Monolog handler configuration

monolog.yml

monolog:
    handlers:
        log_everything:
            type:         fingers_crossed
            action_level: critical
            handler:      grouped
            channels:     [!frontend, !deprecation]

        grouped:
            type:    group
            members: [database, buffered]

        buffered:
            type:    buffer
            handler: swift

        swift:
            type:       swift_mailer
            from_email: %mailer_error_from_email%
            to_email:   %mailer_error_to_email%
            subject:    %mailer_error_subject%
            level:      debug

        database:
            type: service
            id: monolog.handler.pdo
            level: debug

        cctrl_log:
            type: stream
            path: php://stderr
            level: warning