SQLSTATE[HY000] [2002] No such file or directory

Hi there

The error SQLSTATE[HY000] [2002] No such file or directory often occurs when your PHP application is trying to connect to a MySQL server via a Unix socket, but the socket file doesn’t exist at the specified location. When deploying to a DigitalOcean managed MySQL database, you will connect over the network (typically using a hostname and port), not a Unix socket.

When deploying applications, especially on platforms that use distinct build and deploy stages, it’s crucial to understand the appropriate time to establish database connections or perform database-related operations.

During the build stage, the primary goal is to compile, package, or prepare the application for deployment. Typically, this involves tasks like:

• Installing dependencies (e.g., composer install for PHP projects)
• Compiling source code, if applicable
• Minifying or bundling assets

Connecting to a database during the build stage is not recommended, as:

• The build environment might not have access to your production or staging databases for security reasons.
• You could inadvertently modify your database during the build process.
• The build stage should remain environment-agnostic. This means it should be identical whether you’re deploying to a staging, production, or any other environment.

During the deploy stage, the application is actually being launched and made ready for user traffic. This is the right time to:

• Establish connections to databases
• Run database migrations or schema updates
• Perform any final configurations that are environment-specific

Given that you’re facing the SQLSTATE[HY000] [2002] No such file or directory error during the build stage after composer install, it seems like there might be a post-install script or some logic that’s attempting to connect to the database.

1. Check composer.json: Look in the scripts section of your composer.json file. Ensure there aren’t any post-install or post-update scripts that are trying to connect to the database or run Symfony commands that require a database connection.

2. Move Database-related Operations: If there are any, consider moving them to a deployment script or another mechanism that runs during the deploy stage. Remember, the build stage should only prepare the code and assets, not interact with external services.

3. Environment Variables: Make sure your application knows when it’s in build mode vs. deploy mode. This way, even if there’s code that tries to connect to the database, you can prevent it from executing during the build stage.

Let me know how it goes!

Best,

Bobby