Syslog

Collect logs sent via Syslog

status: stable role: aggregator role: sidecar delivery: best effort acknowledgements: no egress: stream state: stateless output: log
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Configuration

Example configurations 

{
  "sources": {
    "my_source_id": {
      "type": "syslog",
      "address": "0.0.0.0:9000",
      "mode": "tcp",
      "path": "/path/to/socket"
    }
  }
}
[sources.my_source_id]
type = "syslog"
address = "0.0.0.0:9000"
mode = "tcp"
path = "/path/to/socket"

sources:
  my_source_id:
    type: syslog
    address: 0.0.0.0:9000
    mode: tcp
    path: /path/to/socket

{
  "sources": {
    "my_source_id": {
      "type": "syslog",
      "address": "0.0.0.0:9000",
      "max_length": 102400,
      "mode": "tcp",
      "path": "/path/to/socket"
    }
  }
}
[sources.my_source_id]
type = "syslog"
address = "0.0.0.0:9000"
max_length = 102_400
mode = "tcp"
path = "/path/to/socket"

sources:
  my_source_id:
    type: syslog
    address: 0.0.0.0:9000
    max_length: 102400
    mode: tcp
    path: /path/to/socket

address

required string literal

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

If a socket address is used, it must include a port.

Examples 
"0.0.0.0:9000"
"systemd"
"systemd#3"
Relevant when: mode = "tcp" or mode = "udp"

connection_limit

optional uint
The maximum number of TCP connections that are allowed at any given time.
Relevant when: mode = "tcp"

host_key

optional string literal

Overrides the name of the log field used to add the peer host to each event.

If using TCP or UDP, the value is the peer host’s address, including the port. For example, 1.2.3.4:9000. If using UDS, the value is the socket path itself.

By default, the global log_schema.host_key option is used.

keepalive

optional object
TCP keepalive settings for socket-based components.

keepalive.time_secs

optional uint
The time to wait before starting to send TCP keepalive probes on an idle connection.
Relevant when: mode = "tcp"

max_length

optional uint

The maximum buffer size of incoming messages, in bytes.

Messages larger than this are truncated.

default: 102400 (bytes)

mode

required string literal enum
The type of socket to use.
Examples 
"tcp"
"udp"
"unix"
Enum options string literal
OptionDescription
tcpListen on TCP.
udpListen on UDP.
unixListen on UDS. (Unix domain socket)

path

required string literal

The Unix socket path.

This should be an absolute path.

Examples 
"/path/to/socket"
Relevant when: mode = "unix"

receive_buffer_bytes

optional uint

The size of the receive buffer used for each connection.

This should not typically needed to be changed.

Relevant when: mode = "tcp" or mode = "udp"

socket_file_mode

optional uint

Unix file mode bits to be applied to the unix socket file as its designated file permissions.

The file mode value can be specified in any numeric format supported by your configuration language, but it is most intuitive to use an octal number.

Relevant when: mode = "unix"

tls

optional object
TlsEnableableConfig for sources, adding metadata from the client certificate.

tls.alpn_protocols

optional [string]

Sets the list of supported ALPN protocols.

Declare the supported ALPN protocols, which are used during negotiation with peer. They are prioritized in the order that they are defined.

tls.ca_file

optional string literal

Absolute path to an additional CA certificate file.

The certificate must be in the DER or PEM (X.509) format. Additionally, the certificate can be provided as an inline string in PEM format.

Examples 
"/path/to/certificate_authority.crt"

tls.client_metadata_key

optional string literal
Event field for client certificate metadata.

tls.crt_file

optional string literal

Absolute path to a certificate file used to identify this server.

The certificate must be in DER, PEM (X.509), or PKCS#12 format. Additionally, the certificate can be provided as an inline string in PEM format.

If this is set, and is not a PKCS#12 archive, key_file must also be set.

Examples 
"/path/to/host_certificate.crt"

tls.enabled

optional bool

Whether or not to require TLS for incoming or outgoing connections.

When enabled and used for incoming connections, an identity certificate is also required. See tls.crt_file for more information.

tls.key_file

optional string literal

Absolute path to a private key file used to identify this server.

The key must be in DER or PEM (PKCS#8) format. Additionally, the key can be provided as an inline string in PEM format.

Examples 
"/path/to/host_certificate.key"

tls.key_pass

optional string literal

Passphrase used to unlock the encrypted key file.

This has no effect unless key_file is set.

Examples 
"${KEY_PASS_ENV_VAR}"
"PassWord1"

tls.verify_certificate

optional bool

Enables certificate verification.

If enabled, certificates must not be expired and must be issued by a trusted issuer. This verification operates in a hierarchical manner, checking that the leaf certificate (the certificate presented by the client/server) is not only valid, but that the issuer of that certificate is also valid, and so on until the verification process reaches a root certificate.

Relevant for both incoming and outgoing connections.

Do NOT set this to false unless you understand the risks of not verifying the validity of certificates.

tls.verify_hostname

optional bool

Enables hostname verification.

If enabled, the hostname used to connect to the remote host must be present in the TLS certificate presented by the remote host, either as the Common Name or as an entry in the Subject Alternative Name extension.

Only relevant for outgoing connections.

Do NOT set this to false unless you understand the risks of not verifying the remote hostname.

Relevant when: mode = "tcp"

Outputs

<component_id>

Default output stream of the component. Use this component’s ID as an input to downstream transforms and sinks.

Output Data

Logs

Warning

The fields shown below will be different if log namespacing is enabled. See Log Namespacing for more details

Line

An individual Syslog event
Fields
* required string literal
In addition to the defined fields, any Syslog 5424 structured fields are parsed and inserted, namespaced under the name of each structured data section.
Examples
hello world
appname required string literal
The appname extracted from the Syslog formatted line. If a appname is not found, then the key will not be added.
Examples
app-name
client_metadata optional object
Client TLS metadata.
facility required string literal
The facility extracted from the Syslog line. If a facility is not found, then the key will not be added.
Examples
1
host required string literal
Same as hostname if that field is set, or the IP address of the peer otherwise.
Examples
my.host.com
127.0.0.1
hostname required string literal
The hostname field extracted from the Syslog line. If a hostname field is found, host is also set to this value.
Examples
my.host.com
message required string literal
The message extracted from the Syslog line.
Examples
Hello world
msgid required string literal
The msgid extracted from the Syslog line. If a msgid is not found, then the key will not be added.
Examples
ID47
procid required string literal
The procid extracted from the Syslog line. If a procid is not found, then the key will not be added.
Examples
8710
severity required string literal
The severity extracted from the Syslog line. If a severity is not found, then the key will not be added.
Examples
notice
source_ip required string literal
The IP address of the client. In the case where mode = "unix" the socket path will be used.
Examples
127.0.0.1
source_type required string literal
The name of the source type.
Examples
syslog
timestamp required timestamp
The time extracted from the Syslog formatted line. If parsing fails, then the exact time the event was ingested into Vector is used.
Examples
2020-10-10T17:07:36.452332Z
version required uint
The version extracted from the Syslog line. If a version is not found, then the key will not be added.
Examples
1

Telemetry

Metrics

link

component_discarded_events_total

counter
The number of events dropped by this component.
component_id
The Vector component ID.
component_kind
The Vector component kind.
component_type
The Vector component type.
host optional
The hostname of the system Vector is running on.
intentional
True if the events were discarded intentionally, like a filter transform, or false if due to an error.
pid optional
The process ID of the Vector instance.

component_errors_total

counter
The total number of errors encountered by this component.
component_id
The Vector component ID.
component_kind
The Vector component kind.
component_type
The Vector component type.
error_type
The type of the error
host optional
The hostname of the system Vector is running on.
pid optional
The process ID of the Vector instance.
stage
The stage within the component at which the error occurred.

component_received_bytes_total

counter
The number of raw bytes accepted by this component from source origins.
component_id
The Vector component ID.
component_kind
The Vector component kind.
component_type
The Vector component type.
container_name optional
The name of the container from which the data originated.
file optional
The file from which the data originated.
host optional
The hostname of the system Vector is running on.
mode optional
The connection mode used by the component.
peer_addr optional
The IP from which the data originated.
peer_path optional
The pathname from which the data originated.
pid optional
The process ID of the Vector instance.
pod_name optional
The name of the pod from which the data originated.
uri optional
The sanitized URI from which the data originated.

component_received_event_bytes_total

counter
The number of event bytes accepted by this component either from tagged origins like file and uri, or cumulatively from other origins.
component_id
The Vector component ID.
component_kind
The Vector component kind.
component_type
The Vector component type.
container_name optional
The name of the container from which the data originated.
file optional
The file from which the data originated.
host optional
The hostname of the system Vector is running on.
mode optional
The connection mode used by the component.
peer_addr optional
The IP from which the data originated.
peer_path optional
The pathname from which the data originated.
pid optional
The process ID of the Vector instance.
pod_name optional
The name of the pod from which the data originated.
uri optional
The sanitized URI from which the data originated.

component_received_events_count

histogram

A histogram of the number of events passed in each internal batch in Vector’s internal topology.

Note that this is separate than sink-level batching. It is mostly useful for low level debugging performance issues in Vector due to small internal batches.

component_id
The Vector component ID.
component_kind
The Vector component kind.
component_type
The Vector component type.
container_name optional
The name of the container from which the data originated.
file optional
The file from which the data originated.
host optional
The hostname of the system Vector is running on.
mode optional
The connection mode used by the component.
peer_addr optional
The IP from which the data originated.
peer_path optional
The pathname from which the data originated.
pid optional
The process ID of the Vector instance.
pod_name optional
The name of the pod from which the data originated.
uri optional
The sanitized URI from which the data originated.

component_received_events_total

counter
The number of events accepted by this component either from tagged origins like file and uri, or cumulatively from other origins.
component_id
The Vector component ID.
component_kind
The Vector component kind.
component_type
The Vector component type.
container_name optional
The name of the container from which the data originated.
file optional
The file from which the data originated.
host optional
The hostname of the system Vector is running on.
mode optional
The connection mode used by the component.
peer_addr optional
The IP from which the data originated.
peer_path optional
The pathname from which the data originated.
pid optional
The process ID of the Vector instance.
pod_name optional
The name of the pod from which the data originated.
uri optional
The sanitized URI from which the data originated.

component_sent_event_bytes_total

counter
The total number of event bytes emitted by this component.
component_id
The Vector component ID.
component_kind
The Vector component kind.
component_type
The Vector component type.
host optional
The hostname of the system Vector is running on.
output optional
The specific output of the component.
pid optional
The process ID of the Vector instance.

component_sent_events_total

counter
The total number of events emitted by this component.
component_id
The Vector component ID.
component_kind
The Vector component kind.
component_type
The Vector component type.
host optional
The hostname of the system Vector is running on.
output optional
The specific output of the component.
pid optional
The process ID of the Vector instance.

connection_read_errors_total

counter
The total number of errors reading datagram.
component_id
The Vector component ID.
component_kind
The Vector component kind.
component_type
The Vector component type.
host optional
The hostname of the system Vector is running on.
mode
pid optional
The process ID of the Vector instance.

source_lag_time_seconds

histogram
The difference between the timestamp recorded in each event and the time when it was ingested, expressed as fractional seconds.
component_id
The Vector component ID.
component_kind
The Vector component kind.
component_type
The Vector component type.
host optional
The hostname of the system Vector is running on.
pid optional
The process ID of the Vector instance.

utf8_convert_errors_total

counter
The total number of errors converting bytes to a UTF-8 string in UDP mode.
component_id
The Vector component ID.
component_kind
The Vector component kind.
component_type
The Vector component type.
host optional
The hostname of the system Vector is running on.
mode
The connection mode used by the component.
pid optional
The process ID of the Vector instance.

Examples

Syslog Event

Given this event...
<13>1 2020-03-13T20:45:38.119Z dynamicwireless.name non 2426 ID931 [exampleSDID@32473 iut="3" eventSource="Application" eventID="1011"] Try to override the THX port, maybe it will reboot the neural interface!
...and this configuration...
sources:
  my_source_id:
    type: syslog

[sources.my_source_id]
type = "syslog"

{
  "sources": {
    "my_source_id": {
      "type": "syslog"
    }
  }
}
...this Vector event is produced:
{
  "appname": "non",
  "exampleSDID@32473": {
    "eventID": "1011",
    "eventSource": "Application",
    "iut": "3"
  },
  "facility": "user",
  "host": "my-host.local",
  "hostname": "dynamicwireless.name",
  "message": "Try to override the THX port, maybe it will reboot the neural interface!",
  "msgid": "ID931",
  "procid": "2426",
  "severity": "notice",
  "source_ip": "34.33.222.212",
  "source_type": "syslog",
  "timestamp": "2020-03-13T20:45:38.119Z"
}

How it works

Context

By default, the syslog source augments events with helpful context keys.

Line Delimiters

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

Parsing

Vector makes a best effort to parse the various Syslog formats out in the wild. This includes RFC 6587, RFC 5424, RFC 3164, and other common variations (such as the Nginx Syslog style). It’s unfortunate that the Syslog specification isn’t more accurately followed, but we hope that Vector insulates you from these deviations.

If parsing fails, Vector will raise an error. If you find this happening often, we recommend using the socket source combined with regex parsing to implement your own custom ingestion and parsing scheme, or syslog parsing and manually handle any errors. Alternatively, you can open an issue to request support for your specific format.

State

This component is stateless, meaning its behavior is consistent across each input.

Transport Layer Security (TLS)

Vector uses OpenSSL for TLS protocols due to OpenSSL’s maturity. You can enable and adjust TLS behavior via the tls.* options and/or via an OpenSSL configuration file. The file location defaults to /usr/local/ssl/openssl.cnf or can be specified with the OPENSSL_CONF environment variable.
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