Added new member limit & removed old

refs: https://github.com/TryGhost/Team/issues/510

- The current member limit was implemented as a member-specific concept
- The new limit service is much more generic, here we are swapping old for new
- The updated concept here is blocking all publishing, not just email sending, when a site is over its member limit
- To determine that we are publishing a post, we must be in the model layer. The code has been moved to the permissible function which makes sense as this is a permissions error that we are throwing
- I've left the extra check for email retries in, in case there is some loophole here (but we may wish to change it)

core/server/api/canary/posts.js

@@ -3,7 +3,6 @@ const {i18n} = require('../../lib/common');
 const errors = require('@tryghost/errors');
 const urlUtils = require('../../../shared/url-utils');
 const {mega} = require('../../services/mega');
-const membersService = require('../../services/members');
 const allowedIncludes = ['tags', 'authors', 'authors.roles', 'email'];
 const unsafeAttrs = ['status', 'authors', 'visibility'];
 
@@ -154,11 +153,6 @@ module.exports = {
             unsafeAttrs: unsafeAttrs
         },
         async query(frame) {
-            /**Check host limits for members when send email is true**/
-            if ((frame.options.email_recipient_filter && frame.options.email_recipient_filter !== 'none') || frame.options.send_email_when_published) {
-                await membersService.checkHostLimit();
-            }
-
             let model;
             if (!frame.options.email_recipient_filter && frame.options.send_email_when_published) {
                 await models.Base.transaction(async (transacting) => {

core/server/api/v3/posts.js

@@ -3,7 +3,6 @@ const {i18n} = require('../../lib/common');
 const errors = require('@tryghost/errors');
 const urlUtils = require('../../../shared/url-utils');
 const {mega} = require('../../services/mega');
-const membersService = require('../../services/members');
 const allowedIncludes = ['tags', 'authors', 'authors.roles', 'email'];
 const unsafeAttrs = ['status', 'authors', 'visibility'];
 
@@ -154,11 +153,6 @@ module.exports = {
             unsafeAttrs: unsafeAttrs
         },
         async query(frame) {
-            /**Check host limits for members when send email is true**/
-            if ((frame.options.email_recipient_filter && frame.options.email_recipient_filter !== 'none') || frame.options.send_email_when_published) {
-                await membersService.checkHostLimit();
-            }
-
             let model;
             if (!frame.options.email_recipient_filter && frame.options.send_email_when_published) {
                 await models.Base.transaction(async (transacting) => {

core/server/models/post.js

@@ -10,6 +10,7 @@ const htmlToPlaintext = require('../../shared/html-to-plaintext');
 const ghostBookshelf = require('./base');
 const config = require('../../shared/config');
 const settingsCache = require('../services/settings/cache');
+const limitService = require('../services/limits');
 const mobiledocLib = require('../lib/mobiledoc');
 const relations = require('./relations');
 const urlUtils = require('../../shared/url-utils');
@@ -1016,7 +1017,7 @@ Post = ghostBookshelf.Model.extend({
     },
 
     // NOTE: the `authors` extension is the parent of the post model. It also has a permissible function.
-    permissible: function permissible(postModel, action, context, unsafeAttrs, loadedPermissions, hasUserPermission, hasApiKeyPermission) {
+    permissible: async function permissible(postModel, action, context, unsafeAttrs, loadedPermissions, hasUserPermission, hasApiKeyPermission) {
         let isContributor;
         let isOwner;
         let isAdmin;
@@ -1048,6 +1049,13 @@ Post = ghostBookshelf.Model.extend({
         isAdd = (action === 'add');
         isDestroy = (action === 'destroy');
 
+        if (limitService.isLimited('members')) {
+            // You can't publish a post if you're over your member limit
+            if ((isEdit && isChanging('status') && isDraft()) || (isAdd && isPublished())) {
+                await limitService.errorIfIsOverLimit('members');
+            }
+        }
+
         if (isContributor && isEdit) {
             // Only allow contributor edit if status is changing, and the post is a draft post
             hasUserPermission = !isChanging('status') && isDraft();

core/server/services/mega/mega.js

@@ -9,6 +9,7 @@ const {events, i18n} = require('../../lib/common');
 const logging = require('../../../shared/logging');
 const settingsCache = require('../settings/cache');
 const membersService = require('../members');
+const limitService = require('../limits');
 const bulkEmailService = require('../bulk-email');
 const jobsService = require('../jobs');
 const db = require('../../data/db');
@@ -253,7 +254,9 @@ async function sendEmailJob({emailModel, options}) {
     try {
         // Check host limit for allowed member count and throw error if over limit
         // - do this even if it's a retry so that there's no way around the limit
-        await membersService.checkHostLimit();
+        if (limitService.isLimited('members')) {
+            await limitService.errorIfIsOverLimit('members');
+        }
 
         // Create email batch and recipient rows unless this is a retry and they already exist
         const existingBatchCount = await emailModel.related('emailBatches').count('id');

core/server/services/members/index.js

@@ -62,8 +62,6 @@ events.on('settings.edited', function updateSettingFromModel(settingModel) {
 const membersService = {
     contentGating: require('./content-gating'),
 
-    checkHostLimit: require('./limit'),
-
     config: membersConfig,
 
     get api() {

core/server/services/members/limit.js

@@ -1,29 +0,0 @@
-const config = require('../../../shared/config');
-const models = require('../../models');
-const errors = require('@tryghost/errors');
-
-// Get total members direct from DB
-async function getTotalMembers() {
-    return models.Member.count('id');
-}
-
-module.exports = async () => {
-    const membersHostLimit = config.get('hostSettings:limits:members');
-    if (membersHostLimit) {
-        const allowedMembersLimit = membersHostLimit.max;
-        const hostUpgradeLink = config.get('hostSettings:limits').upgrade_url;
-
-        const totalMembers = await getTotalMembers();
-
-        if (totalMembers > allowedMembersLimit) {
-            throw new errors.HostLimitError({
-                message: `Your current plan allows you to have up to ${allowedMembersLimit} members, but you currently have ${totalMembers} members`,
-                help: hostUpgradeLink,
-                errorDetails: {
-                    limit: allowedMembersLimit,
-                    total: totalMembers
-                }
-            });
-        }
-    }
-};