[Windows/Linux/Mac][PHP Deployer] Zero Downtime PHP Deployment

Deployer – https://deployer.org/
A zero downtime PHP deployment tool.

How it works?

Basically it SSH into the remote server, git clone to new folder, composer install, and create symlink to latest release folder
And optionally run database migration, restart PHP-FPM. If either step fails, it rollbacks the whole transaction.

Requirements:

Linux/Mac/Windows (Under bash)
Composer
Password-less SSH access to remote server
Project hosted on Git, clone-able via SSH (No matter public/private repository)

Installation:

1. Install deployer
   Aside from official installation method, I recommend installing it by composer
   composer global require deployer/deployer
   Then add ~/.config/composer/vendor/bin (Mac/Linux)
   or %HOME%\AppData\Roaming\Composer\vendor\bin (Windows) to your environment path
   After finish, try to run dep -V to see if it installed correctly.
2. Prepare deploy.php script
   deployer is configured using a PHP script (deploy.php) under your project root.
   So now cd to your project root and run dep init
Select if you use any framework, otherwise “Common”, and enter the address of your git repository
3. Edit deploy.php
   Change the host and path of your server

   host('project.com')
       ->stage('production')
       ->set('deploy_path', '/var/www/project.com');

4.  Disable git_tty and ssh_multiplexing (Windows bash only)
   ssh_multiplexing speed up deployment a lot, but for some reason it does not work on Windows Bash environment.
   So we must disable it to make it works under Windows, add this

   // Windows Compatibility
   if (strtoupper(substr(PHP_OS, 0, 3)) === 'WIN') {
       set('git_tty', false);
       set('ssh_multiplexing', false);
   }

5. Make sure all host keys are accepted
   1. ssh from LOCAL to REMOTE server at least once, and make sure the key is accepted
   2. Make sure your REMOTE server have the keypair to clone from git (If your repository is private)
   3. git clone on your REMOTE server at least once, and make sure the key is accepted
   Otherwise you likely encounter “Host key verification failed”
6. Run deployer
   dep deploy production -vvv
   production is the stage you specified in deploy.php
   -vvv flag show the most verbose output, useful to check if any error occurred during deployment.
7. Point your Apache/nginx to the symlink like /var/www/project.com/current
8. Read the doc for more options
   Reference: https://deployer.org/docs