Apex offers hands free version control, as it will automatically keep track of all modifications made to your packages. Upgrades can be instantly published to their repository, from where they can be instantly installed on any systems with that package installed. Full rollback functionality is also supported, so in case an upgrade goes wrong, the individual system can be rolled back to its previous state before the upgrade.
After you have initially published your package, you will want to create an upgrade point on it. Within terminal, type:
./apex create_upgrade PACKAGE
This will create a new upgrade point on the package, plus scan all files within the package, and save their SHA1 hash. These hashes are used later when publishing the package to determine which files were modified.
After creating an upgrade point, a new directory will be created at /etc/PACKAGE/upgrades/VERSION. This directory contains a few pertinent files, which are explained below.
| File | Description |
|---|---|
| upgrade.php | Allows you to define PHP code to be executed upon installation / rollback of the upgrade. |
| install.sql | Any SQL code within this file is executed against the database upon installation of the upgrade. |
| rollback.sql | Any SQL code within this file is executed against the database if / when the upgrade is rolled back. |
Once you have completed development and testing of the upgrade, you will want to publish it to the repository, making it available to all systems that have the package installed. To publish an upgrade, within terminal type:
./apex publish_upgrade PACKAGE
It will compile the upgrade as necessary, and publish it to the repository where the package resides. The upgrade is now instantly available to all Apex systems with the package installed.
Installing upgrades couldn't be easier. If desired, you can always view a list of installed packages that have new upgrades available via the Maintenance->Package Manager menu of the administration panel. To install available upgrades, simply open up terminal and type:
./apex upgrade
It will simply download the appropriate upgrades from their respective repositories, and install them on the system.
If ever needed, upgrades can be easily rolled back on an individual system. Within terminal, simply type:
./apex rollback PACKAGE
You will be prompted to select which version you would like to rollback to. The system will then revert to the exact same codebase as before the upgrade was installed.