add rudimentary noproxy support

lib/install.js

@@ -14,6 +14,7 @@ const makeDir = require('make-dir');
 // for fetching binaries
 const fetch = require('node-fetch');
 const tar = require('tar');
+const url = require('url');
 
 let npgVersion = 'unknown';
 try {
@@ -24,6 +25,34 @@ try {
   // do nothing
 }
 
+function should_proxy(uri, noProxyList) {
+  const { hostname, port } = url.parse(uri);
+
+  /* TODO: Default ports as defined by the protocol should still
+     match, they currently will not if the noProxyList entry
+     explicitly specifies the default port. */
+
+  // eslint-disable-next-line eqeqeq
+  const portMatch = (entry) => entry.port === undefined || entry.port == port;
+
+  for (let i = 0; i < noProxyList && noProxyList.length; i++) {
+    const entry = noProxyList[i];
+    if (!portMatch(entry)) {
+      continue;
+    }
+    // TODO: Deal with 'partial wildcards': *.foo.com
+    if (entry.hostSuffix === '*') {
+      return false;
+    }
+    const rightSideMatch = hostname.indexOf(entry.hostSuffix, hostname.length, entry.hostSuffix.length);
+    if (rightSideMatch > -1) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
 function place_binary(uri, targetDir, opts, callback) {
   log.http('GET', uri);
 
@@ -54,8 +83,18 @@ function place_binary(uri, targetDir, opts, callback) {
                     process.env.http_proxy ||
                     process.env.HTTP_PROXY ||
                     process.env.npm_config_proxy;
+  const noProxy = opts.noproxy ||
+                    process.env.no_proxy ||
+                    process.env.NO_PROXY ||
+                    process.env.npm_config_noproxy;
+  // TODO: IPv6 address + port support.
+  const noProxyList = noProxy && noProxy.split(',').map((e) => {
+    const [hostSuffix, port] = e.split(':');
+    return { hostSuffix, port };
+  });
+
   let agent;
-  if (proxyUrl) {
+  if (proxyUrl && should_proxy(sanitized, noProxyList)) {
     const ProxyAgent = require('https-proxy-agent');
     agent = new ProxyAgent(proxyUrl);
     log.http('download', 'proxy agent configured using: "%s"', proxyUrl);

lib/node-pre-gyp.js

@@ -113,6 +113,7 @@ proto.configDefs = {
   debug: Boolean,    // 'build'
   directory: String, // bin
   proxy: String,     // 'install'
+  noproxy: String,   // 'install'
   loglevel: String  // everywhere
 };