Upgrading from Deployer 3 to Deployer 4

If you are upgrading Deployer from version 3 to 4 you will see issues when trying to deploy, for example:

[ERROR] Error: Call to undefined function set() in /Users/stakhr/site/deploy.php:5    
       Stack trace:                                                                                
       #0 phar:///Users/stakhr/site/deployer.phar/bin/dep(114): require()            
       #1 phar:///Users/stakhr/site/deployer.phar/bin/dep(115): {closure}()          
       #2 /Users/stakhr/site/deployer.phar(4): require('phar:///Users/s...')         
       #3 {main}  

To fix these issues, you need to do a few things:

• Add a Deployer namespace declaration at the top of your deploy.php file, like this: namespace Deployer;
• The env() function has been deprecated. Replace it with set() when setting variables (two parameters) and get() when getting variables (one parameter)
• The underlying SSH implementation will be changed in Deployer 5, so add set('ssh_type', 'native'); to fix the nag that shows up.

Here is a full example of deploying a WordPress site using Deployer 4

PS. I’ve also noted that running deployer self-update on version 3 does not upgrade to version 4.