DC-144: DashCaddy-side groups + resources model/routes with cascade delete + tests

dashcaddy-api/src/security/network-groups.js

@@ -0,0 +1,374 @@
+/**
+ * Network groups service — DC-144.
+ *
+ * DashCaddy-side groups (spec §2): a group is just an id/name used in
+ * person.groups[] and in access grants. Groups are a UI-side concept ONLY —
+ * they NEVER map to Tailscale ACL groups (free TS plans cap groups at 3;
+ * compiled ACLs reference users directly, see DC-148). Group ids are
+ * DashCaddy-local slug strings and are validated as such.
+ *
+ * Because groups are not a separate entity store, the set of groups is
+ * DERIVED: the union of every id appearing in person.groups[] plus a
+ * display-names map persisted at data/network-groups.json
+ * ({ groups: [{ id, name }] }). 'Admin' is the well-known group (matches
+ * the people-store bootstrap admin) and can never be renamed or deleted.
+ *
+ * renameGroup(fromId, { id: toId, name }) re-points every reference —
+ * person.groups[] entries AND access grants with principal
+ * { type: 'group', id: fromId } — by orchestrating the people store and
+ * the access store through their public APIs (listPeople/updatePerson,
+ * getAccessMap/saveAccessMap). deleteGroup(id) cascades the same way:
+ * the group is removed from every person.groups[] entry and every grant
+ * referencing it is dropped.
+ *
+ * Storage: same atomic JSON pattern as the other network stores
+ * (fsync'd tmp+rename via the shared atomic-write util).
+ */
+
+'use strict';
+
+const path = require('path');
+const fs = require('fs');
+const platformPaths = require('../../platform-paths');
+const { atomicWriteJSON } = require('../utils/atomic-write');
+
+const ADMIN_GROUP = 'Admin'; // must match network-people-store.ADMIN_GROUP
+const SLUG_RE = /^[a-z0-9-]+$/;
+
+/**
+ * Operational error thrown by the groups service. Carries an HTTP
+ * statusCode so route error handlers can map it without instanceof
+ * coupling (same convention as LastAdminError).
+ */
+class GroupError extends Error {
+  constructor(message, statusCode = 400, code = 'DC_GROUP_ERROR') {
+    super(message);
+    this.name = 'GroupError';
+    this.statusCode = statusCode;
+    this.code = code;
+    this.isOperational = true;
+  }
+}
+
+function _readJSON(filePath, fallback) {
+  try {
+    const raw = fs.readFileSync(filePath, 'utf8');
+    return JSON.parse(raw);
+  } catch (err) {
+    if (err && err.code === 'ENOENT') return fallback;
+    // Corrupt file: quarantine best-effort, restart from fallback.
+    try {
+      fs.renameSync(filePath, `${filePath}.corrupt-${Date.now()}`);
+    } catch (_) { /* best-effort */ }
+    return fallback;
+  }
+}
+
+function _normalizeNames(data) {
+  const out = new Map();
+  if (data && Array.isArray(data.groups)) {
+    for (const g of data.groups) {
+      if (g && typeof g === 'object' && typeof g.id === 'string' && g.id.length > 0) {
+        out.set(g.id, typeof g.name === 'string' && g.name.length > 0 ? g.name : g.id);
+      }
+    }
+  }
+  return out;
+}
+
+function createGroupsService(opts = {}) {
+  const candidates = [
+    opts.dataDir,
+    opts.platformPaths && opts.platformPaths.dataDir,
+    platformPaths && platformPaths.dataDir,
+  ];
+  const dataDir = candidates.find(c => typeof c === 'string' && c.length > 0)
+    || require('os').tmpdir(); // eslint-disable-line global-require
+  const log = opts.log || { info() {}, warn() {}, error() {} };
+  const peopleStore = opts.peopleStore;
+  const accessStore = opts.accessStore;
+
+  if (!peopleStore || typeof peopleStore.listPeople !== 'function') {
+    throw new Error('createGroupsService requires a peopleStore');
+  }
+  if (!accessStore || typeof accessStore.getAccessMap !== 'function') {
+    throw new Error('createGroupsService requires an accessStore');
+  }
+
+  const file = path.join(dataDir, 'network-groups.json');
+
+  // Serialized mutation mutex — renames/deletes touch multiple stores and
+  // must not interleave with each other.
+  let _mutex = Promise.resolve();
+  function _enqueue(fn) {
+    const next = _mutex.then(fn, fn);
+    _mutex = next.catch(() => {});
+    return next;
+  }
+
+  function _loadNames() {
+    return _normalizeNames(_readJSON(file, { groups: [] }));
+  }
+
+  function _saveNames(names) {
+    const groups = [...names.entries()]
+      .map(([id, name]) => ({ id, name }))
+      .sort((a, b) => a.id.localeCompare(b.id));
+    atomicWriteJSON(file, { groups });
+  }
+
+  /**
+   * Derived group set: union of ids in person.groups[], ids in the names
+   * map, ids referenced by group grants, plus the well-known 'Admin'.
+   * Returns Map<id, {name, memberCount}> sorted by id.
+   */
+  async function _derived() {
+    const names = _loadNames();
+    const people = await peopleStore.listPeople();
+    const map = new Map(); // id -> memberCount
+    map.set(ADMIN_GROUP, 0);
+    for (const p of people) {
+      for (const gid of Array.isArray(p.groups) ? p.groups : []) {
+        if (typeof gid !== 'string' || gid.length === 0) continue;
+        map.set(gid, (map.get(gid) || 0) + 1);
+      }
+    }
+    for (const id of names.keys()) {
+      if (!map.has(id)) map.set(id, 0);
+    }
+    const access = await accessStore.getAccessMap();
+    for (const g of access.grants) {
+      if (g.principal && g.principal.type === 'group' && !map.has(g.principal.id)) {
+        map.set(g.principal.id, 0);
+      }
+    }
+    const out = new Map();
+    for (const id of [...map.keys()].sort((a, b) => a.localeCompare(b))) {
+      out.set(id, { id, name: names.get(id) || id, memberCount: map.get(id) });
+    }
+    return out;
+  }
+
+  /**
+   * List all groups (derived), sorted by id: [{ id, name, memberCount }].
+   */
+  function listGroups() {
+    return _enqueue(async () => [...(await _derived()).values()]);
+  }
+
+  /**
+   * One group by id, or null.
+   */
+  async function getGroup(id) {
+    const all = await listGroups();
+    return all.find(g => g.id === id) || null;
+  }
+
+  /**
+   * Create a group ({ id, name }). Validation: id must be a DashCaddy-local
+   * slug (/^[a-z0-9-]+$/, lowercase — the well-known 'Admin' id is rejected
+   * as a duplicate of the always-present group), unique across the derived
+   * set; name is a non-empty string (≤ 200 chars). The group becomes
+   * visible immediately even with zero members because its id is persisted
+   * in the names map.
+   */
+  function createGroup(input = {}) {
+    return _enqueue(async () => {
+      const { id, name } = input;
+      // Well-known group is checked BEFORE the slug gate — its id ('Admin')
+      // is intentionally not a lowercase slug; creating it means duplicate.
+      if (id === ADMIN_GROUP) {
+        throw new GroupError(`group '${ADMIN_GROUP}' already exists (well-known group)`, 409, 'DC_GROUP_EXISTS');
+      }
+      if (typeof id !== 'string' || !SLUG_RE.test(id)) {
+        throw new GroupError(
+          `group id must match ${SLUG_RE.toString()} (DashCaddy-local slug; never a Tailscale ACL group)`,
+          400, 'DC_GROUP_INVALID_ID');
+      }
+      if (typeof name !== 'string' || name.trim().length === 0 || name.length > 200) {
+        throw new GroupError('group name is required (1-200 chars)', 400, 'DC_GROUP_INVALID_NAME');
+      }
+      const derived = await _derived();
+      if (derived.has(id)) {
+        throw new GroupError(`group '${id}' already exists`, 409, 'DC_GROUP_EXISTS');
+      }
+      const names = _loadNames();
+      names.set(id, name.trim());
+      _saveNames(names);
+      log.info && log.info('network-groups', 'group created', { id });
+      return { id, name: name.trim(), memberCount: 0 };
+    });
+  }
+
+  /**
+   * Re-point every reference from one group id to another: each
+   * person.groups[] entry and each access grant with principal
+   * { type: 'group', id: fromId } — driven through the stores' public
+   * APIs. Returns { peopleUpdated, grantsUpdated }.
+   */
+  async function _repointReferences(fromId, toId) {
+    let peopleUpdated = 0;
+    let grantsUpdated = 0;
+    // Cascade: re-point person.groups[] …
+    const people = await peopleStore.listPeople();
+    for (const p of people) {
+      if ((p.groups || []).includes(fromId)) {
+        await peopleStore.updatePerson(p.id, {
+          groups: p.groups.map(g => (g === fromId ? toId : g)),
+        });
+        peopleUpdated += 1;
+      }
+    }
+    // … and group-principal grant references.
+    const access = await accessStore.getAccessMap();
+    const grants = access.grants.map(g => (
+      g.principal && g.principal.type === 'group' && g.principal.id === fromId
+        ? { ...g, principal: { type: 'group', id: toId } }
+        : g
+    ));
+    if (grants.some((g, i) => g !== access.grants[i])) {
+      const res = await accessStore.saveAccessMap({ grants });
+      if (!res.ok) {
+        throw new GroupError(res.reason || 'access map rejected the rename cascade', 500, 'DC_GROUP_CASCADE_FAILED');
+      }
+      grantsUpdated = access.grants.filter(
+        g => g.principal && g.principal.type === 'group' && g.principal.id === fromId
+      ).length;
+    }
+    return { peopleUpdated, grantsUpdated };
+  }
+
+  /**
+   * Validate the rename patch for a group that exists in `derived`.
+   * Returns the resolved { toId, newName } or throws GroupError.
+   */
+  function _validateRenamePatch(fromId, patch, derived) {
+    const toId = patch.id !== undefined ? patch.id : fromId;
+    const newName = patch.name !== undefined ? patch.name : null;
+    if (toId !== fromId) {
+      if (toId === ADMIN_GROUP) {
+        throw new GroupError(`group id '${ADMIN_GROUP}' is reserved`, 409, 'DC_GROUP_PROTECTED');
+      }
+      if (typeof toId !== 'string' || !SLUG_RE.test(toId)) {
+        throw new GroupError(
+          `group id must match ${SLUG_RE.toString()} (DashCaddy-local slug; never a Tailscale ACL group)`,
+          400, 'DC_GROUP_INVALID_ID');
+      }
+      if (derived.has(toId)) {
+        throw new GroupError(`group '${toId}' already exists`, 409, 'DC_GROUP_EXISTS');
+      }
+    }
+    if (newName !== null
+      && (typeof newName !== 'string' || newName.trim().length === 0 || newName.length > 200)) {
+      throw new GroupError('group name must be 1-200 chars', 400, 'DC_GROUP_INVALID_NAME');
+    }
+    return { toId, newName };
+  }
+
+  /**
+   * Rename a group. patch: { id?: newId, name?: newName }.
+   *
+   * - 'Admin' is well-known: rename refused (409).
+   * - Changing the id re-points EVERY reference: each person.groups[] entry
+   *   and each access grant with principal { type:'group', id: fromId }
+   *   (via the stores' public APIs — peopleStore.updatePerson,
+   *   accessStore.saveAccessMap).
+   * - Changing only the display name touches the names map alone.
+   * Returns the updated group { id, name, memberCount }.
+   */
+  function renameGroup(fromId, patch = {}) {
+    return _enqueue(async () => {
+      if (fromId === ADMIN_GROUP) {
+        throw new GroupError(`group '${ADMIN_GROUP}' is well-known and cannot be renamed`, 409, 'DC_GROUP_PROTECTED');
+      }
+      const derived = await _derived();
+      if (!derived.has(fromId)) {
+        throw new GroupError(`group '${fromId}' not found`, 404, 'DC_GROUP_NOT_FOUND');
+      }
+      const { toId, newName } = _validateRenamePatch(fromId, patch, derived);
+
+      const memberCount = derived.get(fromId).memberCount;
+      const refs = toId !== fromId
+        ? await _repointReferences(fromId, toId)
+        : { peopleUpdated: 0, grantsUpdated: 0 };
+
+      // Names map: move/rename the entry (create one if the group only
+      // ever existed implicitly via person.groups[]).
+      const names = _loadNames();
+      names.delete(fromId);
+      names.set(toId, newName !== null ? newName.trim() : (names.get(toId) || toId));
+      _saveNames(names);
+
+      log.info && log.info('network-groups', 'group renamed', {
+        fromId, toId, ...refs,
+      });
+      return { id: toId, name: names.get(toId), memberCount, ...refs };
+    });
+  }
+
+  /**
+   * Delete a group and cascade: REMOVE the id from every person.groups[]
+   * entry and DROP every access grant whose principal is
+   * { type: 'group', id } — one orchestrating function driving the stores'
+   * public APIs. 'Admin' is protected (409). Returns
+   * { deleted: true, id, removedFromPeople, removedGrants }.
+   */
+  function deleteGroup(id) {
+    return _enqueue(async () => {
+      if (id === ADMIN_GROUP) {
+        throw new GroupError(`group '${ADMIN_GROUP}' is well-known and cannot be deleted`, 409, 'DC_GROUP_PROTECTED');
+      }
+      const derived = await _derived();
+      if (!derived.has(id)) {
+        throw new GroupError(`group '${id}' not found`, 404, 'DC_GROUP_NOT_FOUND');
+      }
+
+      let removedFromPeople = 0;
+      let removedGrants = 0;
+
+      // Cascade 1: strip the group from every person.groups[].
+      const people = await peopleStore.listPeople();
+      for (const p of people) {
+        if ((p.groups || []).includes(id)) {
+          const next = p.groups.filter(g => g !== id);
+          await peopleStore.updatePerson(p.id, { groups: next });
+          removedFromPeople += 1;
+        }
+      }
+
+      // Cascade 2: drop every group grant referencing it.
+      const access = await accessStore.getAccessMap();
+      const kept = [];
+      for (const g of access.grants) {
+        if (g.principal && g.principal.type === 'group' && g.principal.id === id) {
+          removedGrants += 1;
+        } else {
+          kept.push(g);
+        }
+      }
+      if (removedGrants > 0) {
+        const res = await accessStore.saveAccessMap({ grants: kept });
+        if (!res.ok) throw new GroupError(res.reason || 'access map rejected the delete cascade', 500, 'DC_GROUP_CASCADE_FAILED');
+      }
+
+      // Finally remove the names-map entry (if any).
+      const names = _loadNames();
+      names.delete(id);
+      _saveNames(names);
+
+      log.info && log.info('network-groups', 'group deleted', { id, removedFromPeople, removedGrants });
+      return { deleted: true, id, removedFromPeople, removedGrants };
+    });
+  }
+
+  return {
+    listGroups,
+    getGroup,
+    createGroup,
+    renameGroup,
+    deleteGroup,
+    ADMIN_GROUP,
+  };
+}
+
+module.exports = { createGroupsService, GroupError, ADMIN_GROUP };