feat(cli): instance proxy server (#635)

* feat(cli): instance proxy server

* docs: add proxy docs

cli/package.json

@@ -43,10 +43,12 @@
  "fs-extra": "^8.1.0",
  "gaze": "^1.1.3",
  "handlebars": "^4.3.3",
+ "http-proxy": "^1.18.1",
  "i18next-conv": "^9",
  "i18next-scanner": "^2.10.3",
  "inquirer": "^7.3.3",
  "lodash": "^4.17.11",
+ "node-http-proxy-json": "^0.1.9",
  "parse-author": "^2.0.0",
  "parse-gitignore": "^1.0.1",
  "styled-jsx": "<3.3.3",

cli/src/commands/start.js

@@ -7,6 +7,7 @@ const i18n = require('../lib/i18n')
 const loadEnvFiles = require('../lib/loadEnvFiles')
 const parseConfig = require('../lib/parseConfig')
 const makePaths = require('../lib/paths')
+const createProxyServer = require('../lib/proxy')
 const { compileServiceWorker } = require('../lib/pwa')
 const makeShell = require('../lib/shell')
 const { validatePackage } = require('../lib/validatePackage')
@@ -18,6 +19,8 @@ const handler = async ({
  force,
  port = process.env.PORT || defaultPort,
  shell: shellSource,
+ proxy,
+ proxyPort,
 }) => {
  const paths = makePaths(cwd)
 
@@ -36,6 +39,29 @@ const handler = async ({
  process.exit(1)
  }
 
+ const newPort = await detectPort(port)
+
+ if (proxy) {
+ const newProxyPort = await detectPort(proxyPort)
+ const proxyBaseUrl = `http:https://localhost:${newProxyPort}`
+
+ reporter.print('')
+ reporter.info('Starting proxy server...')
+ reporter.print(
+ `The proxy for ${chalk.bold(
+ proxy
+ )} is now available on port ${newProxyPort}`
+ )
+ reporter.print('')
+
+ createProxyServer({
+ target: proxy,
+ baseUrl: proxyBaseUrl,
+ port: newProxyPort,
+ shellPort: newPort,
+ })
+ }
+
  await exitOnCatch(
  async () => {
  if (!(await validatePackage({ config, paths, offerFix: false }))) {
@@ -77,7 +103,6 @@ const handler = async ({
  reporter.info('Generating manifests...')
  await generateManifests(paths, config, process.env.PUBLIC_URL)
 
- const newPort = await detectPort(port)
  if (String(newPort) !== String(port)) {
  reporter.print('')
  reporter.warn(
@@ -123,6 +148,16 @@ const command = {
  type: 'number',
  description: 'The port to use when running the development server',
  },
+ proxy: {
+ alias: 'P',
+ type: 'string',
+ description: 'The remote DHIS2 instance the proxy should point to',
+ },
+ proxyPort: {
+ type: 'number',
+ description: 'The port to use when running the proxy',
+ default: 8080,
+ },
  },
  handler,
 }

cli/src/lib/proxy.js

@@ -0,0 +1,127 @@
+const url = require('url')
+const { reporter } = require('@dhis2/cli-helpers-engine')
+const httpProxy = require('http-proxy')
+const _ = require('lodash')
+const transformProxyResponse = require('node-http-proxy-json')
+
+const stripCookieSecure = cookie => {
+ return cookie
+ .split(';')
+ .filter(v => v.trim().toLowerCase() !== 'secure')
+ .join('; ')
+}
+
+const rewriteLocation = ({ location, target, baseUrl }) => {
+ const parsedLocation = url.parse(location)
+ const parsedTarget = url.parse(target)
+ const parsedBaseUrl = url.parse(baseUrl)
+
+ if (
+ parsedLocation.host === parsedTarget.host &&
+ parsedLocation.pathname.startsWith(parsedTarget.pathname)
+ ) {
+ return url.format({
+ ...parsedBaseUrl,
+ pathname: parsedLocation.pathname.replace(
+ parsedTarget.pathname,
+ ''
+ ),
+ search: parsedLocation.search,
+ })
+ }
+ return location
+}
+
+const isUrl = string => {
+ try {
+ const { protocol } = new URL(string)
+ return protocol === 'http:' || protocol === 'https:'
+ } catch (error) {
+ return false
+ }
+}
+
+const transformJsonResponse = (res, { target, baseUrl }) => {
+ switch (typeof res) {
+ case 'string':
+ if (isUrl(res)) {
+ return rewriteLocation({ location: res, target, baseUrl })
+ }
+ return res
+ case 'object':
+ if (Array.isArray(res)) {
+ return res.map(r =>
+ transformJsonResponse(r, { target, baseUrl })
+ )
+ }
+ return _.transform(
+ res,
+ (result, value, key) => {
+ result[key] = transformJsonResponse(value, {
+ target,
+ baseUrl,
+ })
+ },
+ {}
+ )
+ default:
+ return res
+ }
+}
+
+exports = module.exports = ({ target, baseUrl, port, shellPort }) => {
+ const proxyServer = httpProxy.createProxyServer({
+ target,
+ changeOrigin: true,
+ secure: false,
+ protocolRewrite: 'http',
+ cookieDomainRewrite: '',
+ cookiePathRewrite: '/',
+ })
+
+ proxyServer.on('proxyRes', (proxyRes, req, res) => {
+ if (proxyRes.headers['access-control-allow-origin']) {
+ res.setHeader(
+ 'access-control-allow-origin',
+ `http:https://localhost:${shellPort}`
+ )
+ }
+
+ if (proxyRes.headers.location) {
+ proxyRes.headers.location = rewriteLocation({
+ location: proxyRes.headers.location,
+ target,
+ baseUrl,
+ })
+ }
+
+ const sc = proxyRes.headers['set-cookie']
+ if (Array.isArray(sc)) {
+ proxyRes.headers['set-cookie'] = sc.map(stripCookieSecure)
+ }
+
+ if (
+ proxyRes.headers['content-type'] &&
+ proxyRes.headers['content-type'].includes('application/json')
+ ) {
+ transformProxyResponse(res, proxyRes, body => {
+ if (body) {
+ return transformJsonResponse(body, {
+ target,
+ baseUrl,
+ })
+ }
+ return body
+ })
+ }
+ })
+
+ proxyServer.on('error', error => {
+ reporter.warn(error)
+ })
+
+ proxyServer.listen(port)
+}
+
+exports.rewriteLocation = rewriteLocation
+exports.transformJsonResponse = transformJsonResponse

cli/src/lib/proxy.test.js

@@ -0,0 +1,91 @@
+const { rewriteLocation, transformJsonResponse } = require('./proxy')
+
+describe('transformJsonResponse', () => {
+ it('rewrites URLs in responses if they match the proxy target', () => {
+ const transformedResponse = transformJsonResponse(
+ {
+ a: {
+ b: {
+ c: 'https://play.dhis2.org/dev/api/endpoint',
+ },
+ },
+ },
+ {
+ target: 'https://play.dhis2.org/dev',
+ baseUrl: 'http:https://localhost:8080',
+ }
+ )
+
+ expect(transformedResponse.a.b.c).toBe(
+ 'http:https://localhost:8080/api/endpoint'
+ )
+ })
+})
+
+describe('rewriteLocation', () => {
+ it('rewrites locations if they match the proxy target', () => {
+ const baseUrl = 'http:https://localhost:8080'
+
+ expect(
+ rewriteLocation({
+ location: 'https://play.dhis2.org/dev/login.action',
+ target: 'https://play.dhis2.org/dev',
+ baseUrl,
+ })
+ ).toBe(`${baseUrl}/login.action`)
+
+ expect(
+ rewriteLocation({
+ location: 'https://play.dhis2.org/dev/page?param=value',
+ target: 'https://play.dhis2.org/dev',
+ baseUrl,
+ })
+ ).toBe(`${baseUrl}/page?param=value`)
+
+ expect(
+ rewriteLocation({
+ location: 'https://server.com:1234',
+ target: 'https://server.com:5678',
+ baseUrl,
+ })
+ ).toBe('https://server.com:1234')
+
+ expect(
+ rewriteLocation({
+ location: 'https://server.com',
+ target: 'http:https://server.com',
+ baseUrl,
+ })
+ ).toBe(baseUrl)
+
+ expect(
+ rewriteLocation({
+ location: 'https://play.dhis2.org/dev/api/dev',
+ target: 'https://play.dhis2.org/dev',
+ baseUrl,
+ })
+ ).toBe(`${baseUrl}/api/dev`)
+ })
+
+ it('does not rewrite locations if they do not match the proxy target', () => {
+ ;[
+ {
+ location: 'https://example.com/path',
+ target: 'https://play.dhis2.org/dev',
+ baseUrl: 'http:https://localhost:8080',
+ },
+ {
+ location: 'https://play.dhis2.org/2.35dev',
+ target: 'https://play.dhis2.org/dev',
+ baseUrl: 'http:https://localhost:8080',
+ },
+ {
+ location: 'http:https://server.com:1234',
+ target: 'http:https://server.com:5678',
+ baseUrl: 'http:https://localhost:8080',
+ },
+ ].forEach(args => {
+ expect(rewriteLocation(args)).toBe(args.location)
+ })
+ })
+})

docs/_sidebar.md

@@ -21,5 +21,6 @@
 - [**PWA**](pwa/pwa)
 - [**Architecture**](architecture)
 - [**Troubleshooting**](troubleshooting.md)
+- [**Proxy**](proxy.md)
 -  
 - [Changelog](CHANGELOG.md)

docs/proxy.md

@@ -0,0 +1,14 @@
+# Proxy
+
+When developing against a remote instance, some browsers may block cookies due
+to the cross-site nature of requests.
+
+As a workaround, the [`start`](scripts/start.md) command provides a `--proxy`
+option. The value of this option is the remote instance that a local proxy will
+route requests to.
+
+## Usage
+
+```
+d2-app-scripts start --proxy <remote instance URL>
+```

docs/scripts/start.md

@@ -21,4 +21,6 @@ Global Options:
 Options:
  --cwd working directory to use (defaults to cwd)
  --port, -p The port to use when running the development server [number]
+ --proxy, -P The remote DHIS2 instance the proxy should point to [string]
+ --proxyPort The port to use when running the proxy [number] [default: 8080]
 ```

docs/troubleshooting.md

@@ -8,8 +8,11 @@ A DHIS2 application needs to talk to a [DHIS2 server](https://www.dhis2.org/down
 
 You should specify the fully-qualified base URL of a running DHIS2 server (including the `http:https://` or `https://` protocol) in the **Server** field of the login dialog.
 
-Make sure that the the URL of your application (`localhost:3000` in this case) is included in the DHIS2 server's CORS whitelist (System Settings -> Access). Also ensure that the server
-you specify doesn't have any domain-restricting proxy settings (such as the `SameSite=Lax`).
+Make sure that the the URL of your application (`localhost:3000` in this case)
+is included in the DHIS2 server's CORS whitelist (System Settings -> Access). If
+your server or browser has domain-restricting settings (such as the
+`SameSite=Lax`), the [`--proxy`](proxy.md) option of the
+[`start`](scripts/start.md) command may be helpful.
 
 For testing purposes, `https://play.dhis2.org/dev` will NOT work because it is configured for secure same-site access, while `https://debug.dhis2.org/dev` should work.
 

yarn.lock

@@ -4851,6 +4851,11 @@ buffer@^5.1.0, buffer@^5.5.0:
  base64-js "^1.3.1"
  ieee754 "^1.1.13"
 
+bufferhelper@^0.2.1:
+ version "0.2.1"
+ resolved "https://registry.yarnpkg.com/bufferhelper/-/bufferhelper-0.2.1.tgz#fa74a385724a58e242f04ad6646c2366f83b913e"
+ integrity sha1-+nSjhXJKWOJC8ErWZGwjZvg7kT4=
+
 builtin-modules@^3.1.0:
  version "3.1.0"
  resolved "https://registry.yarnpkg.com/builtin-modules/-/builtin-modules-3.1.0.tgz#aad97c15131eb76b65b50ef208e7584cd76a7484"
@@ -5541,7 +5546,7 @@ [email protected]:
  resolved "https://registry.yarnpkg.com/concat-map/-/concat-map-0.0.1.tgz#d8a96bd77fd68df7793a73036a3ba0d5405d477b"
  integrity sha1-2Klr13/Wjfd5OnMDajug1UBdR3s=
 
-concat-stream@^1.5.0:
+concat-stream@^1.5.0, concat-stream@^1.5.1:
  version "1.6.2"
  resolved "https://registry.yarnpkg.com/concat-stream/-/concat-stream-1.6.2.tgz#904bdf194cd3122fc675c77fc4ac3d4ff0fd1a34"
  integrity sha512-27HBghJxjiZtIk3Ycvn/4kbJk/1uZuJFfuPEns6LaEvpvG1f0hTea8lilrouyo9mVc2GWdcEZ8OLoGmSADlrCw==
@@ -8389,6 +8394,15 @@ http-proxy@^1.17.0:
  follow-redirects "^1.0.0"
  requires-port "^1.0.0"
 
+http-proxy@^1.18.1:
+ version "1.18.1"
+ resolved "https://registry.yarnpkg.com/http-proxy/-/http-proxy-1.18.1.tgz#401541f0534884bbf95260334e72f88ee3976549"
+ integrity sha512-7mz/721AbnJwIVbnaSv1Cz3Am0ZLT/UBwkC92VlxhXv/k/BBQfM2fXElQNC27BVGr0uwUpplYPQM9LnaBMR5NQ==
+ dependencies:
+ eventemitter3 "^4.0.0"
+ follow-redirects "^1.0.0"
+ requires-port "^1.0.0"
+
 http-signature@~1.2.0:
  version "1.2.0"
  resolved "https://registry.yarnpkg.com/http-signature/-/http-signature-1.2.0.tgz#9aecd925114772f3d95b65a60abb8f7c18fbace1"
@@ -11215,6 +11229,14 @@ node-gettext@^2.0.0:
  dependencies:
  lodash.get "^4.4.2"
 
+node-http-proxy-json@^0.1.9:
+ version "0.1.9"
+ resolved "https://registry.yarnpkg.com/node-http-proxy-json/-/node-http-proxy-json-0.1.9.tgz#5e744138c189ebd7e0105fe92d035a5486478cd4"
+ integrity sha512-WrKAR/y09BWaz5WqgbxuE6D/XsdhQFkLkSdnRk0a5uBKSINtApMV085MN7JMh+stiyBBltvgSR9SYVIZIpKKKQ==
+ dependencies:
+ bufferhelper "^0.2.1"
+ concat-stream "^1.5.1"
+
 node-int64@^0.4.0:
  version "0.4.0"
  resolved "https://registry.yarnpkg.com/node-int64/-/node-int64-0.4.0.tgz#87a9065cdb355d3182d8f94ce11188b825c68a3b"