Syslog Source

The Vector syslog source ingests data through the Syslog 5424 protocol and outputs log events.

Configuration

• Common
• Advanced

vector.toml

[sources.my_source_id]
  # REQUIRED - General
  type = "syslog" # must be: "syslog"
  mode = "tcp" # example, enum
  # OPTIONAL - Context
  host_key = "host" # default
  # OPTIONAL - General
  address = "0.0.0.0:9000" # example, no default, relevant when mode = "tcp" or mode = "udp"
  path = "/path/to/socket" # example, no default, relevant when mode = "unix"

Options

5 items

common onlyrequired only

commonstringoptional

address

The TCP or UDP address to listen for connections on, or "systemd#N" to use the Nth socket passed by systemd socket activation.

No default

Only relevant when: mode = ["tcp","udp"]

View examples

commonstringrequired

host_key

The key name added to each event representing the current host. See Context for more info.

Default: "host"

View examples

intbytesoptional

max_length

The maximum bytes size of incoming messages before they are discarded.

Default: 102400

View examples

commonstringenumrequired

mode

The input mode.

No default

Enum, must be one of: "tcp" "udp" "unix"

View examples

commonstringoptional

path

The unix socket path. This should be absolute path.

No default

Only relevant when: mode = "unix"

View examples

Output

The syslog source ingests data through the Syslog 5424 protocol and outputs log events. For example:

{
  "appname": "app-name",
  "facility": "1",
  "host": "my.host.com",
  "message": "<13>Feb 13 20:07:26 74794bfb6795 root[8539]: i am foobar",
  "msgid": "ID47",
  "procid": 8710,
  "severity": "notice",
  "timestamp": "2019-11-01T21:15:47+00:00",
  "version": 1
}

More detail on the output schema is below.

9 items

required only

stringoptional

appname

The appname extracted from the Syslog 5424 line. If a appname is not found, then the key will not be added.

No default

View examples

stringoptional

facility

The facility extracted from the Syslog 5424 line. If a facility is not found, then the key will not be added.

No default

View examples

stringrequired

host

The hostname extracted from the Syslog 5424 line. If a hostname is not found, then Vector will use the upstream hostname. In the case where mode = "unix" the socket path will be used.

No default

View examples

stringrequired

message

The raw message, unaltered.

No default

View examples

stringoptional

msgid

The msgid extracted from the Syslog 5424 line. If a msgid is not found, then the key will not be added.

No default

View examples

intoptional

procid

The procid extracted from the Syslog 5424 line. If a procid is not found, then the key will not be added.

No default

View examples

stringoptional

severity

The severity extracted from the Syslog 5424 line. If a severity is not found, then the key will not be added.

No default

View examples

timestamprequired

timestamp

The timestamp extracted from the incoming line. If a timestamp is not found, then Vector will use the current time.

No default

View examples

intoptional

version

The version extracted from the Syslog 5424 line. If a version is not found, then the key will not be added.

No default

View examples

How It Works

Context

By default, the syslog source will add context keys to your events via the host_key options.

Environment Variables

Environment variables are supported through all of Vector's configuration. Simply add ${MY_ENV_VAR} in your Vector configuration file and the variable will be replaced before being evaluated.

You can learn more in the Environment Variables section.

Line Delimiters

Each line is read until a new line delimiter (the 0xA byte) is found.

Parsing

Vector will only parse messages in the Syslog 5424 format, Vector will not parse the Syslog 3164 format since 3164 is not an exact specification, but an observation of behavior.

Vector makes a best effort to parse the Syslog 5424 format. If parsing fails, the event will be dropped and warning log line will be emitted. If this is the case, we recommend using the socket source combined with the regex_parser transform to implement your own ingestion and parsing scheme.