Added support for eu Mailgun domain (#73)

closes: https://github.com/TryGhost/Ghost/issues/14640

- eu mailgun domains have a different structure. 
- we weren't accounting for this when fetching the next page of results, meaning that email stats didn't work on EU domains

ghost/email-analytics-provider-mailgun/lib/provider-mailgun.js

@@ -109,8 +109,9 @@ class EmailAnalyticsProviderMailgun {
                 break pagesLoop;
             }
 
-            debug(`_fetchPages: starting fetching next page ${page.paging.next.replace('https://api.mailgun.net/v3', '')}`);
+            const nextPageUrl = page.paging.next.replace(/https:\/\/api\.(eu\.)?mailgun\.net\/v3/, '');
-            page = await mailgun.get(page.paging.next.replace('https://api.mailgun.net/v3', ''));
+            debug(`_fetchPages: starting fetching next page ${nextPageUrl}`);
+            page = await mailgun.get(nextPageUrl);
             events = page && page.items && page.items.map(this.normalizeEvent) || [];
             debug(`_fetchPages: finished fetching next page with ${events.length} events`);
         }

ghost/email-analytics-provider-mailgun/test/fixtures/all-1-eu.json

@@ -0,0 +1,64 @@
+{
+  "items": [
+    {
+      "event": "delivered",
+      "recipient": "recipient1@gmail.com",
+      "user-variables": {
+        "email-id": "5fbe5d9607bdfa3765dc3819"
+      },
+      "message": {
+        "headers": {
+          "message-id": "0201125133533.1.C55897076DBD42F2@domain.com"
+        }
+      },
+      "timestamp": 1606399301.266528
+    },
+    {
+      "event": "failed",
+      "severity": "temporary",
+      "recipient": "recipient2@gmail.com",
+      "user-variables": {
+        "email-id": "5fbe5d9607bdfa3765dc3819"
+      },
+      "message": {
+        "headers": {
+          "message-id": "0201125133533.1.C55897076DBD42F2@domain.com"
+        }
+      },
+      "timestamp": 1606399301.266528
+    },
+    {
+      "event": "failed",
+      "severity": "permanent",
+      "recipient": "recipient3@gmail.com",
+      "user-variables": {
+        "email-id": "5fbe5d9607bdfa3765dc3819"
+      },
+      "message": {
+        "headers": {
+          "message-id": "0201125133533.1.C55897076DBD42F2@domain.com"
+        }
+      },
+      "timestamp": 1606399301.266528
+    },
+    {
+      "event": "unsubscribed",
+      "recipient": "recipient4@gmail.com",
+      "user-variables": {
+        "email-id": "5fbe5d9607bdfa3765dc3819"
+      },
+      "message": {
+        "headers": {
+          "message-id": "0201125133533.1.C55897076DBD42F2@domain.com"
+        }
+      },
+      "timestamp": 1606399301.266528
+    }
+  ],
+  "paging": {
+      "previous": "https://api.eu.mailgun.net/v3/domain.com/events/all-1-previous",
+      "first": "https://api.eu.mailgun.net/v3/domain.com/events/all-1-first",
+      "last": "https://api.eu.mailgun.net/v3/domain.com/events/all-1-last",
+      "next": "https://api.eu.mailgun.net/v3/domain.com/events/all-1-next"
+  }
+}

ghost/email-analytics-provider-mailgun/test/fixtures/all-2-eu.json

@@ -0,0 +1,37 @@
+{
+  "items": [
+    {
+      "event": "delivered",
+      "recipient": "recipient5@gmail.com",
+      "user-variables": {
+        "email-id": "5fbe5d9607bdfa3765dc3819"
+      },
+      "message": {
+        "headers": {
+          "message-id": "0201125133533.1.C55897076DBD42F2@domain.com"
+        }
+      },
+      "timestamp": 1606399301.266528
+    },
+    {
+      "event": "failed",
+      "severity": "temporary",
+      "recipient": "recipient6@gmail.com",
+      "user-variables": {
+        "email-id": "5fbe5d9607bdfa3765dc3819"
+      },
+      "message": {
+        "headers": {
+          "message-id": "0201125133533.1.C55897076DBD42F2@domain.com"
+        }
+      },
+      "timestamp": 1606399301.266528
+    }
+  ],
+  "paging": {
+      "previous": "https://api.eu.mailgun.net/v3/domain.com/events/all-2-previous",
+      "first": "https://api.eu.mailgun.net/v3/domain.com/events/all-2-first",
+      "last": "https://api.eu.mailgun.net/v3/domain.com/events/all-2-last",
+      "next": "https://api.eu.mailgun.net/v3/domain.com/events/all-2-next"
+  }
+}

ghost/email-analytics-provider-mailgun/test/provider-mailgun.test.js

@@ -158,6 +158,51 @@ describe('EmailAnalyticsProviderMailgun', function () {
             batchHandler.callCount.should.eql(2); // one per page
         });
 
+        it('supports EU Mailgun domain', async function () {
+            const configStub = sinon.stub(config, 'get');
+            configStub.withArgs('bulkEmail').returns({
+                mailgun: {
+                    apiKey: 'apiKey',
+                    domain: 'domain.com',
+                    baseUrl: 'https://api.eu.mailgun.net/v3'
+                }
+            });
+
+            const firstPageMock = nock('https://api.eu.mailgun.net')
+                .get('/v3/domain.com/events')
+                .query({
+                    event: 'delivered OR opened OR failed OR unsubscribed OR complained',
+                    limit: 300,
+                    tags: 'bulk-email'
+                })
+                .replyWithFile(200, `${__dirname}/fixtures/all-1-eu.json`, {
+                    'Content-Type': 'application/json'
+                });
+
+            const secondPageMock = nock('https://api.eu.mailgun.net')
+                .get('/v3/domain.com/events/all-1-next')
+                .replyWithFile(200, `${__dirname}/fixtures/all-2-eu.json`, {
+                    'Content-Type': 'application/json'
+                });
+
+            // requests continue until an empty items set is returned
+            nock('https://api.eu.mailgun.net')
+                .get('/v3/domain.com/events/all-2-next')
+                .reply(200, {'Content-Type': 'application/json'}, {
+                    items: []
+                });
+
+            const mailgunProvider = new EmailAnalyticsProviderMailgun({config, settings});
+
+            const batchHandler = sinon.spy();
+
+            await mailgunProvider.fetchAll(batchHandler);
+
+            firstPageMock.isDone().should.be.true();
+            secondPageMock.isDone().should.be.true();
+            batchHandler.callCount.should.eql(2); // one per page
+        });
+
         it('uses custom tags when supplied', async function () {
             const configStub = sinon.stub(config, 'get');
             configStub.withArgs('bulkEmail').returns({
@@ -253,6 +298,54 @@ describe('EmailAnalyticsProviderMailgun', function () {
             batchHandler.callCount.should.eql(2); // one per page
         });
 
+        it('supports EU Mailgun domain', async function () {
+            const configStub = sinon.stub(config, 'get');
+            configStub.withArgs('bulkEmail').returns({
+                mailgun: {
+                    apiKey: 'apiKey',
+                    domain: 'domain.com',
+                    baseUrl: 'https://api.eu.mailgun.net/v3'
+                }
+            });
+
+            const firstPageMock = nock('https://api.eu.mailgun.net')
+                .get('/v3/domain.com/events')
+                .query({
+                    event: 'delivered OR opened OR failed OR unsubscribed OR complained',
+                    limit: 300,
+                    tags: 'bulk-email',
+                    begin: 'Thu, 25 Feb 2021 11:30:00 GMT', // latest minus threshold
+                    ascending: 'yes'
+                })
+                .replyWithFile(200, `${__dirname}/fixtures/all-1-eu.json`, {
+                    'Content-Type': 'application/json'
+                });
+
+            const secondPageMock = nock('https://api.eu.mailgun.net')
+                .get('/v3/domain.com/events/all-1-next')
+                .replyWithFile(200, `${__dirname}/fixtures/all-2-eu.json`, {
+                    'Content-Type': 'application/json'
+                });
+
+            // requests continue until an empty items set is returned
+            nock('https://api.eu.mailgun.net')
+                .get('/v3/domain.com/events/all-2-next')
+                .reply(200, {'Content-Type': 'application/json'}, {
+                    items: []
+                });
+
+            const mailgunProvider = new EmailAnalyticsProviderMailgun({config, settings});
+
+            const batchHandler = sinon.spy();
+
+            const latestTimestamp = new Date('Thu Feb 25 2021 12:00:00 GMT+0000');
+            await mailgunProvider.fetchLatest(latestTimestamp, batchHandler);
+
+            firstPageMock.isDone().should.be.true();
+            secondPageMock.isDone().should.be.true();
+            batchHandler.callCount.should.eql(2); // one per page
+        });
+
         it('uses custom tags when supplied', async function () {
             const configStub = sinon.stub(config, 'get');
             configStub.withArgs('bulkEmail').returns({