在Symfony 2.8中使用现有环境变量

Question

I have an application built using Symfony 2.8. Now, the application config need to access an environment variable. This is not working in Symfony 2.8 (config.yml),

id: "%env(SOME_ID)%"

Is there a way to access it in config.yml file.

Answer 1

With Symfony 2.8, you can declare some external parameters from your server :

• With Apache, with the SetEnv directive:

  <VirtualHost *:80>
      ...
      SetEnv    SYMFONY__DATABASE__USER user
      SetEnv    SYMFONY__DATABASE__PASSWORD secret
      SetEnv    SYMFONY__SOME_ID 1234
      ...
  </VirtualHost>
  

• With Nginx, with fastcgi_param directive:

  server {
    ...
    location ~ ^/app\.php(/|$) {
      ...
      fastcgi_param SYMFONY__DATABASE__USER user;
      fastcgi_param SYMFONY__DATABASE__PASSWORD secret;
      fastcgi_param SYMFONY__SOME_ID 1234
      ...
    }
  }
  

These environment variables will be passed to the container, with some transformations:

• SYMFONY__ prefix is removed
• Parameter name is lowercased
• Double underscores __ are replaced with a period.

So you can use them as is:

doctrine:
    dbal:
    driver:   pdo_mysql
    dbname:   symfony_project
    user:     '%database.user%'
    password: '%database.password%'
some_config:
    id: '%some_id%'

You can also pass some PHP constants :

parameters:
    some_id: "@=constant('SOME_ID')"
    my_class.some_id: "@=constant('My_Class::SOME_ID')"

Hope that helps !