There are multiple problems with a typical approach to configuration:
In order to solve these issues Yii introduces a simple environments concept. Each environment is represented
by a set of files under the environments
directory. The init
command is used to initialize an environment. What it really does is
copy everything from the environment directory over to the root directory where all applications are.
By default there are two environments: dev
and prod
. First is for development. It has all the developer tools
and debug turned on. Second is for server deployments. It has debug and developer tools turned off.
Typically environment contains application bootstrap files such as index.php
and config files suffixed with
-local.php
. Local configs in environments
directory are templates that, after init
is executed,
are being copied into corresponding application config directories. After that, they become your local configuration.
They are meant to keep secret and environment-specific settings, such as database connection credentials,
and aren't meant to be put into version control system. Thus these files are added to .gitignore
so git is not
considering them for staging.
In order to avoid duplication configurations are overriding each other. For example, the frontend reads configuration in the following order:
common/config/main.php
common/config/main-local.php
frontend/config/main.php
frontend/config/main-local.php
Parameters are read in the following order:
common/config/params.php
common/config/params-local.php
frontend/config/params.php
frontend/config/params-local.php
The later config file overrides the former.
Here's the full scheme: