TCP and TLS

The tcp output plugin allows to send records to a remote TCP server. The payload can be formatted in different ways as required.

Configuration Parameters

Key	Description	default
Host	Target host where Fluent-Bit or Fluentd are listening for Forward messages.	127.0.0.1
Port	TCP Port of the target service.	5170
Format	Specify the data format to be printed. Supported formats are msgpack json, json_lines and json_stream.	msgpack
json_date_key	Specify the name of the time key in the output record. To disable the time key just set the value to false.	date
json_date_format	Specify the format of the date. Supported formats are double, epoch, iso8601 (eg: 2018-05-30T09:39:52.000681Z) and java_sql_timestamp (eg: 2018-05-30 09:39:52.000681)	double
workers	The number of workers to perform flush operations for this output.	2

TLS Configuration Parameters

The following parameters are available to configure a secure channel connection through TLS:

Key	Description	Default
tls	Enable or disable TLS support	Off
tls.verify	Force certificate validation	On
tls.debug	Set TLS debug verbosity level. It accept the following values: 0 (No debug), 1 (Error), 2 (State change), 3 (Informational) and 4 Verbose	1
tls.ca_file	Absolute path to CA certificate file
tls.crt_file	Absolute path to Certificate file.
tls.key_file	Absolute path to private Key file.
tls.key_passwd	Optional password for tls.key_file file.

Command Line

JSON format

bin/fluent-bit -i cpu -o tcp://127.0.0.1:5170 -p format=json_lines -v

We have specified to gather CPU usage metrics and send them in JSON lines mode to a remote end-point using netcat service.

Run the following in a separate terminal, netcat will start listening for messages on TCP port 5170. Once it connects to Fluent Bit ou should see the output as above in JSON format:

$ nc -l 5170
{"date":1644834856.905985,"cpu_p":1.1875,"user_p":0.5625,"system_p":0.625,"cpu0.p_cpu":0.0,"cpu0.p_user":0.0,"cpu0.p_system":0.0,"cpu1.p_cpu":1.0,"cpu1.p_user":1.0,"cpu1.p_system":0.0,"cpu2.p_cpu":4.0,"cpu2.p_user":2.0,"cpu2.p_system":2.0,"cpu3.p_cpu":1.0,"cpu3.p_user":0.0,"cpu3.p_system":1.0,"cpu4.p_cpu":1.0,"cpu4.p_user":0.0,"cpu4.p_system":1.0,"cpu5.p_cpu":1.0,"cpu5.p_user":1.0,"cpu5.p_system":0.0,"cpu6.p_cpu":0.0,"cpu6.p_user":0.0,"cpu6.p_system":0.0,"cpu7.p_cpu":3.0,"cpu7.p_user":1.0,"cpu7.p_system":2.0,"cpu8.p_cpu":0.0,"cpu8.p_user":0.0,"cpu8.p_system":0.0,"cpu9.p_cpu":1.0,"cpu9.p_user":0.0,"cpu9.p_system":1.0,"cpu10.p_cpu":1.0,"cpu10.p_user":0.0,"cpu10.p_system":1.0,"cpu11.p_cpu":0.0,"cpu11.p_user":0.0,"cpu11.p_system":0.0,"cpu12.p_cpu":0.0,"cpu12.p_user":0.0,"cpu12.p_system":0.0,"cpu13.p_cpu":3.0,"cpu13.p_user":2.0,"cpu13.p_system":1.0,"cpu14.p_cpu":1.0,"cpu14.p_user":1.0,"cpu14.p_system":0.0,"cpu15.p_cpu":0.0,"cpu15.p_user":0.0,"cpu15.p_system":0.0}

Msgpack format

Repeat the JSON approach but using the msgpack output format.

bin/fluent-bit -i cpu -o tcp://127.0.0.1:5170 -p format=msgpack -v

We could send this to stdout but as it is a serialized format you would end up with strange output. This should really be handled by a msgpack receiver to unpack as per the details in the developer documentation here. As an example we use the Python msgpack library to deal with it:

#Python3
import socket
import msgpack

unpacker = msgpack.Unpacker(use_list=False, raw=False)
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
s.bind(("127.0.0.1", 5170))
s.listen(1)
connection, address = s.accept()

while True:
    data = connection.recv(1024)
    if not data:
        break
    unpacker.feed(data)
    for unpacked in unpacker:
        print(unpacked)

$ pip install msgpack
$ python3 test.py
(ExtType(code=0, data=b'b\n5\xc65\x05\x14\xac'), {'cpu_p': 0.1875, 'user_p': 0.125, 'system_p': 0.0625, 'cpu0.p_cpu': 0.0, 'cpu0.p_user': 0.0, 'cpu0.p_system': 0.0, 'cpu1.p_cpu': 0.0, 'cpu1.p_user': 0.0, 'cpu1.p_system': 0.0, 'cpu2.p_cpu': 1.0, 'cpu2.p_user': 0.0, 'cpu2.p_system': 1.0, 'cpu3.p_cpu': 0.0, 'cpu3.p_user': 0.0, 'cpu3.p_system': 0.0, 'cpu4.p_cpu': 0.0, 'cpu4.p_user': 0.0, 'cpu4.p_system': 0.0, 'cpu5.p_cpu': 0.0, 'cpu5.p_user': 0.0, 'cpu5.p_system': 0.0, 'cpu6.p_cpu': 0.0, 'cpu6.p_user': 0.0, 'cpu6.p_system': 0.0, 'cpu7.p_cpu': 0.0, 'cpu7.p_user': 0.0, 'cpu7.p_system': 0.0, 'cpu8.p_cpu': 0.0, 'cpu8.p_user': 0.0, 'cpu8.p_system': 0.0, 'cpu9.p_cpu': 1.0, 'cpu9.p_user': 1.0, 'cpu9.p_system': 0.0, 'cpu10.p_cpu': 0.0, 'cpu10.p_user': 0.0, 'cpu10.p_system': 0.0, 'cpu11.p_cpu': 0.0, 'cpu11.p_user': 0.0, 'cpu11.p_system': 0.0, 'cpu12.p_cpu': 0.0, 'cpu12.p_user': 0.0, 'cpu12.p_system': 0.0, 'cpu13.p_cpu': 0.0, 'cpu13.p_user': 0.0, 'cpu13.p_system': 0.0, 'cpu14.p_cpu': 0.0, 'cpu14.p_user': 0.0, 'cpu14.p_system': 0.0, 'cpu15.p_cpu': 0.0, 'cpu15.p_user': 0.0, 'cpu15.p_system': 0.0})