Merge pull request #2421 from caprover/agent/add-legacy-service-dns-alias-v2

Preserve legacy DNS names for new app services

src/docker/DockerApi.ts

@@ -65,6 +65,40 @@ export abstract class IDockerUpdateOrders {
 }
 export type IDockerUpdateOrder = 'auto' | 'stopFirst' | 'startFirst'
 
+export function getLegacyServiceDnsAlias(
+    serviceName: string,
+    namespace: string | undefined,
+    isLegacyAppName: boolean
+) {
+    if (!namespace || isLegacyAppName) {
+        return undefined
+    }
+
+    return `srv-${namespace}--${serviceName}`
+}
+
+export interface IServiceNetworkAttachment {
+    Target: string
+    Aliases?: string[]
+}
+
+export function getServiceNetworkAttachments(
+    networks: string[],
+    legacyDnsAlias: string | undefined
+) {
+    return networks.map((network) => {
+        const attachment: IServiceNetworkAttachment = {
+            Target: network,
+        }
+
+        if (legacyDnsAlias) {
+            attachment.Aliases = [legacyDnsAlias]
+        }
+
+        return attachment
+    })
+}
+
 export interface CreateContainerParams {
     containerName?: string
     imageName: string
@@ -1454,11 +1488,25 @@ class DockerApi {
                 }
 
                 if (networks) {
-                    updatedData.TaskTemplate.Networks = []
-                    for (let i = 0; i < networks.length; i++) {
-                        updatedData.TaskTemplate.Networks.push({
-                            Target: networks[i],
-                        })
+                    if (appObject) {
+                        const legacyDnsAlias = getLegacyServiceDnsAlias(
+                            serviceName,
+                            namespace,
+                            !!appObject.isLegacyAppName
+                        )
+
+                        updatedData.TaskTemplate.Networks =
+                            getServiceNetworkAttachments(
+                                networks,
+                                legacyDnsAlias
+                            )
+                    } else {
+                        updatedData.TaskTemplate.Networks = []
+                        for (let i = 0; i < networks.length; i++) {
+                            updatedData.TaskTemplate.Networks.push({
+                                Target: networks[i],
+                            })
+                        }
                     }
                 }
 

tests/ServiceNamingMigration.test.ts

@@ -3,6 +3,10 @@ import AppsDataStore, {
     isNameAllowed,
 } from '../src/datastore/AppsDataStore'
 import { runDataStoreMigrations } from '../src/datastore/DataStore'
+import {
+    getLegacyServiceDnsAlias,
+    getServiceNetworkAttachments,
+} from '../src/docker/DockerApi'
 import ServiceManager from '../src/user/ServiceManager'
 
 function createConfigStore(initialData: { [key: string]: any }) {
@@ -88,6 +92,49 @@ describe('service and volume naming migration', () => {
         expect(failedVolumes).toEqual(['data'])
     })
 
+    test('adds the legacy DNS alias to every network for a new app', () => {
+        const alias = getLegacyServiceDnsAlias(
+            'paperless-db',
+            'captain',
+            false
+        )
+
+        expect(
+            getServiceNetworkAttachments(
+                ['captain-overlay-network', 'private-network'],
+                alias
+            )
+        ).toEqual([
+            {
+                Target: 'captain-overlay-network',
+                Aliases: ['srv-captain--paperless-db'],
+            },
+            {
+                Target: 'private-network',
+                Aliases: ['srv-captain--paperless-db'],
+            },
+        ])
+    })
+
+    test('does not add a redundant DNS alias to legacy apps', () => {
+        const alias = getLegacyServiceDnsAlias(
+            'srv-captain--paperless-db',
+            'captain',
+            true
+        )
+
+        expect(
+            getServiceNetworkAttachments(
+                ['captain-overlay-network'],
+                alias
+            )
+        ).toEqual([
+            {
+                Target: 'captain-overlay-network',
+            },
+        ])
+    })
+
     test('deletes both physical volumes when neither remains in use', async () => {
         const appsDataStore = new AppsDataStore(
             createConfigStore({}),