TSURU_SERVICES environment variable

tsuru exports an special environment variable in applications that use services, this variable is named TSURU_SERVICES. The value of this example is a JSON describing all services instances that the application uses. Here is an example of the value of this variable:

{
    "mysql": [
      {"instance_name": "mydb",
       "envs": {"DATABASE_NAME": "mydb",
                "DATABASE_USER": "mydb",
                "DATABASE_PASSWORD": "secret",
                "DATABASE_HOST": "mysql.mycompany.com"}
      },
      {"instance_name": "otherdb",
       "envs": {"DATABASE_NAME": "otherdb",
                "DATABASE_USER": "otherdb",
                "DATABASE_PASSWORD": "secret",
                "DATABASE_HOST": "mysql.mycompany.com"}
      }],
    "redis": [
      {"instance_name": "powerredis",
       "envs": {"REDIS_HOST": "remote.redis.company.com:6379"}
      }],
    "mongodb": []
}

As described in the structure, the value of the environment variable is a JSON object, where each key represents a service. In the example above, there are three services: mysql, redis and mongodb. Each service contains a list of service instances, and each instance have a name and a map of environment variables.