How sources work

A source is where AxoSyslog receives log messages. Sources consist of one or more drivers, each defining where and how messages are received.

To define a source, add a source statement to the syslog-ng.conf configuration file using the following syntax:

Terminal window
   source <identifier> {
        source-driver(params); source-driver(params); ...
    };

Example: A simple source statement

The following source statement receives messages on the TCP port 1999 of the interface having the 10.1.2.3 IP address.

Terminal window
   source s_demo_tcp {
        network(ip(10.1.2.3) port(1999));
    };

Example: A source statement using two source drivers

The following source statement receives messages on the 1999 TCP port and the 1999 UDP port of the interface having the 10.1.2.3 IP address.

Terminal window
   source s_demo_two_drivers {
        network(ip(10.1.2.3) port(1999));
        network(ip(10.1.2.3) port(1999) transport("udp"));
    };

Example: Setting default priority and facility

If the message received by the source does not have a proper syslog header, you can use the default-facility() and default-priority() options to set the facility and priority of the messages. Note that these values are applied only to messages that do not set these parameters in their header.

Terminal window
   source headerless_messages { network(default-facility(syslog) default-priority(emerg)); };

Define a source only once. The same source can be used in several log paths. Duplicating sources causes AxoSyslog to open the source (TCP/IP port, file, and so on) more than once, which might cause problems. For example, include the /dev/log file source only in one source statement, and use this statement in more than one log path if needed.

To collect log messages on a specific platform, it is important to know how the native syslogd communicates on that platform. The following table summarizes the operation methods of syslogd on some of the tested platforms:

Communication methods used between the applications and syslogd

Platform Method
Linux A SOCK_DGRAM unix socket named /dev/log. Newer distributions that use systemd collect log messages into a journal file.
BSD flavors A SOCK_DGRAM unix socket named /var/run/log.
Solaris (2.5 or below) An SVR4 style STREAMS device named /dev/log.
Solaris (2.6 or above) In addition to the STREAMS device used in earlier versions, 2.6 uses a new multithreaded IPC method called door. By default the door used by syslogd is /etc/.syslog_door.
HP-UX 11 or later HP-UX uses a named pipe called /dev/log that is padded to 2048 bytes, for example, source s_hp-ux {pipe ("/dev/log" pad-size(2048)}.
AIX 5.2 and 5.3 A SOCK_STREAM or SOCK_DGRAM unix socket called /dev/log.

Each possible communication mechanism has a corresponding source driver in syslog-ng. For example, to open a unix socket with SOCK_DGRAM style communication use the driver unix-dgram. The same socket using the SOCK_STREAM style — as used under Linux — is called unix-stream.

Example: Source statement on a Linux based operating system

The following source statement collects the following log messages:

  • internal(): Messages generated by syslog-ng.

  • network(transport(“udp”)): Messages arriving to the 514/UDP port of any interface of the host.

  • unix-dgram("/dev/log");: Messages arriving to the /dev/log socket.

Terminal window
   source s_demo {
        internal();
        network(transport("udp"));
        unix-dgram("/dev/log");
    };

Sources list

Choose a network source

If your clients send… Use
BSD syslog (RFC3164) over TCP, UDP, or TLS network()
IETF syslog (RFC5424) over TCP, UDP, or TLS syslog()
Mixed syslog traffic that you want to receive and parse automatically default-network-drivers()
OpenTelemetry (OTLP/gRPC) from OpenTelemetry clients opentelemetry()
Logs from another AxoSyslog node axosyslog-otlp()
HTTP or HTTPS requests (webhooks) webhook() or webhook-json(), or ehttp()
Events for the Splunk HTTP Event Collector (for example, from SC4S) splunk-hec()
Data from Elastic Agent, Beats, or other Elasticsearch Bulk API clients elasticsearch-bulk()

The default-network-drivers() source needs @include "scl.conf" in your configuration file.

The following table lists the source drivers available in AxoSyslog.

Name Description
lidarr(), prowlarr(), radarr(), readarr(), sonarr(), whisparr() Collect logs of *arr media management applications
axosyslog-otlp() Receive logs from another node using OpenTelemetry
darwin-oslog(), darwin-oslog-stream() Collect native macOS system logs
default-network-drivers() Receive and parse common syslog messages
ehttp() Receive logs over HTTP or HTTPS
elasticsearch-bulk() Receive messages from clients of the Elasticsearch Bulk API
file() Collect messages from text files
hypr-audit-trail(), hypr-app-audit-trail() Fetch events from the Hypr REST API
internal() Collect internal messages
jellyfin() Collect Jellyfin logs
kubernetes() Collect and parse messages in the Kubernetes CRI (Container Runtime Interface) format
linux-audit() Collect messages from Linux audit logs
mbox() Convert local email messages to log messages
mqtt() Fetch messages from MQTT brokers
network() Collect messages using the RFC3164 protocol
nodejs() Receive JSON messages from nodejs applications
openbsd() Collect kernel log messages on OpenBSD systems
opentelemetry() Receive logs, metrics, and traces from OpenTelemetry clients over the OpenTelemetry Protocol (OTLP/gRPC)
osquery() Collect and parse osquery result logs
pacct() Collect process accounting logs on Linux
pihole-ftl() Collect Pi-hole FTL logs
pipe() Collect messages from named pipes
program() Receive messages from external applications
python() Server-style Python source that receives messages
python-fetcher() Write a fetcher-style Python source
qbittorrent() Collect qBittorrent logs
snmptrap() Read Net-SNMP traps
splunk-hec() Receive messages sent to the Splunk HTTP Event Collector (HEC)
stdin() Collect messages from the standard input stream
sun-streams() Collect messages on Sun Solaris
syslog() Collect messages using the IETF-syslog protocol
system() Collect the system-specific log messages of a platform
systemd-journal() Collect messages from the systemd-journal system log storage
systemd-syslog() Collect systemd messages using a socket
tcp(), tcp6(), udp(), udp6() OBSOLETE - Collect messages from remote hosts using the BSD syslog protocol
unix-stream(), unix-dgram() Collect messages from UNIX domain sockets
webhook(), webhook-json() Receive logs via a HTTP webhook
wildcard-file() Collect messages from multiple text files