Small syslog server written in Java. Useful for testing, small installations or for forwarding messages to other logging solutions. Accepts RFC-3164 (BSD), RFC-5424 and GELF log messages on a configurable port, UDP and/or TCP. https://github.com/mnellemann/syslogd
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README.md

Syslog Director

All received messages are written to stdout and/or forwarded to remote logging destinations.

Supported incoming message formats are:

  • Syslog RFC5424 - TCP and UDP
  • Syslog RFC3164 (BSD) - TCP and UDP
  • Graylog GELF - TCP and UDP (compressed & chunked)

Supported remote logging destinations are:

  • Syslog (RFC5424 over UDP)
  • Graylog (GELF over UDP)
  • Grafana Loki (HTTP over TCP).

This software is free to use and is licensed under the Apache 2.0 License.

architecture

Some of my other related projects are:

  • hmci for agent-less monitoring of IBM Power servers
  • svci for monitoring IBM Spectrum Virtualize (Flashsystems / Storwize / SVC)
  • sysmon for monitoring all types of servers with a small Java agent

Usage Instructions

  • Install the syslogd package (.deb or .rpm) from packages or build from source.
Usage: syslogd [-dhV] [--[no-]ansi] [--[no-]stdin] [--[no-]stdout] [--[no-]tcp]
               [--[no-]udp] [-f=<protocol>] [-p=<num>] [--to-gelf=<uri>]
               [--to-loki=<url>] [--to-syslog=<uri>]
  -d, --debug               Enable debugging [default: 'false'].
  -f, --format=<protocol>   Input format: RFC-5424, RFC-3164 or GELF [default:
                              RFC-3164].
  -h, --help                Show this help message and exit.
      --[no-]ansi           Output in ANSI colors [default: true].
      --[no-]stdin          Forward messages from stdin [default: true].
      --[no-]stdout         Output messages to stdout [default: true].
      --[no-]tcp            Listen on TCP [default: true].
      --[no-]udp            Listen on UDP [default: true].
  -p, --port=<num>          Listening port [default: 1514].
      --to-gelf=<uri>       Forward to Graylog <udp://host:port>.
      --to-loki=<url>       Forward to Grafana Loki <http://host:port>.
      --to-syslog=<uri>     Forward to Syslog <udp://host:port> (RFC-5424).
  -V, --version             Print version information and exit.

The default syslog port (514) requires you to run syslogd as root / administrator. Any port number above 1024 does not require privileges and can be selected with the -p or --port option.

Examples

Listening on the default syslog port:

java -jar /path/to/syslogd-x.y.z-all.jar --port 514

or, if installed as a deb or rpm package:

/opt/syslogd/bin/syslogd --port 514

Forwarding messages on to another log-system on a non-standard port.

java -jar /path/to/syslogd-x.y.z-all.jar --to-syslog udp://remotehost:514

Forwarding messages to a Graylog server in GELF format.

java -jar /path/to/syslogd-x.y.z-all.jar --to-gelf udp://remotehost:12201

Forwarding to a Grafana Loki server.

java -jar /path/to/syslogd-x.y.z-all.jar --to-loki http://remotehost:3100

If you don't want any output locally (only forwarding), you can use the --no-stdout flag.

Notes

IBM AIX and VIO Servers

Syslog messages from AIX (and IBM Power Virtual I/O Servers) can be troublesome with some logging solutions. These can be received with syslogd and then forwarded on to your preferred logging solution.

Forwarding to Grafana Loki

Forwarding is currently done by making HTTP connections to the Loki API, which works fine for low volume messages, but might cause issues for large volume of messages.

Development Notes

Test Grafana Loki

Run Loki and Grafana in local containers to test.

docker run --rm -d --name=loki -p 3100:3100 grafana/loki
docker run --rm -d --name=grafana --link loki:loki -p 3000:3000 grafana/grafana:7.1.3