# Configure logging drivers The container can have a different logging driver than the Docker daemon. Use the `--log-driver=VALUE` with the `docker run` command to configure the container's logging driver. The following options are supported: | `none` | Disables any logging for the container. `docker logs` won't be available with this driver. | |-------------|-------------------------------------------------------------------------------------------------------------------------------| | `json-file` | Default logging driver for Docker. Writes JSON messages to file. | | `syslog` | Syslog logging driver for Docker. Writes log messages to syslog. | | `journald` | Journald logging driver for Docker. Writes log messages to `journald`. | | `gelf` | Graylog Extended Log Format (GELF) logging driver for Docker. Writes log messages to a GELF endpoint likeGraylog or Logstash. | | `fluentd` | Fluentd logging driver for Docker. Writes log messages to `fluentd` (forward input). | The `docker logs`command is available only for the `json-file` logging driver. ### The json-file options The following logging options are supported for the `json-file` logging driver: --log-opt max-size=[0-9+][k|m|g] --log-opt max-file=[0-9+] Logs that reach `max-size` are rolled over. You can set the size in kilobytes(k), megabytes(m), or gigabytes(g). eg `--log-opt max-size=50m`. If `max-size` is not set, then logs are not rolled over. `max-file` specifies the maximum number of files that a log is rolled over before being discarded. eg `--log-opt max-file=100`. If `max-size` is not set, then `max-file` is not honored. If `max-size` and `max-file` are set, `docker logs` only returns the log lines from the newest log file. ### The syslog options The following logging options are supported for the `syslog` logging driver: --log-opt syslog-address=[tcp|udp]://host:port --log-opt syslog-address=unix://path --log-opt syslog-facility=daemon --log-opt syslog-tag="mailer" `syslog-address` specifies the remote syslog server address where the driver connects to. If not specified it defaults to the local unix socket of the running system. If transport is either `tcp` or `udp` and `port` is not specified it defaults to `514` The following example shows how to have the `syslog` driver connect to a `syslog` remote server at `192.168.0.42` on port `123` $ docker run --log-driver=syslog --log-opt syslog-address=tcp://192.168.0.42:123 The `syslog-facility` option configures the syslog facility. By default, the system uses the `daemon` value. To override this behavior, you can provide an integer of 0 to 23 or any of the following named facilities: * `kern` * `user` * `mail` * `daemon` * `auth` * `syslog` * `lpr` * `news` * `uucp` * `cron` * `authpriv` * `ftp` * `local0` * `local1` * `local2` * `local3` * `local4` * `local5` * `local6` * `local7` The `syslog-tag` specifies a tag that identifies the container's syslog messages. By default, the system uses the first 12 characters of the container id. To override this behavior, specify a `syslog-tag` option ## Specify journald options The `journald` logging driver stores the container id in the journal's `CONTAINER_ID` field. For detailed information on working with this logging driver, see [the journald logging driver](/reference/logging/journald/) reference documentation. ## Specify gelf options The GELF logging driver supports the following options: --log-opt gelf-address=udp://host:port --log-opt gelf-tag="database" The `gelf-address` option specifies the remote GELF server address that the driver connects to. Currently, only `udp` is supported as the transport and you must specify a `port` value. The following example shows how to connect the `gelf` driver to a GELF remote server at `192.168.0.42` on port `12201` $ docker run --log-driver=gelf --log-opt gelf-address=udp://192.168.0.42:12201 The `gelf-tag` option specifies a tag for easy container identification. ## Specify fluentd options You can use the `--log-opt NAME=VALUE` flag to specify these additional Fluentd logging driver options. - `fluentd-address`: specify `host:port` to connect [localhost:24224] - `fluentd-tag`: specify tag for `fluentd` message, When specifying a `fluentd-tag` value, you can use the following markup tags: - `{{.ID}}`: short container id (12 characters) - `{{.FullID}}`: full container id - `{{.Name}}`: container name For example, to specify both additional options: `docker run --log-driver=fluentd --log-opt fluentd-address=localhost:24224 --log-opt fluentd-tag=docker.{{.Name}}` If container cannot connect to the Fluentd daemon on the specified address, the container stops immediately. For detailed information on working with this logging driver, see [the fluentd logging driver](/reference/logging/fluentd/)