Wired up link redirects & tracking (#15418)

refs https://github.com/TryGhost/Team/issues/1910
refs https://github.com/TryGhost/Team/issues/1888

- Uses an in-memory repository for now whilst in development
- Updates the LinkReplacementService to choose the slug
- Exposes a `getSlug` method so we can ensure uniqueness
- Emits the RedirectEvent for use by LinkTracking

ghost/core/core/server/services/link-click-tracking/index.js

@@ -1,5 +1,5 @@
 class LinkTrackingServiceWrapper {
-    init() {
+    async init() {
         if (this.service) {
             // Already done
             return;
@@ -9,9 +9,16 @@ class LinkTrackingServiceWrapper {
         const LinkTrackingService = require('@tryghost/link-tracking');
 
         // Expose the service
-        this.service = new LinkTrackingService();
+        this.service = new LinkTrackingService({
+            linkClickRepository: {
+                async save(linkClick) {
+                    // eslint-disable-next-line no-console
+                    console.log('Saving link click', linkClick);
+                }
+            }
+        });
 
-        return this.service.init();
+        await this.service.init();
     }
 }
 

ghost/core/core/server/services/link-redirection/index.js

@@ -1,3 +1,5 @@
+const urlUtils = require('../../../shared/url-utils');
+
 class LinkRedirectsServiceWrapper {
     async init() {
         if (this.service) {
@@ -8,8 +10,23 @@ class LinkRedirectsServiceWrapper {
         // Wire up all the dependencies
         const {LinkRedirectsService} = require('@tryghost/link-redirects');
 
+        const store = [];
         // Expose the service
-        this.service = new LinkRedirectsService();
+        this.service = new LinkRedirectsService({
+            linkRedirectRepository: {
+                async save(linkRedirect) {
+                    store.push(linkRedirect);
+                },
+                async getByURL(url) {
+                    return store.find((link) => {
+                        return link.from.pathname === url.pathname;
+                    });
+                }
+            },
+            config: {
+                baseURL: new URL(urlUtils.getSiteUrl())
+            }
+        });
     }
 }
 

ghost/link-redirects/lib/LinkRedirectsService.js

@@ -1,21 +1,62 @@
+const crypto = require('crypto');
+const DomainEvents = require('@tryghost/domain-events');
+const RedirectEvent = require('./RedirectEvent');
 const LinkRedirect = require('./LinkRedirect');
 
+/**
+ * @typedef {object} ILinkRedirectRepository
+ * @prop {(url: URL) => Promise<LinkRedirect>} getByURL
+ * @prop {(linkRedirect: LinkRedirect) => Promise<void>} save
+ */
+
 class LinkRedirectsService {
+    /** @type ILinkRedirectRepository */
+    #linkRedirectRepository;
+    /** @type URL */
+    #baseURL;
+
+    /**
+     * @param {object} deps
+     * @param {ILinkRedirectRepository} deps.linkRedirectRepository
+     * @param {object} deps.config
+     * @param {URL} deps.config.baseURL
+     */
+    constructor(deps) {
+        this.#linkRedirectRepository = deps.linkRedirectRepository;
+        if (!deps.config.baseURL.pathname.endsWith('/')) {
+            this.#baseURL = new URL(deps.config.baseURL);
+            this.#baseURL.pathname += '/';
+        } else {
+            this.#baseURL = deps.config.baseURL;
+        }
+        this.handleRequest = this.handleRequest.bind(this);
+    }
+
+    /**
+     * Get a unique slug for a redirect which hasn't already been taken
+     *
+     * @returns {Promise<string>}
+     */
+    async getSlug() {
+        return crypto.randomBytes(4).toString('hex');
+    }
+
     /**
      * @param {URL} to
+     * @param {string} slug
      *
      * @returns {Promise<LinkRedirect>}
      */
-    async addRedirect(to) {
+    async addRedirect(to, slug) {
-        const from = new URL(to);
+        const from = new URL(`r/${slug}`, this.#baseURL);
-
-        from.searchParams.set('redirected', 'true'); // Dummy for skateboard
 
         const link = new LinkRedirect({
             to,
             from
         });
 
+        await this.#linkRedirectRepository.save(link);
+
         return link;
     }
 
@@ -27,7 +68,21 @@ class LinkRedirectsService {
      * @returns {Promise<void>}
      */
     async handleRequest(req, res, next) {
-        return next();
+        const url = new URL(req.originalUrl, this.#baseURL);
+        const link = await this.#linkRedirectRepository.getByURL(url);
+
+        if (!link) {
+            return next();
+        }
+
+        const event = RedirectEvent.create({
+            url,
+            link
+        });
+
+        DomainEvents.dispatch(event);
+
+        return res.redirect(link.to.href);
     }
 }
 

ghost/link-redirects/package.json

@@ -25,6 +25,7 @@
     "sinon": "14.0.0"
   },
   "dependencies": {
-    "bson-objectid": "2.0.3"
+    "bson-objectid": "2.0.3",
+    "@tryghost/domain-events": "0.0.0"
   }
 }

ghost/link-replacement/lib/link-replacement.js

@@ -6,7 +6,8 @@
 
 /**
  * @typedef {object} ILinkRedirectService
- * @prop {(to: URL) => Promise<ILinkRedirect>} addRedirect
+ * @prop {(to: URL, slug: string) => Promise<ILinkRedirect>} addRedirect
+ * @prop {() => Promise<string>} getSlug
  */
 
 /**
@@ -87,8 +88,10 @@ class LinkReplacementService {
             url = this.#attributionService.addPostAttributionTracking(url, post);
         }
 
+        const slug = await this.#linkRedirectService.getSlug();
+
         // 2. Add redirect for link click tracking
-        const redirect = await this.#linkRedirectService.addRedirect(url);
+        const redirect = await this.#linkRedirectService.addRedirect(url, slug);
 
         // 3. Add click tracking by members
         // Note: we can always add the tracking params (even when isSite === false)

ghost/link-replacement/test/link-replacement.test.js

@@ -54,6 +54,9 @@ describe('LinkReplacementService', function () {
         const linkRedirectService = {
             addRedirect: (to) => {
                 return Promise.resolve({to, from: 'https://redirected.service/r/ro0sdD92'});
+            },
+            getSlug: () => {
+                return Promise.resolve('slug');
             }
         };
         const service = new LinkReplacementService({
@@ -120,19 +123,19 @@ describe('LinkReplacementService', function () {
             it('returns the redirected URL with uuid', async function () {
                 const replaced = await service.replaceLink(new URL('http://localhost:2368/dir/path'), {}, {id: 'post_id'});
                 assert.equal(replaced.toString(), 'https://redirected.service/r/ro0sdD92?m=--uuid--');
-                assert(redirectSpy.calledOnceWithExactly(new URL('http://localhost:2368/dir/path?rel=newsletter&attribution_id=post_id')));
+                assert(redirectSpy.calledOnceWithExactly(new URL('http://localhost:2368/dir/path?rel=newsletter&attribution_id=post_id'), 'slug'));
             });
 
             it('does not add attribution for external sites', async function () {
                 const replaced = await service.replaceLink(new URL('http://external.domain/dir/path'), {}, {id: 'post_id'});
                 assert.equal(replaced.toString(), 'https://redirected.service/r/ro0sdD92?m=--uuid--');
-                assert(redirectSpy.calledOnceWithExactly(new URL('http://external.domain/dir/path?rel=newsletter')));
+                assert(redirectSpy.calledOnceWithExactly(new URL('http://external.domain/dir/path?rel=newsletter'), 'slug'));
             });
 
             it('does not add attribution or member tracking if click tracking is disabled', async function () {
                 const replaced = await disabledService.replaceLink(new URL('http://external.domain/dir/path'), {}, {id: 'post_id'});
                 assert.equal(replaced.toString(), 'https://redirected.service/r/ro0sdD92');
-                assert(redirectSpy.calledOnceWithExactly(new URL('http://external.domain/dir/path?rel=newsletter')));
+                assert(redirectSpy.calledOnceWithExactly(new URL('http://external.domain/dir/path?rel=newsletter'), 'slug'));
             });
         });
 
@@ -140,7 +143,7 @@ describe('LinkReplacementService', function () {
             it('Replaces hrefs inside links', async function () {
                 const html = '<a href="http://localhost:2368/dir/path">link</a>';
                 const expected = '<a href="https://redirected.service/r/ro0sdD92?m=%%{uuid}%%">link</a>';
-                
+
                 const replaced = await service.replaceLinks(html, {}, {id: 'post_id'});
                 assert.equal(replaced, expected);
             });
@@ -148,7 +151,7 @@ describe('LinkReplacementService', function () {
             it('Ignores invalid links', async function () {
                 const html = '<a href="%%{unsubscribe_url}%%">link</a>';
                 const expected = '<a href="%%{unsubscribe_url}%%">link</a>';
-                
+
                 const replaced = await service.replaceLinks(html, {}, {id: 'post_id'});
                 assert.equal(replaced, expected);
             });

ghost/link-tracking/lib/LinkClick.js

@@ -0,0 +1,25 @@
+const ObjectID = require('bson-objectid').default;
+
+module.exports = class ClickEvent {
+    /** @type {ObjectID} */
+    event_id;
+    /** @type {ObjectID} */
+    member_id;
+    /** @type {ObjectID} */
+    link_id;
+
+    constructor(data) {
+        if (!data.id) {
+            this.event_id = new ObjectID();
+        }
+
+        if (typeof data.id === 'string') {
+            this.event_id = ObjectID.createFromHexString(data.id);
+        } else {
+            this.event_id = data.id;
+        }
+
+        this.member_id = data.member_id;
+        this.link_id = data.link_id;
+    }
+};

ghost/link-tracking/lib/link-tracking.js

@@ -1,9 +1,28 @@
+const ObjectID = require('bson-objectid').default;
 const DomainEvents = require('@tryghost/domain-events');
 const {RedirectEvent} = require('@tryghost/link-redirects');
+const logging = require('@tryghost/logging');
+const LinkClick = require('./LinkClick');
+
+/**
+ * @typedef {object} ILinkClickRepository
+ * @prop {(event: LinkClick) => Promise<void>} save
+ */
 
 class LinkClickTrackingService {
     #initialised = false;
 
+    /** @type ILinkClickRepository */
+    #linkClickRepository;
+
+    /**
+     * @param {object} deps
+     * @param {ILinkClickRepository} deps.linkClickRepository
+     */
+    constructor(deps) {
+        this.#linkClickRepository = deps.linkClickRepository;
+    }
+
     async init() {
         if (this.#initialised) {
             return;
@@ -13,7 +32,7 @@ class LinkClickTrackingService {
     }
 
     /**
-     * @param {import('@tryghost/link-redirects/LinkRedirect')} redirect
+     * @param {import('@tryghost/link-redirects').LinkRedirect} redirect
      * @param {string} id
      * @return {Promise<URL>}
      */
@@ -24,18 +43,25 @@ class LinkClickTrackingService {
     }
 
     subscribe() {
-        DomainEvents.subscribe(RedirectEvent, (event) => {
+        DomainEvents.subscribe(RedirectEvent, async (event) => {
             const id = event.data.url.searchParams.get('m');
-            if (typeof id !== 'string') {
+            if (!id) {
                 return;
             }
 
-            const clickEvent = {
+            let memberId;
-                member_id: id,
+            try {
+                memberId = ObjectID.createFromHexString(id);
+            } catch (err) {
+                logging.warn(`Invalid member_id "${id}" found during redirect`);
+                return;
+            }
+
+            const click = new LinkClick({
+                member_id: memberId,
                 link_id: event.data.link.link_id
-            };
+            });
-            // eslint-disable-next-line no-console
+            await this.#linkClickRepository.save(click);
-            console.log('Finna store a click event', clickEvent);
         });
     }
 }

ghost/link-tracking/package.json

@@ -24,7 +24,7 @@
     "sinon": "14.0.0"
   },
   "dependencies": {
-    "@tryghost/domain-events": "^0.1.14",
+    "@tryghost/domain-events": "0.0.0",
     "@tryghost/link-redirects": "0.0.0"
   }
 }

yarn.lock

@@ -3489,11 +3489,6 @@
     "@tryghost/root-utils" "^0.3.16"
     debug "^4.3.1"
 
-"@tryghost/domain-events@^0.1.14":
-  version "0.1.14"
-  resolved "https://registry.yarnpkg.com/@tryghost/domain-events/-/domain-events-0.1.14.tgz#a0206b21981d8e3337dfc0ed56df182d6e7188b3"
-  integrity sha512-SoJMvrwBXFDciQwjobpuZae0AQ/pVB+RgSj+QEuKNqg6V6CAhNlLrI1rAhkHtXkuKaLDDzH8tKWQEeeApXdBng==
-
 "@tryghost/elasticsearch@^3.0.3":
   version "3.0.3"
   resolved "https://registry.yarnpkg.com/@tryghost/elasticsearch/-/elasticsearch-3.0.3.tgz#6651298989f38bbe30777ab122d56a43f719d2c2"