deployer

Deployer refers to two related concepts in software engineering: a person who performs software deployment and a software tool used to automate deployments. In this sense, a deployer is responsible for planning releases, packaging builds, provisioning environments, coordinating with development, operations, and QA teams, executing deployment steps, and validating a release in production. Post-deployment tasks such as verifying service availability and initiating post-deployment tests may also fall under the deployer's responsibilities.

In the context of tools, Deployer is a widely used open-source deployment tool for PHP projects. It automates the process of deploying code to one or more remote servers over SSH, using a configuration file (deploy.php) and framework-specific recipes to define tasks. Deployments typically create a new release directory, install dependencies, update the current symlink to point to the new release, and manage shared resources and file permissions.

Key concepts in Deployer include hosts with roles, releases directories, shared files, and the current symlink. It supports task orchestration, hooks before and after steps, and rollback by re-pointing the current symlink to a previous release. It can run tasks in sequence or in parallel and provides dry-run options for testing deployments. Framework-specific recipes exist for Laravel, Symfony, Drupal, and generic PHP projects.

Use of the tool helps ensure repeatability, auditable deployments, and faster recovery, but requires SSH access to servers and some initial setup to define environments and permissions. Deployer is commonly used in the PHP ecosystem and is part of the broader practice of automation in DevOps and continuous delivery.