Configurable user cache population in auth middleware

packages/auth/src/cache/user.js

@@ -3,7 +3,27 @@ const { getTenantId, lookupTenantId, getGlobalDB } = require("../tenancy")
 
 const EXPIRY_SECONDS = 3600
 
-exports.getUser = async (userId, tenantId = null) => {
+/**
+ * The default populate user function
+ */
+const populateFromDB = (userId, tenantId) => {
+  return getGlobalDB(tenantId).get(userId)
+}
+
+/**
+ * Get the requested user by id.
+ * Use redis cache to first read the user.
+ * If not present fallback to loading the user directly and re-caching.
+ * @param {*} userId the id of the user to get
+ * @param {*} tenantId the tenant of the user to get
+ * @param {*} loadUser function to provide the user for re-caching. default to couch db
+ * @returns
+ */
+exports.getUser = async (
+  userId,
+  tenantId = null,
+  populateUser = populateFromDB
+) => {
   if (!tenantId) {
     try {
       tenantId = getTenantId()
@@ -15,7 +35,7 @@ exports.getUser = async (userId, tenantId = null) => {
   // try cache
   let user = await client.get(userId)
   if (!user) {
-    user = await getGlobalDB(tenantId).get(userId)
+    user = await populateUser(userId, tenantId)
     client.store(userId, user, EXPIRY_SECONDS)
   }
   if (user && !user.tenantId && tenantId) {

packages/auth/src/middleware/authenticated.js

@@ -21,7 +21,10 @@ function finalise(
  * The tenancy modules should not be used here and it should be assumed that the tenancy context
  * has not yet been populated.
  */
-module.exports = (noAuthPatterns = [], opts = { publicAllowed: false }) => {
+module.exports = (
+  noAuthPatterns = [],
+  opts = { publicAllowed: false, populateUser: null }
+) => {
   const noAuthOptions = noAuthPatterns ? buildMatcherRegex(noAuthPatterns) : []
   return async (ctx, next) => {
     let publicEndpoint = false
@@ -46,7 +49,15 @@ module.exports = (noAuthPatterns = [], opts = { publicAllowed: false }) => {
           error = "No session found"
         } else {
           try {
+            if (opts && opts.populateUser) {
+              user = await getUser(
+                userId,
+                session.tenantId,
+                opts.populateUser(ctx)
+              )
+            } else {
               user = await getUser(userId, session.tenantId)
+            }
             delete user.password
             authenticated = true
           } catch (err) {