# TCP & 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            | Enables dedicated thread(s) for this output. Default value is set since version 1.8.13. For previous versions is 0.                                                                  | 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

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

We have specified to gather [CPU](https://github.com/fluent/fluent-bit-docs/tree/16f30161dc4c79d407cd9c586a0c6839d0969d97/pipeline/input/cpu.md) 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:

```bash
$ 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.

```bash
$ 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](https://github.com/fluent/fluent-bit-docs/blob/master/development/msgpack-format.md). As an example we use the [Python msgpack library](https://msgpack.org/#languages) to deal with it:

```python
#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)
```

```bash
$ 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})

```