 0048).** The mesh
+// derives the login and hands it to both ends so they agree, and mints the password and delivers a
+// copy to each. lavinmq creates exactly that user with exactly that password on a vhost of the same
+// name — a name or password the provisioner invented is one the consumer could never present.
+
+import { createHash, randomBytes } from "node:crypto";
+import { readFileSync } from "node:fs";
+
+export interface LavinmqConn {
+  /** Base URL of the management API, e.g. http://lavinmq:15672 (no trailing /api). */
+  readonly base: string;
+  readonly adminUser: string;
+  readonly adminPassword: string;
+}
+
+export class LavinmqClient {
+  constructor(private readonly conn: LavinmqConn) {}
+
+  /**
+   * Build from the module's resolved environment. Reads MESH_LAVINMQ_* first (the documented
+   * names), falling back to the MESH_PROVISION_* keys the manifest already sets on the provisioner
+   * container so the module runs unchanged there. Throws if it cannot find a management endpoint and
+   * an admin password — the right failure, because without them nothing it does can work.
+   */
+  static fromEnv(env: NodeJS.ProcessEnv = process.env): LavinmqClient {
+    const base = (env.MESH_LAVINMQ_MANAGEMENT ?? env.MESH_PROVISION_LAVINMQ ?? "").replace(/\/+$/, "");
+    const adminUser = env.MESH_LAVINMQ_ADMIN_USER ?? env.MESH_PROVISION_ADMIN_USER ?? "mesh-admin";
+    const adminPassword = env.MESH_LAVINMQ_ADMIN_PASSWORD ?? readSecretFile(env.MESH_PROVISION_PASSWORD_FILE);
+    if (!base || !adminPassword) {
+      throw new Error("lavinmq management endpoint or admin password is not set — lavinmq's own code cannot reach the server");
+    }
+    return new LavinmqClient({ base, adminUser, adminPassword });
+  }
+
+  /** One request against the management API. A non-2xx reply rejects, carrying the body for the log. */
+  async api(method: string, path: string, body?: unknown): Promise<unknown> {
+    const headers: Record<string, string> = {
+      Authorization: "Basic " + Buffer.from(`${this.conn.adminUser}:${this.conn.adminPassword}`).toString("base64"),
+    };
+    if (body !== undefined) headers["Content-Type"] = "application/json";
+    const resp = await fetch(`${this.conn.base}/api${path}`, {
+      method,
+      headers,
+      body: body !== undefined ? JSON.stringify(body) : undefined,
+    });
+    if (!resp.ok) {
+      throw new Error(`lavinmq management API ${method} ${path} -> ${resp.status}: ${await resp.text()}`);
+    }
+    const text = await resp.text();
+    return text ? JSON.parse(text) : null;
+  }
+
+  /** True once the management API answers — the server has finished starting. */
+  async ready(): Promise<boolean> {
+    try {
+      await this.api("GET", "/overview");
+      return true;
+    } catch {
+      return false;
+    }
+  }
+
+  /** Block until the management API answers, or throw once the budget is spent. */
+  async waitReady(retries = 30, delayMs = 1000): Promise<void> {
+    for (let i = 0; i < retries; i++) {
+      if (await this.ready()) return;
+      await new Promise((r) => setTimeout(r, delayMs));
+    }
+    throw new Error("lavinmq management API did not become ready");
+  }
+
+  /**
+   * Create (or reset to a known state) one consumer's broker: a vhost and a user both named for the
+   * consumer's login, with the login owning full permissions on exactly that vhost. Idempotent — a
+   * PUT of a vhost or user that exists is a no-op or a password reset, so a reconcile can call it
+   * again without harm. The consumer connects as `<login>` to vhost `<login>` and can reach nothing
+   * else (novox/hq ADR 0048).
+   */
+  async createConsumer(login: string, password: string): Promise<void> {
+    const v = encodeURIComponent(login);
+    const u = encodeURIComponent(login);
+    await this.api("PUT", `/vhosts/${v}`);
+    await this.api("PUT", `/users/${u}`, { password, tags: "" });
+    await this.api("PUT", `/permissions/${v}/${u}`, { configure: ".*", write: ".*", read: ".*" });
+  }
+
+  /** Remove a consumer's vhost and user, idempotently. A DELETE of what is already gone is tolerated. */
+  async removeConsumer(login: string): Promise<void> {
+    const v = encodeURIComponent(login);
+    const u = encodeURIComponent(login);
+    try {
+      await this.api("DELETE", `/vhosts/${v}`);
+    } catch (err) {
+      console.error(`[lavinmq] delete vhost ${login} failed (continuing): ${err}`);
+    }
+    try {
+      await this.api("DELETE", `/users/${u}`);
+    } catch (err) {
+      console.error(`[lavinmq] delete user ${login} failed (continuing): ${err}`);
+    }
+  }
+
+  /** The vhosts, for the amqp_list_vhosts tool. */
+  async listVhosts(): Promise<{ name: string; messages: number }[]> {
+    const vhosts = (await this.api("GET", "/vhosts")) as { name: string; messages?: number }[];
+    return vhosts.map((v) => ({ name: v.name, messages: v.messages ?? 0 }));
+  }
+
+  /** The queues on one vhost (default the root vhost), for the amqp_list_queues tool. */
+  async listQueues(vhost = "/"): Promise<{ name: string; messages: number; consumers: number }[]> {
+    const queues = (await this.api("GET", `/queues/${encodeURIComponent(vhost)}`)) as
+      { name: string; messages?: number; consumers?: number }[];
+    return queues.map((q) => ({ name: q.name, messages: q.messages ?? 0, consumers: q.consumers ?? 0 }));
+  }
+}
+
+/**
+ * The RabbitMQ-compatible SHA-256 password hash lavinmq's `default_password_hash` expects:
+ * base64( salt[4] || sha256( salt || utf8(password) ) ). The salt is any four bytes — random here,
+ * because a fixed salt buys nothing and a fresh one is free. Verified against `lavinmqctl
+ * hash_password`: a hash produced here is accepted by the server unchanged.
+ */
+export function rabbitHash(password: string, salt: Buffer = randomBytes(4)): string {
+  const digest = createHash("sha256").update(Buffer.concat([salt, Buffer.from(password, "utf8")])).digest();
+  return Buffer.concat([salt, digest]).toString("base64");
+}
+
+/** Generate a URL-safe password. */
+export function generatePassword(): string {
+  return randomBytes(24).toString("base64url");
+}
+
+function readSecretFile(path: string | undefined): string | undefined {
+  if (!path) return undefined;
+  try {
+    return readFileSync(path, "utf8").trim();
+  } catch {
+    return undefined;
+  }
+}

modules/lavinmq/index.ts

@@ -0,0 +1,25 @@
+// lavinmq's events entrypoint, loaded by the per-node tool host (the provisioner container runs
+// ./provisioner separately). The broker lifecycle events are EMITTED from the provisioner, where the
+// lifecycle actually happens (novox/hq ADR 0041/0042):
+//   module.lavinmq.amqp.provisioned    — a consumer's vhost + user was created
+//   module.lavinmq.amqp.deprovisioned  — that vhost + user was removed
+// Here in the tool host we react to them, keeping a lightweight audit trail of who was granted a
+// broker and who lost one — observability the provider itself is best placed to log.
+
+import { on } from "@novox/mesh-sdk/events";
+
+interface AmqpEvent {
+  consumer?: string;
+  user: string;
+  vhost?: string;
+}
+
+await on<AmqpEvent>("module.lavinmq.amqp.provisioned", async (e) => {
+  console.log(`[lavinmq] broker provisioned for ${e.body.consumer ?? "?"} (user ${e.body.user}, vhost ${e.body.vhost})`);
+});
+
+await on<AmqpEvent>("module.lavinmq.amqp.deprovisioned", async (e) => {
+  console.log(`[lavinmq] broker deprovisioned (user ${e.body.user})`);
+});
+
+console.log("[lavinmq] auditing broker lifecycle events");

modules/lavinmq/module.json

@@ -0,0 +1,133 @@
+{
+  "module": "lavinmq",
+  "version": "1",
+  "provides": [
+    {
+      "name": "amqp",
+      "scope": "mesh"
+    }
+  ],
+  "capabilities": [
+    "container-runtime"
+  ],
+  "emits": [
+    "module.lavinmq.amqp.provisioned",
+    "module.lavinmq.amqp.deprovisioned"
+  ],
+  "consumes": [
+    "module.lavinmq.amqp.provisioned",
+    "module.lavinmq.amqp.deprovisioned"
+  ],
+  "serves": {
+    "amqp": {
+      "port": 5672
+    }
+  },
+  "receives": {
+    "amqp": "/var/lib/lavinmq-module/grants/mesh.json"
+  },
+  "grants": {
+    "amqp": "/var/lib/lavinmq-module/grants"
+  },
+  "own-secrets": {
+    "default": "/var/lib/lavinmq-module/default.secret",
+    "broker": "/var/lib/mesh/lavinmq/broker"
+  },
+  "listens": [
+    {
+      "port": 5672,
+      "protocol": "tcp",
+      "from": "mesh",
+      "why": "modules on any machine that were granted a queue"
+    }
+  ],
+  "resources": [
+    {
+      "id": "mesh-state",
+      "type": "directory",
+      "path": "/var/lib/mesh/lavinmq",
+      "mode": "0700"
+    },
+    {
+      "id": "state",
+      "type": "directory",
+      "path": "/var/lib/lavinmq-module",
+      "mode": "0700"
+    },
+    {
+      "id": "grants-dir",
+      "type": "directory",
+      "path": "/var/lib/lavinmq-module/grants",
+      "mode": "0700"
+    },
+    {
+      "id": "data",
+      "type": "directory",
+      "path": "/services/lavinmq/data",
+      "mode": "0700"
+    },
+    {
+      "id": "net",
+      "type": "network",
+      "name": "lavinmq"
+    },
+    {
+      "id": "bootstrap",
+      "type": "container",
+      "name": "lavinmq-bootstrap",
+      "image": "mesh-runtime-lavinmq@sha256:0000000000000000000000000000000000000000000000000000000000000000",
+      "run-once": true,
+      "volumes": [
+        "/var/lib/lavinmq-module:/var/lib/lavinmq-module",
+        "/var/lib/lavinmq-module/default.secret:/run/secrets/default:ro"
+      ],
+      "env": {
+        "MESH_PROVISION_ADMIN_USER": "mesh-admin",
+        "MESH_PROVISION_PASSWORD_FILE": "/run/secrets/default",
+        "MESH_LAVINMQ_CONFIG_OUT": "/var/lib/lavinmq-module/lavinmq.ini",
+        "MESH_LAVINMQ_DATA_DIR": "/var/lib/lavinmq"
+      },
+      "args": [
+        "run",
+        "/app/modules/lavinmq/dist/bootstrap/index.js"
+      ]
+    },
+    {
+      "id": "server",
+      "type": "container",
+      "name": "lavinmq",
+      "image": "cloudamqp/lavinmq@sha256:3eb54c12916d700a978c2ea86e6362cd4974b0e3189508718006d4e6d341246b",
+      "network": "lavinmq",
+      "ports": [
+        "5672"
+      ],
+      "volumes": [
+        "/services/lavinmq/data:/var/lib/lavinmq",
+        "/var/lib/lavinmq-module/lavinmq.ini:/etc/lavinmq/lavinmq.ini:ro"
+      ],
+      "args": [
+        "--config",
+        "/etc/lavinmq/lavinmq.ini"
+      ]
+    },
+    {
+      "id": "runtime",
+      "type": "container",
+      "name": "mesh-lavinmq",
+      "image": "mesh-runtime-lavinmq@sha256:0000000000000000000000000000000000000000000000000000000000000000",
+      "network": "lavinmq",
+      "volumes": [
+        "/var/lib/mesh/lavinmq/broker:/run/secrets/broker:ro",
+        "/var/lib/lavinmq-module/grants:/var/lib/lavinmq-module/grants:ro",
+        "/var/lib/lavinmq-module/default.secret:/run/secrets/default:ro"
+      ],
+      "env": {
+        "MESH_BROKER_FILE": "/run/secrets/broker",
+        "MESH_RECEIVES": "/var/lib/lavinmq-module/grants/mesh.json",
+        "MESH_PROVISION_LAVINMQ": "http://lavinmq:15672",
+        "MESH_PROVISION_ADMIN_USER": "mesh-admin",
+        "MESH_PROVISION_PASSWORD_FILE": "/run/secrets/default"
+      }
+    }
+  ]
+}

modules/lavinmq/package.json

@@ -0,0 +1,14 @@
+{
+  "name": "@novox/module-lavinmq",
+  "version": "0.1.0",
+  "description": "lavinmq — provides the mesh amqp interface (a per-consumer AMQP message broker). Its management client, provisioner, run-once bootstrap, tools and events live here (novox/hq ADR 0039).",
+  "type": "module",
+  "private": true,
+  "dependencies": {
+    "@novox/mesh-sdk": "^0.1.0"
+  },
+  "devDependencies": {
+    "@types/node": "^22.0.0",
+    "typescript": "^5.6.0"
+  }
+}

modules/lavinmq/provisioner/index.ts

@@ -0,0 +1,51 @@
+// lavinmq's provisioner — the adapter that makes lavinmq a provider of the mesh `amqp` interface.
+// The reconcile loop, the contributions file, and reading the mesh's minted password are the sdk
+// harness's; this writes only the per-service half: how lavinmq creates and removes a consumer's own
+// broker (novox/hq ADR 0039/0040/0048).
+//
+// The `amqp` interface: a consumer connects as `as` with the password the mesh minted, to a vhost
+// named for that same login — its own message broker, isolated from every other consumer's by the
+// vhost boundary. It is a broker of its own, not a shared account on the mesh's control-plane broker.
+//
+// **The login and password are the mesh's, not the provisioner's (novox/hq ADR 0048).** The mesh
+// derives the login and hands it to both ends so they agree, and mints the password and delivers a
+// copy to each. lavinmq creates exactly that user with exactly that password — a name or password the
+// provisioner invented is one the consumer could never present.
+//
+// Vhost-per-login is the isolation model, the exact analog of postgres's database-per-login: the
+// consumer owns one vhost, named for its login, and a user with full rights on that vhost and no
+// rights anywhere else. lavinmq enforces it — a user with no permission on `/` is refused the moment
+// it opens that vhost (`NOT_ALLOWED`), so a login is a broker the consumer alone can reach.
+
+import { runProvisioner, type Provision } from "@novox/mesh-sdk/provisioner";
+import { emit } from "@novox/mesh-sdk/events";
+import { LavinmqClient } from "../client.js";
+
+const lavinmq = LavinmqClient.fromEnv();
+
+/** Emit a lifecycle event without letting a broker hiccup fail the provisioning itself. */
+async function announce(type: string, body: Record<string, string>): Promise<void> {
+  try {
+    await emit(type, body);
+  } catch (err) {
+    console.error(`[provisioner:amqp] emit ${type} failed: ${err}`);
+  }
+}
+
+runProvisioner("amqp", {
+  async create(p: Provision): Promise<void> {
+    // The vhost and the user share the consumer's login, so one cannot reach another's broker.
+    await lavinmq.waitReady();
+    await lavinmq.createConsumer(p.as, p.password);
+    await announce("module.lavinmq.amqp.provisioned", {
+      consumer: p.consumer ?? "",
+      user: p.as,
+      vhost: p.as,
+    });
+  },
+
+  async remove(p: { as: string }): Promise<void> {
+    await lavinmq.removeConsumer(p.as);
+    await announce("module.lavinmq.amqp.deprovisioned", { user: p.as, vhost: p.as });
+  },
+});

modules/lavinmq/tools/index.ts

@@ -0,0 +1,32 @@
+// lavinmq's tools — lavinmq's own code (novox/hq ADR 0039), importing lavinmq's own management
+// client. They return structured data; the mesh serves them through the sdk's tool harness.
+
+import { registerModuleTools, type ToolDefinition } from "@novox/mesh-sdk/tools";
+import { LavinmqClient } from "../client.js";
+
+export function getLavinmqTools(lavinmq: LavinmqClient): ToolDefinition[] {
+  return [
+    {
+      name: "amqp_list_vhosts",
+      description: "List the lavinmq virtual hosts — one per consumer that was granted a broker.",
+      input: {},
+      run: async () => ({ vhosts: await lavinmq.listVhosts() }),
+    },
+    {
+      name: "amqp_list_queues",
+      description: "List the queues on a vhost with message and consumer counts. Omit vhost for the root '/'.",
+      input: { vhost: { type: "string", description: "the vhost to list, e.g. a consumer's login; defaults to '/'" } },
+      run: async (args) => ({ queues: await lavinmq.listQueues(args.vhost ? String(args.vhost) : undefined) }),
+    },
+  ];
+}
+
+// The tools exist only when the server can be reached from the environment; without it, lavinmq
+// contributes none rather than failing the whole tool runtime.
+registerModuleTools("lavinmq", (env) => {
+  try {
+    return getLavinmqTools(LavinmqClient.fromEnv(env));
+  } catch {
+    return [];
+  }
+});

modules/lavinmq/tsconfig.json

@@ -0,0 +1,12 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "NodeNext",
+    "moduleResolution": "NodeNext",
+    "strict": true,
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "noEmit": true
+  },
+  "include": ["client.ts", "index.ts", "provisioner/index.ts", "tools/index.ts", "bootstrap/index.ts"]
+}