Fluent

Collect logs from a Fluentd or Fluent Bit agent

status: beta role: sidecar role: aggregator delivery: best effort acknowledgements: yes egress: stream state: stateless output: log
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Configuration

Example configurations 

{
  "sources": {
    "my_source_id": {
      "type": "fluent",
      "address": "0.0.0.0:9000"
    }
  }
}
[sources.my_source_id]
type = "fluent"
address = "0.0.0.0:9000"

sources:
  my_source_id:
    type: fluent
    address: 0.0.0.0:9000

{
  "sources": {
    "my_source_id": {
      "type": "fluent",
      "address": "0.0.0.0:9000",
      "permit_origin": [
        "192.168.0.0/16"
      ],
      "receive_buffer_bytes": 65536
    }
  }
}
[sources.my_source_id]
type = "fluent"
address = "0.0.0.0:9000"
permit_origin = [ "192.168.0.0/16" ]
receive_buffer_bytes = 65_536

sources:
  my_source_id:
    type: fluent
    address: 0.0.0.0:9000
    permit_origin:
      - 192.168.0.0/16
    receive_buffer_bytes: 65536

acknowledgements

optional object

Deprecated

This field is deprecated.

Controls how acknowledgements are handled by this source.

This setting is deprecated in favor of enabling acknowledgements at the global or sink level.

Enabling or disabling acknowledgements at the source level has no effect on acknowledgement behavior.

See End-to-end Acknowledgements for more information on how event acknowledgement is handled.

acknowledgements.enabled

optional bool
Whether or not end-to-end acknowledgements are enabled for this source.

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"

connection_limit

optional uint
The maximum number of TCP connections that are allowed at any given time.

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.

permit_origin

optional [string]
List of allowed origin IP networks. IP addresses must be in CIDR notation.
Array string literal
Examples 
[
  "192.168.0.0/16",
  "127.0.0.1/32",
  "::1/128",
  "9876:9ca3:99ab::23/128"
]

receive_buffer_bytes

optional uint

The size of the receive buffer used for each connection.

This generally should not need to be changed.

Examples 
65536

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.server_name

optional string literal

Server name to use when using Server Name Indication (SNI).

Only relevant for outgoing connections.

Examples 
"www.example.com"

tls.verify_certificate

optional bool

Enables certificate verification. For components that create a server, this requires that the client connections have a valid client certificate. For components that initiate requests, this validates that the upstream has a valid certificate.

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.

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.

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

A Fluent message
Fields
* required string literal
In addition to the defined fields, all fields from the fluent message are inserted as root level fields.
Examples
hello world
client_metadata optional object
Client TLS metadata.
host required string literal
The IP address the fluent message was sent from.
Examples
127.0.0.1
tag required string literal
The tag from the fluent message.
Examples
dummy.0
timestamp required timestamp
The timestamp extracted from the fluent message.
Examples
2020-10-10T17:07:36.452332Z

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.

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.

Examples

Dummy message from fluentd

Given this event...
2021-05-20 16:23:03.021497000 -0400 dummy: {"message":"dummy"}
...and this configuration...
sources:
  my_source_id:
    type: fluent

[sources.my_source_id]
type = "fluent"

{
  "sources": {
    "my_source_id": {
      "type": "fluent"
    }
  }
}
...this Vector event is produced:
{
  "host": "34.33.222.212",
  "message": "dummy",
  "tag": "dummy",
  "timestamp": "2021-05-20T20:23:03.021497Z"
}

Dummy message from fluent-bit

Given this event...
dummy.0: [1621541848.161827000, {"message"=>"dummy"}]
...and this configuration...
sources:
  my_source_id:
    type: fluent

[sources.my_source_id]
type = "fluent"

{
  "sources": {
    "my_source_id": {
      "type": "fluent"
    }
  }
}
...this Vector event is produced:
{
  "host": "34.33.222.212",
  "message": "dummy",
  "tag": "dummy.0",
  "timestamp": "2020-05-20T20:17:28.161827Z"
}

How it works

Sending data from fluent agents to Vector aggregators

If you are already running fluent agents (Fluentd or Fluent Bit) in your infrastructure, this source can make it easy to start getting that data into Vector.

Context

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

Fluent Bit configuration

To configure Fluent Bit to forward to a Vector instance, you can use the following output configuration:

	[OUTPUT]
		Name          forward
		Match         *
		# update these to point to your vector instance
		Host          127.0.0.1
		Port          24224

Fluentd configuration

To configure Fluentd to forward to a Vector instance, you can use the following output configuration:

	<match *>
	  @type forward
	  <server>
		# update these to point to your vector instance
		name  local
		host  127.0.0.1
		port 24224
	  </server>
	  compress gzip
	</match>

Secure forward mode support

The fluent source currently supports using TLS, but does not support the authentication part of the Fluent protocol including:

  • Shared key
  • Username and password

And so these options of the secure forward output plugins for Fluent and Fluent Bit cannot be used.

If you would find this useful, please let us know.

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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