Environment configuration as provided by Symfony was enhanced as of eZ Publish 5.2 and eZ Publish Community Project 2013.06 to allow specifying this in the virtual host configuration.
You can configure several environments, from production, development or staging, even if for each one of them you need require using different configurations sets.

Web server configuration

For example, using apache, in the VirtualHost example in the Virtual host setup chapter the required VirtualHost configurations have been already included. You can switch to the desired environment by setting the ENVIRONMENT environment variable to "prod", "dev" or other custom value, as you can see in the following example:

    # Environment.
    # Possible values: "prod" and "dev" out-of-the-box, other values possible with proper configuration (described below)
    # Defaults to "prod" if omitted
    SetEnv ENVIRONMENT "prod"

eZ Publish Configuration

If you want to use a custom environment (something else then "prod" and "dev") the next step is to create the dedicated configuration files for your environment:

• ezpublish/config/config_<env_name>.yml
• ezpublish/config/ezpublish_<env_name>.yml

The name used as <env_name> will be the one that can be used as value of the ENVIRONMENT environment variable.

Those files must import the main configuration file, just like the default config_dev.yml already does. Here's an example:

imports:
    - { resource: config.yml }

This allows you to override settings defined in the main configuration file, depending on your environment (like the DB settings or any other setting you may want to override).