Variables
Fluent Bit supports the usage of environment variables in any value associated to a key when using a configuration file.
The variables are case sensitive and can be used in the following format:
When Fluent Bit starts, the configuration reader will detect any request for ${MY_VARIABLE} and will try to resolve its value.
When Fluent Bit is running under systemd (using the official packages), environment variables can be set in the following files:
/etc/default/fluent-bit (Debian based system)
/etc/sysconfig/fluent-bit (Others)
These files are ignored if they do not exist.
Create the following configuration file (fluent-bit.conf):
Open a terminal and set the environment variable:
The above command set the 'stdout' value to the variable MY_OUTPUT.
Run Fluent Bit with the recently created configuration file:
As you can see the service worked properly as the configuration was valid.
