telegraf/plugins/inputs/syslog

syslog input plugin

Collects syslog messages as per RFC5425 or RFC5426.

It can act as a syslog transport receiver over TLS (or TCP) - ie., RFC5425 - or over UDP - ie., RFC5426.

This plugin listens for syslog messages following RFC5424 format. When received it parses them extracting metrics.

Configuration

[[inputs.syslog]]
  ## Specify an ip or hostname with port - eg., tcp://localhost:6514, tcp://10.0.0.1:6514
  ## Protocol, address and port to host the syslog receiver.
  ## If no host is specified, then localhost is used.
  ## If no port is specified, 6514 is used (RFC5425#section-4.1).
  server = "tcp://:6514"

  ## TLS Config
  # tls_allowed_cacerts = ["/etc/telegraf/ca.pem"]
  # tls_cert = "/etc/telegraf/cert.pem"
  # tls_key = "/etc/telegraf/key.pem"

  ## Period between keep alive probes.
  ## 0 disables keep alive probes.
  ## Defaults to the OS configuration.
  ## Only applies to stream sockets (e.g. TCP).
  # keep_alive_period = "5m"

  ## Maximum number of concurrent connections (default = 0).
  ## 0 means unlimited.
  ## Only applies to stream sockets (e.g. TCP).
  # max_connections = 1024

  ## Read timeout (default = 500ms).
  ## 0 means unlimited.
  # read_timeout = 500ms

  ## Whether to parse in best effort mode or not (default = false).
  ## By default best effort parsing is off.
  # best_effort = false

  ## Character to prepend to SD-PARAMs (default = "_").
  ## A syslog message can contain multiple parameters and multiple identifiers within structured data section.
  ## Eg., [id1 name1="val1" name2="val2"][id2 name1="val1" nameA="valA"]
  ## For each combination a field is created.
  ## Its name is created concatenating identifier, sdparam_separator, and parameter name.
  # sdparam_separator = "_"

Other configs

Other available configurations are:

• keep_alive_period, max_connections for stream sockets
• read_timeout
• best_effort to tell the parser to work until it is able to do and extract partial but valid info (more here)
• sdparam_separator to choose how to separate structured data param name from its structured data identifier

Metrics

• syslog
  • fields
    • version (uint16)
    • severity_code (int)
    • facility_code (int)
    • timestamp (int)
    • procid (string)
    • msgid (string)
    • sdid (bool)
    • sdid . sdparam_separator . sdparam_name (string)
  • tags
    • severity (string)
    • facility (string)
    • hostname (string)
    • appname (string)

The name of fields in italic corresponds to their runtime value.

The fields/tags which name is in bold will always be present when a valid Syslog message has been received.

RSYSLOG integration

The following instructions illustrate how to configure a syslog transport sender as per RFC5425 - ie., using the octect framing technique - via RSYSLOG.

Install rsyslog.

Give it a configuration - ie., /etc/rsyslog.conf.

$ModLoad imuxsock  # provides support for local system logging
$ModLoad imklog    # provides kernel logging support
$ModLoad immark    # provides heart-beat logs
$FileOwner root
$FileGroup root
$FileCreateMode 0640
$DirCreateMode 0755
$Umask 0022
$WorkDirectory /var/spool/rsyslog # default location for work (spool) files
$ActionQueueType LinkedList # use asynchronous processing
$ActionQueueFileName srvrfwd # set file name, also enables disk mode
$ActionResumeRetryCount -1 # infinite retries on insert failure
$ActionQueueSaveOnShutdown on # save in-memory data if rsyslog shuts down
$IncludeConfig /etc/rsyslog.d/*.conf

Specify you want the octet framing technique enabled and the format of each syslog message to follow the RFC5424.

Create a file - eg., /etc/rsyslog.d/50-default.conf - containing:

*.* @@(o)127.0.0.1:6514;RSYSLOG_SyslogProtocol23Format

To complete the TLS setup please refer to rsyslog docs.

Notice that this configuration tells rsyslog to broadcast messages to 127.0.0.1>6514.

So you have to configure this plugin accordingly.