Merge pull request #47 from AVierwind/master

Add simple proxy

Author: simonh1000

README.md

@@ -111,6 +111,43 @@ module.exports = (argv) => {
 };
 ```
 
+## Http proxy
+
+#### Enabling proxy
+
+The server contains a simple http proxy. 
+The proxy must be configured in the config file.
+To enable this proxy:
+
+```sh
+angular-http-server --config configs/angular-http-server.config.js --useProxy true
+```
+
+#### configuring proxy
+
+To configure the proxy add a proxy object to your config file. 
+The proxy should be an array of configs with two required properties: a forward property which must be a string array listing url parts which should trigger the proxy, and a target property which should define the target to proxy to.
+The config can also contain an optional protocol option, when this is absent the server will default to https
+
+simple example:
+
+```js
+module.exports = {
+    proxy: [
+        {
+        forward: ['api/example-api', 'api-proxy/example'],
+        target: 'localhost:5000',
+        protocol: 'http'
+        },
+        {
+        forward: ['api/example-api-2', 'api-proxy-2/example'],
+        target: 'localhost:6000',
+        }
+    ],
+};
+```
+
+
 ## Self-Signed HTTPS Use
 
 #### Production

example/config/config.js

@@ -0,0 +1,13 @@
+module.exports = {
+    proxy: [
+        {
+            forward: ['beach.jpg', 'api-proxy/example'],
+            target: 'www.google.nl',
+        },
+        {
+            forward: ['api/example-api-2', 'image.svg'],
+            target: 'www.github.com',
+            protocol: 'http'
+        },
+    ],
+};

lib/angular-http-server.js

@@ -10,6 +10,7 @@ var opn = require("opn");
 
 var argv = require("minimist")(process.argv.slice(2));
 const getFilePathFromUrl = require('./get-file-path-from-url');
+const proxyHandler = require("./proxy");
 
 // Pre-process arguments
 const useHttps = argv.ssl || argv.https;
@@ -84,6 +85,10 @@ function start() {
 // HELPERS
 
 function requestListener(req, res) {
+    // When we hit the proxy, return
+    if (argv.proxy && proxyHandler(req, res, argv.proxy)) {
+            return;
+    }
     // Add CORS header if option chosen
     if (argv.cors) {
         res.setHeader("Access-Control-Allow-Origin", "*");

lib/proxy.js

@@ -0,0 +1,56 @@
+const httpProxy = require("http-proxy");
+
+var proxyServer = null;
+
+/**
+ * Simple Http Proxy, proxies request where url is contained in config to target from config
+ *
+ * @param req
+ * @param res
+ * @param {object} configs - proxyConfig from config file
+ * @return {boolean} - will return whether request is being proxied
+ */
+function proxyHandler(req, res, configs) {
+    if (!configs || configs.length === 0) {
+        throw new Error(
+            "no proxy configs present, please configure in your config file"
+        );
+    }
+    let proxyHit = false;
+    configs.forEach((config) => {
+        if (!proxyHit) {
+            if (!config.forward || config.forward.length === 0) {
+                throw new Error(
+                    "forward is missing or empty in your proxyConfig"
+                );
+            }
+
+            if (!config.target || config.target === "") {
+                throw new Error(
+                    "target is missing or empty in your proxyConfig"
+                );
+            }
+
+            proxyHit = config.forward.some(
+                (url) => req.url.indexOf(url) !== -1
+            );
+            if (proxyHit) {
+                const protocol = config.protocol ? config.protocol : "https";
+                console.log(
+                    `Proxying request ${req.method}, ${req.url} to ${protocol}://${config.target}`
+                );
+
+                if (proxyServer === null) {
+                    proxyServer = httpProxy.createProxyServer({});
+                }
+
+                proxyServer.web(req, res, {
+                    target: `${protocol}://${config.target}`,
+                });
+            }
+        }
+    });
+    return proxyHit;
+}
+
+module.exports = proxyHandler;

lib/proxy.spec.js

@@ -0,0 +1,85 @@
+const { expect } = require("chai");
+const proxyHandler = require("./proxy");
+const httpMock = require("node-mocks-http");
+
+describe("proxyHandler", () => {
+    it("should not proxy request to target when url from forward is not present", () => {
+        const config = [
+            {
+                forward: ["sample", "proxy-this"],
+                target: "www.github.com",
+            },
+        ];
+        const req = httpMock.createRequest({
+            method: "GET",
+            url: "https://localhost:4200/proxyTest",
+            pipe: () => {},
+        });
+
+        expect(proxyHandler(req, {}, config, false)).to.equal(false);
+    });
+
+    it("should proxy request to target when url from forward is present", () => {
+        const config = [
+            {
+                forward: ["sample", "proxy-this"],
+                target: "www.github.com",
+            },
+        ];
+        const req = httpMock.createRequest({
+            method: "GET",
+            url: "https://localhost:4200/proxyTest/proxy-this",
+            pipe: () => {},
+        });
+
+        expect(proxyHandler(req, {}, config, false)).to.equal(true);
+    });
+
+    it("should throw error when no config present", () => {
+        config = [];
+        const req = httpMock.createRequest({
+            method: "GET",
+            url: "https://localhost:4200/proxyTest/proxy-this",
+            pipe: () => {},
+        });
+
+        expect(() => proxyHandler(req, {}, null, false)).to.throw(
+            "no proxyConfig present, please configure in your config file"
+        );
+    });
+
+    it("should throw error when forward is missing", () => {
+        const config = [
+            {
+                forward: [],
+                target: "www.github.com",
+            },
+        ];
+        const req = httpMock.createRequest({
+            method: "GET",
+            url: "https://localhost:4200/proxyTest/proxy-this",
+            pipe: () => {},
+        });
+
+        expect(() => proxyHandler(req, {}, config, false)).to.throw(
+            "forward is missing or empty in your proxyConfig"
+        );
+    });
+    it("should throw error when target is missing", () => {
+        const config = [
+            {
+                forward: ["sample", "proxy-this"],
+                target: "",
+            },
+        ];
+        const req = httpMock.createRequest({
+            method: "GET",
+            url: "https://localhost:4200/proxyTest/proxy-this",
+            pipe: () => {},
+        });
+
+        expect(() => proxyHandler(req, {}, config, false)).to.throw(
+            "target is missing or empty in your proxyConfig"
+        );
+    });
+});