Add process manager guide

docs/.vuepress/config.js

@@ -186,6 +186,7 @@ module.exports = {
             '/3.0.0-beta.x/guides/update-version',
             '/3.0.0-beta.x/guides/databases',
             '/3.0.0-beta.x/guides/deployment',
+            '/3.0.0-beta.x/guides/process-manager',
             '/3.0.0-beta.x/guides/jwt-validation',
             '/3.0.0-beta.x/guides/error-catching',
             '/3.0.0-beta.x/guides/external-data',

docs/3.0.0-beta.x/guides/process-manager.md

@@ -0,0 +1,83 @@
+---
+sidebarDepth: 2
+---
+
+# Process manager
+
+In this guide we will see how you can start a Strapi application using a process manager.
+
+::: tip
+In this example we will use [PM2](https://pm2.keymetrics.io/).
+:::
+
+## Install PM2
+
+PM2 allows you to keep your Strapi project alive and to reload it without downtime.
+
+You will install PM2 globally
+
+:::: tabs
+
+::: tab yarn
+`yarn global add pm2`
+:::
+
+::: tab npm
+`npm install pm2 -g`
+:::
+
+::::
+
+## Basic usage
+
+### Starting with server.js file
+
+The basic usage to start an application with PM2 will be to run a command like this `pm2 start server.js`.
+
+But here we are facing an issue. In your project you don't have a `.js` file to run your Strapi application.
+
+So first let's create a `server.js` file that will let you run the `pm2` command.
+
+**Path —** `./server.js`
+
+```js
+const strapi = require('strapi');
+strapi().start();
+```
+
+Now you will be able to start your server by running `pm2 start server.js`.
+
+### Starting with strapi command
+
+By default there is two important commands.
+
+- `yarn develop` to start your project in development mode.
+- `yarn start` to start your app for production.
+
+You can also start your process manager using the `yarn start` command.
+
+`pm2 start npm --no-automation --name app -- run start`
+
+## Configuration file
+
+PM2 let you create a config file to save all information to start your sever properly at anytime.
+
+By running `pm2 init` it will init an `ecosystem.config.js` in your application.
+
+Then replace the content of this files by the following code
+
+```js
+module.exports = {
+  apps: [
+    {
+      name: 'app',
+      script: 'npm',
+      args: 'start',
+    },
+  ],
+};
+```
+
+And then run `pm2 start ecosystem.config.js` to start the pm2 process.
+
+You can see the full documentation of available configuration in the [PM2 ecosystem file documentation](https://pm2.keymetrics.io/docs/usage/application-declaration/).