config for Monolog for Symfony2/Symfony3

config_dev.yml

monolog:
    handlers:
        main:
            type:   stream
            path:   "%kernel.logs_dir%/%kernel.environment%.log"
            level:  debug
        console:
            type:   console
            bubble: false

config_prod.yml

monolog:
    handlers:
        main:
            type:         fingers_crossed
            action_level: error
            handler:      main_grouped
            channels:     ["!doctrine","!security"]
            excluded_404s:
                - ^/$
                - ^/vtigercrm/
        main_grouped:
            type:    group
            members: [nested, swift]
            formatter: monolog.formatter.session_request
        nested:
            type:  stream
            path:  "%kernel.logs_dir%/%kernel.environment%.main.log"
            level: debug
            formatter: monolog.formatter.session_request

        doctrine:
            type:         fingers_crossed
            action_level: error
            handler:      doctrine_grouped
            channels:     [doctrine]
        doctrine_grouped:
            type:    group
            members: [doctrine_nested, swift]
        doctrine_nested:
            type:  stream
            path:  "%kernel.logs_dir%/%kernel.environment%.doctrine.log"
            level: debug

        swift:
            type:               swift_mailer
            from_email:         "%monolog.email.from%"
            to_email:           "%monolog.email.to%"
            subject:            "%monolog.email.subject%"
            level:              debug

        login:
            type:     stream
            path:     "%kernel.logs_dir%/%kernel.environment%.login.log"
            level:    info
            channels: [security]

        console:
            type:  console