Updating Readme

README.md

@@ -1,2 +1,109 @@
-# Go NPM
+## Go NPM
 ### Distribute cross-platform Go binaries via NPM
+
+Applications written in Golang are portable - you can easily cross-compile binaries that work on Windows, Mac, and Linux. But how do you distribute the binaries to customers? When you publish new releases, how do they update the binary? 
+
+**Use NPM to distribute cross-platform Go binaries**
+
+## Kidding me! Why NPM?
+* **Cross-platform**: NPM is the only popular package manager that works cross-platform. 
+* **Lower barier to entry**: Most developers have NPM installed already. 
+* **Pain free publishing**: It just takes one command to publish - `npm publish`
+* **Dead simple install & update story**: `npm install/update -g your-awesome-app`
+* **Adds $PATH**: NPM will automatically add your binary location to $PATH and generate .cmd file for Windows. Your app just works after installation! 
+
+## Okay, tell me how?
+### 1. Publish your binaries
+Setup your Go application to compile and publish binaries to a file server. This could be Github Releases or Amazon S3 or even Dropbox. All you need is a link.
+
+I like to use [GoReleaser](https://github.com/goreleaser/goreleaser) to setup by release process. You create a simple YAML configuration file like this and run `goreleaser` CLI to publish binaries for various platform/architecture combination to Github:
+
+```
+# .goreleaser.yml
+# Build customization
+builds:
+  - binary: drum-roll
+    goos:
+      - windows
+      - darwin
+      - linux
+    goarch:
+      - amd64
+```
+
+`go-npm` will pull the appropriate binary for the platform & architecture where the package is being installed.
+
+### 2. Create a package.json file for your NPM app
+To publish to NPM, you need to create a `package.json` file. You give your application a name, link to Readme, Github repository etc, and more importantly add `go-npm` as a dependency. You can create this file in an empty directory in your project or in a separate Git repository altogether. It is your choice.
+
+**Create package.json**
+
+`$ npm init`
+
+Answer the questions to create an initial package.json file
+
+**Add go-npm dependency**
+
+From the directory containing package.json file, do
+
+`$ npm install go-npm --save`
+
+This will install go-npm under to your package.json file. It will also create a `node_modules` directory where the `go-npm` package is downloaded. You don't need this directory since you are only going to publish the module and not consume it yourself. Let's go ahead and delete it.
+
+`$ rm -r node_modules`
+
+**Add postinstall and preuninstall scripts**
+Here is the magic: You ask to run `go-npm install` after it completes installing your package. This will pull down binaries from Github or Amazon S3 and install in NPM's `bin` directory. Binaries under bin directory are immediately available for use in your Terminal.
+
+Edit `package.json` file and add the following:
+```
+{
+    "postinstall": "go-npm install",
+    "preuninstall": "go-npm uninstall",
+}
+```
+
+`go-npm uninstall` simply deletes the binary from `bin` directory before NPM uninstalls your package.
+
+**Configure your binary path**
+
+You need to tell `go-npm` where to download the binaries from, and where to install them. Edit `package.json` file and add the following configuration.
+
+```
+"goBinary": {
+      "name": "command-name",
+      "path": "./bin",
+      "url": "https://github.com/user/my-go-package/releases/download/v{{version}}/myGoPackage_{{version}}_{{platform}}_{{arch}}.tar.gz"
+```
+
+* *name*: Name of the command users will use to run your binary. 
+* *path*: Temporary path where binaries will be downloaded to
+* *url*: HTTP Web server where binaries are hosted.
+
+Following variables are available to customize the URL:
+* `{{version}}`: Version number read from  `package.json` file. When you publish your package to NPM, it will use this version number. Ex: 0.0.1
+* `{{platform}}`: `$GOOS` value for the platform
+* `{{arch}}`: `$GOARCH` value for the architecture
+
+If you use `goreleaser` to publish your modules, it will automatically set the right architecture & platform in your URL.
+
+**Publish to NPM**
+
+All that's left now is publish to NPM. As I promised before, just one command
+
+`$ npm publish`
+
+### 3. Distribute to users
+
+To install:
+
+`npm install -g your-app-name`
+
+To Update:
+
+`npm update -g your-app-name`
+
+
+---
+
+With ❤️ to the community by [Sanath Kumar Ramesh](http://twitter.com/sanathkr_)