Maintain the prior behaviour of navy.url

If the given service isn't running, return a postulated url instead.

Author: tanuck

packages/navy/src/navy/index.js

@@ -14,7 +14,7 @@ import {loadPlugins} from './plugin-interface'
 import {middlewareRunner} from './middleware'
 import {reconfigureHTTPProxy} from '../http-proxy'
 import {getExternalIP} from '../util/external-ip'
-import {getUrlFromService} from '../util/service-host'
+import {createUrlForService, getUrlFromService} from '../util/service-host'
 
 import type {Driver, CreateDriver} from '../driver'
 import type {ConfigProvider, CreateConfigProvider} from '../config-provider'
@@ -520,7 +520,7 @@ export class Navy extends EventEmitter2 {
    */
   async url(service: string): Promise<?string> {
     const ps = await (await this.safeGetDriver()).ps(service)
-    return getUrlFromService(ps.pop())
+    return getUrlFromService(ps.pop()) || createUrlForService(service, this.normalisedName, await this.externalIP())
   }
 
   /**

packages/navy/src/util/__tests__/service-host.js

@@ -1,7 +1,7 @@
 /* eslint-env mocha */
 
 import {expect} from 'chai'
-import {getNIPSubdomain, getUrlFromService, createHostForService} from '../service-host'
+import {getNIPSubdomain, getUrlFromService, createHostForService, createUrlForService} from '../service-host'
 
 describe('service-host', function () {
 
@@ -20,13 +20,20 @@ describe('service-host', function () {
 
   describe('createHostForService', function () {
 
-    it('should return the correct url host for a service', async function () {
+    it('should return the correct host for a service', async function () {
       expect(await createHostForService('someservice', 'mynavy', '127.0.0.1')).to.equal('someservice.mynavy.127.0.0.1.nip.io')
       expect(await createHostForService('someservice', 'mynavy', '192.168.1.10')).to.equal('someservice.mynavy.192.168.1.10.nip.io')
     })
 
   })
 
+  describe('createUrlForService', function () {
+
+    it('should return the correct url for a service', async function () {
+      expect(await createUrlForService('someservice', 'mynavy', '192.168.99.100')).to.equal('http://someservice.mynavy.192.168.99.100.nip.io')
+    })
+  })
+
   describe('getUrlFromService', function () {
 
     it('should extract the host from service ENV config', function () {

packages/navy/src/util/service-host.js

@@ -21,6 +21,10 @@ export async function createHostForService(service: string, navyNormalisedName:
   return `${service}.${navyNormalisedName}.${process.env.NAVY_EXTERNAL_SUBDOMAIN || await getNIPSubdomain(externalIP)}`
 }
 
+export async function createUrlForService(service: string, navyNormalisedName: string, externalIP: string) {
+  return `http://${await createHostForService(service, navyNormalisedName, externalIP)}`
+}
+
 export function getUrlFromService(service: Service) {
   if (!service || !service.raw || !service.raw.Config || !service.raw.Config.Env) {
     return null