Fluent Bit provides integrated support for Transport Layer Security (TLS) and it predecessor Secure Sockets Layer (SSL) respectively. In this section we will refer as TLS only for both implementations.

Each output plugin that requires to perform Network I/O can optionally enable TLS and configure the behavior. The following table describes the properties available:

The listed properties can be enabled in the configuration file, specifically on each output plugin section or directly through the command line.

The following output plugins can take advantage of the TLS feature:

• ​Azure​

• ​BigQuery​

• ​Datadog​

• ​Elasticsearch​

• ​Forward​

• ​GELF​

• ​HTTP​

• ​InfluxDB​

• ​Kafka REST Proxy​

• Slack

• ​Splunk​

• ​Stackdriver​

• ​TCP & TLS​

• ​Treasure Data​

In addition, other plugins implements a sub-set of TLS support, meaning, with restricted configuration:

• ​Kubernetes Filter​

Example: enable TLS on HTTP output

By default HTTP output plugin uses plain TCP, enabling TLS from the command line can be done with:

$ fluent-bit -i cpu -t cpu -o http://192.168.2.3:80/something \
    -p tls=on         \
    -p tls.verify=off \
    -m '*'

In the command line above, the two properties tls and tls.verify where enabled for demonstration purposes (we strongly suggest always keep verification ON).

The same behavior can be accomplished using a configuration file:

[INPUT]
    Name  cpu
    Tag   cpu
​
[OUTPUT]
    Name       http
    Match      *
    Host       192.168.2.3
    Port       80
    URI        /something
    tls        On
    tls.verify Off

Tips and Tricks

Connect to virtual servers using TLS

Fluent Bit supports TLS server name indication. If you are serving multiple hostnames on a single IP address (a.k.a. virtual hosting), you can make use of tls.vhost to connect to a specific hostname.

[INPUT]
    Name  cpu
    Tag   cpu
​
[OUTPUT]
    Name        forward
    Match       *
    Host        192.168.10.100
    Port        24224
    tls         On
    tls.verify  On
    tls.ca_file /etc/certs/fluent.crt
    tls.vhost   fluent.example.com