Add Specify Port Of CRA's Webpack Dev Server as a webpack til

README.md

@@ -10,7 +10,7 @@ smart people at [Hashrocket](http://hashrocket.com/).
 For a steady stream of TILs from a variety of rocketeers, checkout
 [til.hashrocket.com](https://til.hashrocket.com/).
 
-_545 TILs and counting..._
+_546 TILs and counting..._
 
 ---
 
@@ -646,6 +646,7 @@ _545 TILs and counting..._
 - [Better Module Imports With Aliases](webpack/better-module-imports-with-aliases.md)
 - [Debugging With Full Source Maps](webpack/debugging-with-full-source-maps.md)
 - [Run ESLint As A Preloader](webpack/run-eslint-as-a-preloader.md)
+- [Specify Port Of CRA's Webpack Dev Server](webpack/specify-port-of-cra-webpack-dev-server.md)
 - [Use A Specific Config File](webpack/use-a-specific-config-file.md)
 
 ## Usage

webpack/specify-port-of-cra-webpack-dev-server.md

@@ -0,0 +1,15 @@
+# Specify Port Of CRA's Webpack Dev Server
+
+[`create-react-app`](https://github.com/facebookincubator/create-react-app)
+gives you a set of scripts, one of which allows you to start a development
+server that bundles and serves your javascript. This is handled under the
+hood via `webpack-dev-server`. By default it attempts to serve from port
+`3000`. If port `3000` is taken it will attempt to connect to another
+sequential port.
+
+Alternatively, you can just specify the port when starting the development
+server. This can be done with the `PORT` env var.
+
+```bash
+$ PORT=3333 yarn start
+```