mosquitto: a consumer's grant is the topics it asks for, and its binding says the port

mqtt-topic served nothing: with two listens the mesh could not say which port a consumer dials, so a
consumer had to type 1883 into its config. It now serves the MQTT listener's port (the machine's,
once assigned) and the scheme, so `${bound:mqtt-topic:port}` fills.

The provisioner confined every consumer to `<as>/#`, which leaves nothing for the consumers the
broker exists for: Home Assistant discovers under homeassistant/# and tasmota/discovery/#, and
Node-RED's flows follow the devices' own topics. A consumer now contributes `topics` (MQTT topic
filters) to its mqtt-topic requirement and is granted exactly those; with none, its own subtree as
before. Settings merge into contributions, so an operator narrows a grant per assignment. The role
is brought to exactly the wanted ACLs (stale ones removed), `holds` checks the ACLs too, and an
invalid list is refused, never quietly narrowed. Only the role named for the consumer is touched:
a client carried from the predecessor's password file keeps its own.

modules/baserow/client.ts

@@ -2,15 +2,12 @@
 // module's tools and anything else baserow-specific import it; nothing outside baserow does.
 //
 // Baserow authenticates a person with email + password, exchanged for a JWT at /api/user/token-auth/.
-// The standard image creates no admin from env, so the account is one a person made in Baserow: its
-// password is the module's `admin` secret, accepted from the operator, and its email and the public
-// host Baserow answers to reach the runtime config file the mesh mounts (the email from the
-// assignment's settings). Until both are there fromEnv throws and the module exposes no tools — the
-// same dormant-until-configured shape gitea uses for its token.
+// Those credentials are the mesh's own: a person signs up in Baserow (the standard image creates no
+// admin from env), and the credential is placed in the runtime config file the mesh mounts. Until
+// that happens fromEnv throws and the module simply exposes no tools — the same dormant-until-
+// configured shape gitea uses for its token.
 
 import { readFileSync } from "node:fs";
-import { request as httpRequest } from "node:http";
-import { request as httpsRequest } from "node:https";
 
 export interface BaserowApplication {
   id: number;
@@ -71,63 +68,35 @@ export class BaserowClient {
     return h;
   }
 
-  /**
-   * One HTTP exchange. Not `fetch`: Node's fetch drops a caller's Host header and sends the URL's
-   * own, and Baserow answers only the host of its BASEROW_PUBLIC_URL — any other Host is looked up
-   * as a published builder site and gets 404, `/api/_health/` included. A co-located caller reaching
-   * it by container name must present the public host, so the request is made with node:http, which
-   * sends the Host it is given.
-   */
-  private send(path: string, method: string, headers: Record<string, string>, body?: string): Promise<{ status: number; text: string }> {
-    const url = new URL(`${this.baseUrl}${path}`);
-    const request = url.protocol === "https:" ? httpsRequest : httpRequest;
-    // A length, never chunked: Baserow's server reads a chunked body as empty.
-    const sent = body === undefined ? headers : { ...headers, "Content-Length": String(Buffer.byteLength(body)) };
-    return new Promise((resolve, reject) => {
-      const req = request(url, { method, headers: sent }, (res) => {
-        let text = "";
-        res.setEncoding("utf8");
-        res.on("data", (chunk: string) => (text += chunk));
-        res.on("end", () => resolve({ status: res.statusCode ?? 0, text }));
-        res.on("error", reject);
-      });
-      req.on("error", reject);
-      if (body !== undefined) req.write(body);
-      req.end();
-    });
-  }
-
-  /** Exchange email + password for a JWT, caching it until Baserow refuses it. Handles both the
+  /** Exchange email + password for a JWT, caching it for the client's lifetime. Handles both the
    *  older `{ token }` and the newer `{ access_token }` response shapes. */
   async authenticate(): Promise<string> {
     if (this.token) return this.token;
-    const res = await this.send(
-      "/api/user/token-auth/",
-      "POST",
-      this.headers(),
-      JSON.stringify({ email: this.email, password: this.password }),
-    );
-    if (res.status < 200 || res.status >= 300) throw new Error(`baserow auth failed: ${res.status} ${res.text}`);
-    const data = JSON.parse(res.text) as { token?: string; access_token?: string };
+    const res = await fetch(`${this.baseUrl}/api/user/token-auth/`, {
+      method: "POST",
+      headers: this.headers(),
+      body: JSON.stringify({ email: this.email, password: this.password }),
+    });
+    if (!res.ok) throw new Error(`baserow auth failed: ${res.status} ${await res.text()}`);
+    const data = (await res.json()) as { token?: string; access_token?: string };
     const token = data.access_token ?? data.token;
     if (!token) throw new Error("baserow auth returned no token");
     this.token = token;
     return token;
   }
 
-  /** An authenticated GET. A refused token is dropped and the call made once more with a fresh one:
-   *  Baserow's access tokens expire after minutes, and the runtime lives for weeks. */
-  private async authed<T>(path: string): Promise<T> {
-    for (let attempt = 0; ; attempt++) {
-      const token = await this.authenticate();
-      const res = await this.send(path, "GET", this.headers({ Authorization: `JWT ${token}` }));
-      if (res.status === 401 && attempt === 0) {
-        this.token = null;
-        continue;
-      }
-      if (res.status < 200 || res.status >= 300) throw new Error(`baserow ${path}: ${res.status} ${res.text}`);
-      return (res.text ? JSON.parse(res.text) : null) as T;
-    }
+  private async authed<T>(path: string, options: RequestInit = {}): Promise<T> {
+    const token = await this.authenticate();
+    const res = await fetch(`${this.baseUrl}${path}`, {
+      ...options,
+      headers: this.headers({
+        Authorization: `JWT ${token}`,
+        ...(options.headers as Record<string, string> | undefined),
+      }),
+    });
+    if (!res.ok) throw new Error(`baserow ${path}: ${res.status} ${await res.text()}`);
+    const text = await res.text();
+    return (text ? JSON.parse(text) : null) as T;
   }
 
   /** The applications (databases) the account can see, across all its workspaces. */

modules/baserow/module.json

@@ -18,14 +18,14 @@
     }
   },
   "binds": {
-    "postgres-database": "${dir:state}/database.json",
-    "route": "${dir:state}/route.json"
+    "postgres-database": "/var/lib/baserow/database.json",
+    "route": "/var/lib/baserow/route.json"
   },
   "secrets": {
-    "postgres-database": "${dir:state}/database.secret"
+    "postgres-database": "/var/lib/baserow/database.secret"
   },
   "own-secrets": {
-    "admin": "${dir:state}/admin.secret",
+    "secret-key": "/var/lib/baserow/secret-key.secret",
     "broker": "/var/lib/mesh/baserow/broker"
   },
   "listens": [
@@ -34,7 +34,7 @@
       "port": 80,
       "protocol": "tcp",
       "from": "mesh",
-      "why": "the Baserow web UI and REST API, served by the image's own Caddy; a public name is the route's"
+      "why": "the Baserow web UI and REST API; a public name is a route grant later"
     }
   ],
   "resources": [
@@ -47,21 +47,22 @@
     {
       "id": "state",
       "type": "directory",
-      "mode": "0700",
-      "place": "."
+      "path": "/var/lib/baserow",
+      "mode": "0700"
     },
     {
       "id": "data",
       "type": "directory",
+      "path": "/services/baserow/data",
       "mode": "0755",
       "owner": "9999:9999"
     },
     {
       "id": "server-env",
       "type": "file",
-      "path": "${dir:state}/server.env",
+      "path": "/var/lib/baserow/server.env",
       "mode": "0600",
-      "content": "DATABASE_HOST=${bound:postgres-database:at}\nDATABASE_PORT=${bound:postgres-database:port}\nDATABASE_NAME=${bound:postgres-database:as}\nDATABASE_USER=${bound:postgres-database:as}\nDATABASE_PASSWORD_FILE=/run/secrets/database\nDISABLE_EMBEDDED_PSQL=true\nBASEROW_PUBLIC_URL=https://${bound:route:name}\n"
+      "content": "DATABASE_HOST=${bound:postgres-database:at}\nDATABASE_PORT=${bound:postgres-database:port}\nDATABASE_NAME=${bound:postgres-database:as}\nDATABASE_USER=${bound:postgres-database:as}\nDATABASE_PASSWORD=${secret:postgres-database}\nSECRET_KEY=${secret:secret-key}\nBASEROW_PUBLIC_URL=http://localhost\n"
     },
     {
       "id": "net",
@@ -72,25 +73,25 @@
       "id": "server",
       "type": "container",
       "name": "baserow",
-      "image": "baserow/baserow@sha256:263ea6c4b72c9eccabcd975ffe9fdebf23913a293a514bec6a3897a5e0a5a080",
+      "image": "baserow/baserow@sha256:834424a10413798567f76428f255dc259445b7f8dcec56598c05b4073bb2a124",
       "network": "baserow",
       "env-file": [
-        "${dir:state}/server.env"
+        "/var/lib/baserow/server.env"
       ],
       "ports": [
         "80"
       ],
       "volumes": [
-        "${dir:data}:/baserow/data",
-        "${dir:state}/database.secret:/run/secrets/database:ro"
-      ]
+        "/services/baserow/data:/baserow/data"
+      ],
+      "secrets-in-environment": "baserow reads DATABASE_PASSWORD and SECRET_KEY with os.getenv and has no _FILE twin (settings/base.py); not convertible"
     },
     {
       "id": "runtime-config",
       "type": "file",
       "path": "/var/lib/mesh/baserow/config.json",
       "mode": "0600",
-      "content": "{\n  \"password\": \"${secret:admin}\",\n  \"host\": \"${bound:route:name}\"\n}\n",
+      "content": "{}\n",
       "merge": "json"
     },
     {

modules/mosquitto/Dockerfile

@@ -13,7 +13,7 @@ ARG RUNTIME_BASE
 FROM ${BUILD_BASE} AS build
 WORKDIR /app/modules/mosquitto
 COPY . .
-RUN node /app/node_modules/typescript/bin/tsc client.ts index.ts tools/index.ts provisioner/index.ts bootstrap/index.ts \
+RUN node /app/node_modules/typescript/bin/tsc topics.ts client.ts index.ts tools/index.ts provisioner/index.ts bootstrap/index.ts \
       --module NodeNext --moduleResolution NodeNext --target ES2022 --outDir dist
 
 FROM ${RUNTIME_BASE}

modules/mosquitto/client.ts

@@ -20,6 +20,8 @@ import { readFileSync } from "node:fs";
 import { execFile } from "node:child_process";
 import { promisify } from "node:util";
 
+import { missingAcls, parseRoleAcls, staleAcls, wantedAcls } from "./topics.js";
+
 const run = promisify(execFile);
 
 export interface MqttConn {
@@ -141,14 +143,19 @@ export class MosquittoClient {
   }
 
   /**
-   * Create (or reset to a known state) a client scoped to one topic namespace, idempotently. The
-   * client is confined to `<prefix>/#` by a same-named role: it may publish to, subscribe to and
-   * receive on exactly its own subtree and nothing else — the MQTT analog of redis's keyspace-scoped
-   * ACL user. Called again for an existing client, it resets the password and re-asserts the ACLs.
+   * Create (or reset to a known state) a client granted exactly these topic filters, idempotently.
+   * The grant is a same-named role carrying, for every filter, publish, receive and subscribe — and
+   * nothing else: an ACL the role carries that the filters no longer name is removed, so narrowing a
+   * consumer's `topics` narrows what it may do. By default the filters are the consumer's own
+   * subtree, `<as>/#` (see topics.ts). Called again for an existing client, it resets the password
+   * and re-asserts the ACLs.
+   *
+   * Only the role named for this client is ever changed. A client or role the mesh did not make —
+   * a device carried from the predecessor's password file, its `legacy-full-access` role — is never
+   * read, changed or removed here.
    */
-  async createScopedClient(username: string, password: string, topicPrefix: string): Promise<void> {
+  async createScopedClient(username: string, password: string, filters: readonly string[]): Promise<void> {
     const role = username; // one role per client, named for it
-    const pattern = `${topicPrefix}/#`;
 
     if (await this.clientExists(username)) {
       await this.ctl("setClientPassword", username, password);
@@ -161,17 +168,18 @@ export class MosquittoClient {
       await this.ctl("createClient", username, "-p", password);
     }
 
-    // A role carrying exactly this client's topic ACLs. createRole, addRoleACL and addClientRole are
-    // all one-shot: each rejects with an "already exists" when re-run against a role/ACL/binding it
-    // created on a previous reconcile. That rejection is the intended terminal state — the ACL is
-    // deterministic (`<prefix>/#`, allow), so re-adding the identical entry is a no-op — so it is
-    // swallowed. (Until the exit code was fixed this was invisible: the tool returned 0 and the
-    // rejection was lost; now it surfaces, and each of these adds must tolerate its own idempotent
-    // re-run explicitly.)
+    // createRole and addRoleACL are one-shot: each rejects with an "already exists" when re-run
+    // against a role/ACL it created on a previous reconcile. That rejection is the intended terminal
+    // state, so it is swallowed.
     await ignoreExisting(this.ctl("createRole", role));
-    for (const acl of ["publishClientSend", "publishClientReceive", "subscribePattern"]) {
-      // allow (1) this client to send to, receive on, and subscribe under its own subtree.
-      await ignoreExisting(this.ctl("addRoleACL", role, acl, pattern, "allow"));
+    const wanted = wantedAcls(filters);
+    const current = parseRoleAcls(await this.ctl("getRole", role));
+    for (const acl of missingAcls(current, wanted)) {
+      await ignoreExisting(this.ctl("addRoleACL", role, acl.type, acl.topic, "allow"));
+    }
+    // What the consumer no longer asks for — added before it narrowed its topics — is taken away.
+    for (const acl of staleAcls(current, wanted)) {
+      await ignoreMissing(this.ctl("removeRoleACL", role, acl.type, acl.topic));
     }
     // Bind the role only when it is not already bound — addClientRole is the one call whose
     // idempotent re-run cannot be recognised by message (see clientHasRole).
@@ -181,25 +189,31 @@ export class MosquittoClient {
   }
 
   /**
-   * Whether a consumer's client accepts exactly this password and still carries its own role.
-   * Read-only. The password is checked the way the consumer is checked, by an MQTT CONNECT as it,
-   * and the broker's CONNACK code is the answer: 0 accepted, 4 bad credentials, 5 not authorised.
-   * Nothing rides on argv. An unreachable broker rejects (novox/hq issue 120).
+   * Whether a consumer's client accepts exactly this password, still carries its own role, and that
+   * role grants exactly these filters. Read-only. The password is checked the way the consumer is
+   * checked, by an MQTT CONNECT as it, and the broker's CONNACK code is the answer: 0 accepted,
+   * 4 bad credentials, 5 not authorised. Nothing rides on argv. An unreachable broker rejects
+   * (novox/hq issue 120).
    */
-  async holdsClient(username: string, password: string): Promise<boolean> {
+  async holdsClient(username: string, password: string, filters: readonly string[]): Promise<boolean> {
     const code = await mqttConnack(this.conn.host, this.conn.port, username, password);
     if (code === 4 || code === 5) return false;
     if (code !== 0) throw new Error(`mosquitto refused ${username} with CONNACK ${code}`);
     // The role, asked directly: only "not found" means absent. Any other failure to ask rejects,
     // unlike clientHasRole, which reads every failure as "no role".
-    let out: string;
+    let client: string;
+    let role: string;
     try {
-      out = await this.ctl("getClient", username);
+      client = await this.ctl("getClient", username);
+      role = await this.ctl("getRole", username);
     } catch (err) {
       if (/not\s*found|does not exist|no such/i.test(String(err))) return false;
       throw err;
     }
-    return new RegExp(`(^|\\s)${escapeRegExp(username)}\\s+\\(priority`, "m").test(out);
+    if (!new RegExp(`(^|\\s)${escapeRegExp(username)}\\s+\\(priority`, "m").test(client)) return false;
+    const current = parseRoleAcls(role);
+    const wanted = wantedAcls(filters);
+    return missingAcls(current, wanted).length === 0 && staleAcls(current, wanted).length === 0;
   }
 
   /** Remove a client and the per-client role created for it, idempotently. */

modules/mosquitto/module.json

@@ -20,16 +20,19 @@
     "mosquitto.topic.deprovisioned"
   ],
   "serves": {
-    "mqtt-topic": {}
+    "mqtt-topic": {
+      "scheme": "mqtt",
+      "port": 1883
+    }
   },
   "receives": {
-    "mqtt-topic": "/var/lib/mosquitto-module/grants/mesh.json"
+    "mqtt-topic": "${dir:grants}/mesh.json"
   },
   "grants": {
-    "mqtt-topic": "/var/lib/mosquitto-module/grants"
+    "mqtt-topic": "${dir:grants}"
   },
   "own-secrets": {
-    "admin": "/var/lib/mosquitto-module/admin.secret",
+    "admin": "/var/lib/mesh/mosquitto/admin",
     "broker": "/var/lib/mesh/mosquitto/broker"
   },
   "listens": [
@@ -58,26 +61,24 @@
     {
       "id": "state",
       "type": "directory",
-      "path": "/var/lib/mosquitto-module",
-      "mode": "0700"
+      "mode": "0700",
+      "place": "."
     },
     {
-      "id": "grants-dir",
+      "id": "grants",
       "type": "directory",
-      "path": "/var/lib/mosquitto-module/grants",
       "mode": "0700"
     },
     {
       "id": "data",
       "type": "directory",
-      "path": "/services/mosquitto/data",
       "mode": "0700",
       "owner": "1883:1883"
     },
     {
       "id": "server-conf",
       "type": "file",
-      "path": "/var/lib/mosquitto-module/mosquitto.conf",
+      "path": "${dir:state}/mosquitto.conf",
       "mode": "0600",
       "owner": "1883:1883",
       "content": "persistence true\npersistence_location /mosquitto/data\n\nlog_dest stdout\nlog_type warning\nlog_type error\nlog_type notice\n\n# Every client authenticates; identities and their per-topic ACLs are managed\n# at runtime by the dynamic security plugin, whose store the plugin itself owns.\nallow_anonymous false\nplugin /usr/lib/mosquitto_dynamic_security.so\nplugin_opt_config_file /mosquitto/data/dynamic-security.json\n\n# MQTT listener\nlistener 1883\n\n# MQTT-over-WebSockets listener\nlistener 8081\nprotocol websockets\n"
@@ -93,8 +94,8 @@
       "name": "mosquitto-bootstrap",
       "run-once": true,
       "volumes": [
-        "/services/mosquitto/data:/mosquitto/data",
-        "/var/lib/mosquitto-module/admin.secret:/run/secrets/admin:ro"
+        "${dir:data}:/mosquitto/data",
+        "/var/lib/mesh/mosquitto/admin:/run/secrets/admin:ro"
       ],
       "env": {
         "MESH_PROVISION_MQTT": "mosquitto:1883",
@@ -112,15 +113,15 @@
       "id": "server",
       "type": "container",
       "name": "mosquitto",
-      "image": "eclipse-mosquitto@sha256:6f8d8a947c506f8a2290ec65cd4bd2bc7cb4d43fb5f6271f861cb013e2ef9797",
+      "image": "eclipse-mosquitto@sha256:38c0da4f2ef84284d47b3b3eeea1cb3bdeabe81ee10caf0cd5c5ff61ee3ea408",
       "network": "mosquitto",
       "ports": [
         "1883",
         "8081"
       ],
       "volumes": [
-        "/services/mosquitto/data:/mosquitto/data",
-        "/var/lib/mosquitto-module/mosquitto.conf:/mosquitto/config/mosquitto.conf:ro"
+        "${dir:data}:/mosquitto/data",
+        "${dir:state}/mosquitto.conf:/mosquitto/config/mosquitto.conf:ro"
       ]
     },
     {
@@ -130,8 +131,8 @@
       "network": "mosquitto",
       "volumes": [
         "/var/lib/mesh/mosquitto/broker:/run/secrets/broker:ro",
-        "/var/lib/mosquitto-module/grants:/var/lib/mosquitto-module/grants:ro",
-        "/var/lib/mosquitto-module/admin.secret:/run/secrets/admin:ro"
+        "${dir:grants}:/var/lib/mosquitto-module/grants:ro",
+        "/var/lib/mesh/mosquitto/admin:/run/secrets/admin:ro"
       ],
       "env": {
         "MESH_BROKER_FILE": "/run/secrets/broker",

modules/mosquitto/package.json

@@ -1,9 +1,14 @@
 {
   "name": "@novox/module-mosquitto",
   "version": "0.1.0",
-  "description": "mosquitto — provides the mesh mqtt-topic interface. Its admin client, provisioner, tools and events live here (novox/hq ADR 0039).",
+  "description": "mosquitto \u2014 provides the mesh mqtt-topic interface. Its admin client, provisioner, tools and events live here (novox/hq ADR 0039).",
   "type": "module",
   "private": true,
+  "scripts": {
+    "build": "tsc topics.ts client.ts index.ts tools/index.ts provisioner/index.ts bootstrap/index.ts --module NodeNext --moduleResolution NodeNext --target ES2022 --outDir dist",
+    "typecheck": "tsc -p tsconfig.json",
+    "test": "node --test --experimental-strip-types 'test/*.test.ts'"
+  },
   "dependencies": {
     "@novox/mesh-sdk": "^0.1.1"
   },

modules/mosquitto/provisioner/index.ts

@@ -5,7 +5,14 @@
 //
 // The `mqtt-topic` interface: a consumer connects as `as` with the password the mesh minted, and
 // publishes and subscribes under `<as>/#`, isolated from every other consumer by a Dynamic Security
-// role scoped to exactly that subtree.
+// role scoped to exactly that subtree — unless it contributed `topics`, the MQTT topic filters its
+// work needs (a home-automation hub needs the devices' topics); then the role grants exactly those
+// (topics.ts). A list that is not valid topic filters is refused, and the consumer is not created
+// or changed until it is fixed.
+//
+// What a consumer is told (its binding): `at` — the broker's machine — and `port`, the machine port
+// of the MQTT listener (the manifest's `serves`); `as` is its login, and its copy of the password is
+// the pair credential the mesh delivers to it.
 //
 // **The login and password are the mesh's, not the provisioner's (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.
@@ -15,6 +22,7 @@
 import { runProvisioner, type Provision } from "@novox/mesh-sdk/provisioner";
 import { emit } from "@novox/mesh-sdk/events";
 import { MosquittoClient } from "../client.js";
+import { topicFilters } from "../topics.js";
 
 const mosquitto = MosquittoClient.fromEnv();
 
@@ -29,13 +37,20 @@ async function announce(type: string, body: Record<string, string>): Promise<voi
 
 runProvisioner("mqtt-topic", {
   async create(p: Provision): Promise<void> {
-    // The topic subtree is scoped to the consumer's own login, so one cannot read another's topics.
-    const topicPrefix = p.as;
-    await mosquitto.createScopedClient(p.as, p.password, topicPrefix);
+    // By default the consumer's own subtree, so one cannot read another's topics; what it
+    // contributed as `topics` otherwise.
+    const granted = topicFilters(p.values, p.as);
+    if ("problem" in granted) {
+      // Thrown, so the harness logs it and retries: the consumer stays as it was (or absent) until
+      // its contribution is valid, rather than being given a grant it did not ask for.
+      throw new Error(`${p.as}: ${granted.problem}`);
+    }
+    await mosquitto.createScopedClient(p.as, p.password, granted.filters);
     await announce("topic.provisioned", {
       consumer: p.consumer ?? "",
       username: p.as,
-      topicPrefix,
+      topicPrefix: granted.own ? p.as : "",
+      topics: granted.filters.join(" "),
     });
   },
 
@@ -46,6 +61,9 @@ runProvisioner("mqtt-topic", {
   // Asked every minute by the harness: whether the backend still holds this consumer exactly as
   // the mesh gave it, so a login lost behind the provisioner's back is made again (novox/hq issue 120).
   async holds(p: Provision): Promise<boolean> {
-    return mosquitto.holdsClient(p.as, p.password);
+    const granted = topicFilters(p.values, p.as);
+    // An invalid list was never applied; create refuses it again, loudly, on every pass.
+    if ("problem" in granted) return false;
+    return mosquitto.holdsClient(p.as, p.password, granted.filters);
   },
 });

modules/mosquitto/test/topics.test.ts

@@ -0,0 +1,72 @@
+// What a consumer of mqtt-topic is granted (topics.ts): its own subtree unless it contributed
+// `topics`; a contributed list is granted exactly, refused whole when it is not topic filters; and
+// the role is brought to exactly the wanted ACLs — missing ones added, stale ones removed — read from
+// `mosquitto_ctrl dynsec getRole` as eclipse-mosquitto 2.1.2 prints it.
+
+import { test } from "node:test";
+import assert from "node:assert/strict";
+
+import { filterProblem, missingAcls, parseRoleAcls, staleAcls, topicFilters, wantedAcls } from "../topics.ts";
+
+test("a consumer that contributed nothing gets its own subtree", () => {
+  assert.deepEqual(topicFilters({}, "mesh_ace_hass"), { ok: true, filters: ["mesh_ace_hass/#"], own: true });
+  assert.deepEqual(topicFilters(undefined, "x"), { ok: true, filters: ["x/#"], own: true });
+  // Settings merge into every contribution: keys that are not `topics` change nothing.
+  assert.deepEqual(topicFilters({ endpoints: { web: {} } }, "x"), { ok: true, filters: ["x/#"], own: true });
+});
+
+test("a contributed list is granted exactly, duplicates once", () => {
+  assert.deepEqual(topicFilters({ topics: ["#"] }, "x"), { ok: true, filters: ["#"], own: false });
+  assert.deepEqual(topicFilters({ topics: ["stat/+/POWER", "tele/#", "tele/#", "/octoprint/x"] }, "x"), {
+    ok: true,
+    filters: ["stat/+/POWER", "tele/#", "/octoprint/x"],
+    own: false,
+  });
+});
+
+test("a list that is not topic filters is refused whole", () => {
+  for (const topics of [[], "#", [""], ["a/#/b"], ["a#"], ["a/b+"], [42], ["a\u0000b"], {}]) {
+    const out = topicFilters({ topics } as Record<string, unknown>, "x");
+    assert.equal(out.ok, false, JSON.stringify(topics));
+  }
+  assert.equal(filterProblem("+/+/#"), undefined);
+  assert.equal(filterProblem("#"), undefined);
+});
+
+const GET_ROLE = `Warning: You are running mosquitto_ctrl without encryption.
+This means all of the configuration changes you are making are visible on the network, including passwords.
+
+Rolename: u1
+ACLs:     publishClientSend    : allow : # (priority: 0)
+          subscribePattern     : allow : u1/# (priority: 0)
+          publishClientReceive : deny : secret topic/with space (priority: -1)
+`;
+
+test("getRole's ACL lines are read, the warning and headings are not", () => {
+  assert.deepEqual(parseRoleAcls(GET_ROLE), [
+    { type: "publishClientSend", allow: true, topic: "#" },
+    { type: "subscribePattern", allow: true, topic: "u1/#" },
+    { type: "publishClientReceive", allow: false, topic: "secret topic/with space" },
+  ]);
+  assert.deepEqual(parseRoleAcls("Rolename: empty\nACLs:\n"), []);
+});
+
+test("the role is brought to exactly the wanted ACLs", () => {
+  const current = parseRoleAcls(GET_ROLE);
+  const wanted = wantedAcls(["u1/#"]);
+  assert.deepEqual(wanted, [
+    { type: "publishClientSend", allow: true, topic: "u1/#" },
+    { type: "publishClientReceive", allow: true, topic: "u1/#" },
+    { type: "subscribePattern", allow: true, topic: "u1/#" },
+  ]);
+  assert.deepEqual(missingAcls(current, wanted), [
+    { type: "publishClientSend", allow: true, topic: "u1/#" },
+    { type: "publishClientReceive", allow: true, topic: "u1/#" },
+  ]);
+  assert.deepEqual(staleAcls(current, wanted), [
+    { type: "publishClientSend", allow: true, topic: "#" },
+    { type: "publishClientReceive", allow: false, topic: "secret topic/with space" },
+  ]);
+  assert.deepEqual(staleAcls(wanted, wanted), []);
+  assert.deepEqual(missingAcls(wanted, wanted), []);
+});

modules/mosquitto/topics.ts

@@ -0,0 +1,107 @@
+// Which topics a consumer of `mqtt-topic` may use — the one choice a consumer makes about its grant.
+//
+// **By default, its own subtree and nothing else.** A consumer connects as the login the mesh derived
+// (`as`) and may publish, receive and subscribe under `<as>/#` — isolated from every other consumer,
+// which is the point of a per-consumer client (novox/hq ADR 0039/0048).
+//
+// **A consumer whose work IS the shared topic space says so.** Home Assistant discovers devices
+// under `homeassistant/#` and `tasmota/discovery/#` and follows whatever state topics they announce;
+// Node-RED's flows subscribe to the topics devices publish on (`stat/<device>/POWER`, …). Confined
+// to `<as>/#` neither could do its job. So a consumer contributes `topics` to its `mqtt-topic`
+// requirement — a list of MQTT topic filters — and the provisioner grants exactly those, both ways.
+// Because assignment settings merge into every contribution, an operator narrows (or widens) the
+// list per machine with the same key, without editing a manifest.
+//
+// Pure, so it is tested without a broker (test/topics.test.ts).
+
+/** The dynsec ACL types a granted filter carries: send to it, receive from it, subscribe to it. */
+export const GRANTED_ACL_TYPES = ["publishClientSend", "publishClientReceive", "subscribePattern"] as const;
+
+/** One ACL on a role, as `mosquitto_ctrl dynsec getRole` reports it. */
+export interface Acl {
+  type: string;
+  allow: boolean;
+  topic: string;
+}
+
+export type Filters = { ok: true; filters: string[]; own: boolean } | { ok: false; problem: string };
+
+/**
+ * The topic filters a consumer is granted: what it contributed as `topics`, or its own subtree when
+ * it contributed nothing. Refused — never silently narrowed or widened — when the list is not a
+ * list of valid MQTT topic filters: a grant that quietly differs from what was asked is a consumer
+ * that fails somewhere far from the cause.
+ */
+export function topicFilters(values: Readonly<Record<string, unknown>> | undefined, as: string): Filters {
+  const given = values?.topics;
+  if (given === undefined || given === null) {
+    return { ok: true, filters: [`${as}/#`], own: true };
+  }
+  if (!Array.isArray(given) || given.length === 0) {
+    return { ok: false, problem: `topics must be a non-empty list of MQTT topic filters, not ${JSON.stringify(given)}` };
+  }
+  const out: string[] = [];
+  for (const f of given) {
+    if (typeof f !== "string") {
+      return { ok: false, problem: `topics holds ${JSON.stringify(f)}, which is not a topic filter` };
+    }
+    const problem = filterProblem(f);
+    if (problem) return { ok: false, problem: `topic filter ${JSON.stringify(f)}: ${problem}` };
+    if (!out.includes(f)) out.push(f);
+  }
+  return { ok: true, filters: out, own: out.length === 1 && out[0] === `${as}/#` };
+}
+
+/** Why a string is not a valid MQTT topic filter (MQTT 3.1.1 §4.7), or undefined when it is one. */
+export function filterProblem(filter: string): string | undefined {
+  if (filter.length === 0) return "it is empty";
+  if (Buffer.byteLength(filter, "utf8") > 65535) return "it is longer than MQTT allows";
+  if (filter.includes("\u0000")) return "it contains a NUL character";
+  const levels = filter.split("/");
+  for (let i = 0; i < levels.length; i++) {
+    const level = levels[i];
+    if (level.includes("#") && (level !== "#" || i !== levels.length - 1)) {
+      return "'#' must be a whole level, and the last one";
+    }
+    if (level.includes("+") && level !== "+") return "'+' must be a whole level";
+  }
+  return undefined;
+}
+
+/** The ACLs a role must carry to grant these filters: every granted type, allowed, on every filter. */
+export function wantedAcls(filters: readonly string[]): Acl[] {
+  const out: Acl[] = [];
+  for (const topic of filters) {
+    for (const type of GRANTED_ACL_TYPES) out.push({ type, allow: true, topic });
+  }
+  return out;
+}
+
+/**
+ * The ACLs `mosquitto_ctrl dynsec getRole` lists, one per line under its "ACLs:" heading:
+ *   `ACLs:     publishClientSend    : allow : # (priority: 0)`
+ *   `          subscribePattern     : allow : u1/# (priority: 0)`
+ */
+export function parseRoleAcls(output: string): Acl[] {
+  const out: Acl[] = [];
+  const line = /^(?:ACLs:)?\s*([A-Za-z]+)\s*:\s*(allow|deny)\s*:\s*(.*?)\s+\(priority:\s*-?\d+\)\s*$/;
+  for (const raw of output.split(/\r?\n/)) {
+    const m = raw.match(line);
+    if (m) out.push({ type: m[1], allow: m[2] === "allow", topic: m[3] });
+  }
+  return out;
+}
+
+const key = (a: Acl): string => `${a.type}\u0000${a.allow ? "allow" : "deny"}\u0000${a.topic}`;
+
+/** ACLs a role carries that it should not: in `current` and not in `wanted`. */
+export function staleAcls(current: readonly Acl[], wanted: readonly Acl[]): Acl[] {
+  const want = new Set(wanted.map(key));
+  return current.filter((a) => !want.has(key(a)));
+}
+
+/** ACLs a role should carry and does not. */
+export function missingAcls(current: readonly Acl[], wanted: readonly Acl[]): Acl[] {
+  const have = new Set(current.map(key));
+  return wanted.filter((a) => !have.has(key(a)));
+}

modules/mosquitto/tsconfig.json

@@ -8,5 +8,5 @@
     "skipLibCheck": true,
     "noEmit": true
   },
-  "include": ["client.ts", "index.ts", "provisioner/index.ts", "tools/index.ts", "bootstrap/index.ts"]
+  "include": ["topics.ts", "client.ts", "index.ts", "provisioner/index.ts", "tools/index.ts", "bootstrap/index.ts"]
 }