feat: support several target registries

closes #62

README.md

@@ -237,7 +237,7 @@ type TCacheFactory = {
 }
 
 type TFirewallConfig = {
-  registry: string
+  registry: string | string[]
   entrypoint?: string
   token?: string
   base?: string

src/main/js/config.js

@@ -90,7 +90,7 @@ const populate = (config) => {
 
       return {
         rules,
-        registry: normalizePath(f.registry),
+        registry: f.registry ? asArray(f.registry).map(normalizePath) : null,
         token: f.token,
         entrypoint: f.entrypoint ? normalizePath(f.entrypoint) : null,
         base: f.base || '/',

src/main/js/firewall/packument.js

@@ -1,6 +1,6 @@
 import {getDirectives, getPolicy} from './engine.js'
 import {request} from '../http/index.js'
-import {makeDeferred} from '../util.js'
+import {asArray, makeDeferred, tryQueue} from '../util.js'
 
 export const getPackument = async ({boundContext, rules}) => {
   const {cache, registry, authorization, entrypoint, name} = boundContext
@@ -11,12 +11,12 @@ export const getPackument = async ({boundContext, rules}) => {
   cache.add(name, promise)
 
   try {
-    const {body, headers} = await request({
-      url: `${registry}/${name}`,
+    const args = asArray(registry).map(r => [{
+      url: `${r}/${name}`,
       authorization,
       'accept-encoding': 'gzip'
-    })
-
+    }])
+    const {body, headers} = await tryQueue(request, ...args)
     const packument = JSON.parse(body)
     const directives = await getDirectives({ packument, rules, boundContext})
     const _packument = patchPackument({ packument, directives, entrypoint, registry })
@@ -39,7 +39,10 @@ export const patchVersions = ({packument, directives, entrypoint, registry}) =>
   if (getPolicy(directives, v.version) === 'deny') {
     return m
   }
-  v.dist.tarball = v.dist.tarball.replace(registry, entrypoint)
+  asArray(registry).forEach(r => {
+    v.dist.tarball = v.dist.tarball.replace(r, entrypoint)
+  })
+
   m[v.version] = v
   return m
 }, {})

src/main/js/firewall/plugins/audit.js

@@ -1,7 +1,7 @@
 import {semver} from '../../semver.js'
 import {request} from '../../http/index.js'
 import {getCache} from '../../cache.js'
-import {makeDeferred} from '../../util.js'
+import {asArray, makeDeferred, tryQueue} from '../../util.js'
 
 const severityOrder = ['critical', 'high', 'moderate', 'low', 'any' ]
 
@@ -16,6 +16,13 @@ export const auditPlugin = async ({entry: {name, version}, options = {}, boundCo
 }
 
 const getAdvisories = async (name, registry) => {
+  const registries = asArray(registry || registry)
+  const args = registries.map(r => [name, r])
+
+  return tryQueue(_getAdvisories, ...args)
+}
+
+const _getAdvisories = async (name, registry) => {
   const cache = getCache({ name: 'audit', ttl: 120_000 })
   if (await cache.has(name)) {
     return cache.get(name)

src/main/js/index.d.ts

@@ -68,7 +68,7 @@ type TCacheFactory = {
 }
 
 type TFirewallConfig = {
-  registry: string
+  registry: string | string[]
   entrypoint?: string
   token?: string
   base?: string

src/main/js/mwares/proxy.js

@@ -1,6 +1,14 @@
 import {request} from '../http/client.js'
+import {asArray, tryQueue} from '../util.js'
 
 export const proxy = (registry) => async (req, res) => {
-  const url = `${registry}${req.url}`
-  await request({ url, method: req.method, pipe: {req, res}, followRedirects: true})
+  const registries = asArray(registry)
+  const args = registries.map(r => [{
+    url: `${r}${req.url}`,
+    method: req.method,
+    pipe: {req, res},
+    followRedirects: true
+  }])
+
+  return tryQueue(request, ...args)
 }

src/main/js/util.js

@@ -123,3 +123,15 @@ export const mergeDeep = (target, ...sources) => {
 
   return mergeDeep(target, ...sources)
 }
+
+export const tryQueue = async (fn, ...args) => {
+  const results = await Promise.allSettled(args.map(a => fn(...a)))
+  const success = results.find(r => r.status === 'fulfilled')
+
+  if (success) {
+    return success.value
+  }
+
+  const error = results.find(r => r.status === 'rejected')
+  return Promise.reject(error.reason)
+}

src/test/js/app.js

@@ -23,7 +23,7 @@ const app = createApp([{
 }, {
   server: { port: 3003 },
   firewall: {
-    registry: 'https://registry.yarnpkg.com',
+    registry: ['https://registry.yarnpkg.com', 'https://registry.npmjs.org'],
     rules: { policy: 'deny', name: '*' }
   }
 }])

src/test/js/util.js

@@ -1,5 +1,5 @@
 import {testFactory, assert} from '../test-utils.js'
-import {flatten, expand} from '../../main/js/util.js'
+import {flatten, expand, tryQueue} from '../../main/js/util.js'
 
 const test = testFactory('util', import.meta)
 
@@ -27,3 +27,18 @@ test('expand', () => {
     baz: [{a: 'a'}, {b: {c: 'd'}}, 1]
   })
 })
+
+test('tryQueue', async() => {
+  const fn = async (i) => {
+    if (i === 0) { throw new Error('broken') }
+    return i
+  }
+
+  assert.equal(await tryQueue(fn, [0], [0], [3]), 3)
+
+  try {
+    await tryQueue(fn, [0])
+  } catch (err) {
+    assert.equal(err.message, 'broken')
+  }
+})