# Deployments

# Introduction

Of course, one of the primary features of Laravel Vapor is atomic, zero-downtime deployments. Unlike many other features of Vapor, deployments are only initiated via the Vapor CLI. During deployment, Vapor will run the build steps of your vapor.yml file on the local machine that the deployment is running on. This might be your personal machine or a continuous integration platform.

# Initiating Deployments

To initiate a deployment, execute the deploy CLI command from the root of your application:

vapor deploy production

# Build Hooks

You may define build hooks for an environment using the build key within your vapor.yml file. These commands are executed on the local machine that the deployment is running on and may be used to prepare your application for deployment. During deployment, your application is built within a temporary .vapor directory that is created by the CLI and all of your build commands will run within that temporary directory:

id: 3
name: vapor-app
environments:
    production:
        memory: 1024
        database: vapor-app
        cache: vapor-cache
        build:
            - 'composer install --no-dev'
            - 'php artisan event:cache'
        deploy:
            - 'php artisan migrate --force'

# Deploy Hooks

You may define deployment hooks for an environment using the deploy key within your vapor.yml file. These commands are executed against the deployed environment before it is activated for general availability. If any of these commands fail, the deployment will not be activated. You may review the output / logs from your deployment hooks via the Vapor UI's deployment detail screen:

id: 3
name: vapor-app
environments:
    production:
        memory: 1024
        database: vapor-app
        cache: vapor-cache
        build:
            - 'composer install --no-dev'
            - 'php artisan event:cache'
        deploy:
            - 'php artisan migrate --force'

# Assets

During deployment, Vapor will automatically extract all of the assets in your Laravel project's public directory and upload them to S3. In addition, Vapor will create a AWS CloudFront (CDN) distribution to distribute these assets efficiently around the world.

Because all of your assets will be served via S3 / CloudFront, you should always generate URLs to these assets using Laravel's asset helper. Vapor injects an ASSET_URL environment variable which Laravel's asset helper will use when constructing your URLs:

<img src="{{ asset('img.jpg') }}">

On subsequent deployments, only the assets that have changed will be uploaded to S3, while unchanged assets will be copied over from the previous deployment.

# Code Splitting / Dynamic Imports

If you are taking advantage of dynamic imports and code splitting in your project, you will need to let Webpack know where the child chunks will be loaded from for each deployment. To accomplish this, you can take advantage of the ASSET_URL variable that Laravel Vapor injects into your environment during your build step:

const mix = require("laravel-mix");

/*
 |--------------------------------------------------------------------------
 | Mix Asset Management
 |--------------------------------------------------------------------------
 |
 | Mix provides a clean, fluent API for defining some Webpack build steps
 | for your Laravel application. By default, we are compiling the Sass
 | file for the application as well as bundling up all the JS files.
 |
 */

mix
  .js("resources/js/app.js", "public/js")
  .sass("resources/sass/app.scss", "public/css");

if (mix.inProduction()) {
    const ASSET_URL = process.env.ASSET_URL + "/";

    mix.webpackConfig(webpack => {
        return {
            plugins: [
                new webpack.DefinePlugin({
                    "process.env.ASSET_PATH": JSON.stringify(ASSET_URL)
                })
            ],
            output: {
                publicPath: ASSET_URL
            }
        };
    });
}

# Hot Module Replacement

If you are using code splitting and "hot module replacement" during local development, you will need to use the mix helper locally and the asset helper when deploying to Vapor:

 @if (app()->environment('local'))
    <link href="{{ mix('css/admin/app.css') }}" rel="stylesheet">
    <script src="{{ mix('js/admin/app.js') }}"></script>
@else
    <link href="{{ asset('css/admin/app.css') }}" rel="stylesheet">
    <script src="{{ asset('js/admin/app.js') }}" defer></script>
@endif

# URLs Within CSS

Sometimes, your CSS may need to reference asset URLs, such as a background-image property that references an image via URL. Obviously, you are not able to use the PHP asset helper within your CSS. For this reason, Vapor will automatically prepend the correct asset base URL to all relative URLs in your CSS during the build process. After your build steps have executed, Vapor performs this action against any CSS files in your application's public directory (including directories nested under public).

# Redeploying

Sometimes you may need to simply redeploy a given environment without rebuilding it. For example, you may wish to do this after updating an environment variable. To accomplish this, you may use the Vapor UI or the redeploy CLI command:

vapor redeploy production

# Rollbacks

To rollback to a previous deployment, you may select the deployment in the Vapor UI and click the "Rollback To" button, or you may use the rollback CLI command. The rollback command's "--select" option will allow you to select which deployment to rollback to from a list of recent deployments. If the rollback command is executed without this option, it will simply rollback to the most previous successful deployment:

vapor rollback production

vapor rollback production --select

# Deploying From CI

So far, we have discussed deploying Vapor projects from your local command line. However, you may also deploy them from a CI platform of your choice. Since the Vapor CLI client is part of your Composer dependencies, you may simply execute the vapor deploy command in your CI platform's deployment pipeline.

In order to authenticate with Vapor from your CI platform, you will need to add a VAPOR_API_TOKEN environment variable to your CI build environment. You may generate an API token in your Vapor API settings dashboard.

# Git Commit Information

Some CI platforms expose the Git commit information as environment variables during your build. You may pass this information to the vapor deploy command. For example, if using CodeShip:

vapor deploy production --commit="${CI_COMMIT_ID}" --message="${CI_MESSAGE}"