Important: This documentation is about an older version. It's relevant only to the release noted, many of the features and functions have been updated or replaced. Please view the current version.

Documentation Grafana Alloy Get started Configuration syntax Expressions Function calls

Function calls

You can use Alloy function calls to build richer expressions.

Functions take zero or more arguments as their input and always return a single value as their output. You can’t construct functions. You can call functions from Alloy’s standard library or export them from a component.

If a function fails, the expression isn’t evaluated, and an error is reported.

Standard library functions

The Alloy configuration syntax contains a standard library of functions. Some functions enable interaction with the host system, for example, reading from an environment variable. Some functions allow for more complex expressions, for example, concatenating arrays or decoding JSON strings into objects.

Alloy Copy

env("HOME")
json_decode(local.file.cfg.content)["namespace"]