Packer
Built-in functions overview
This topic provides an overview of the built-in HashiCorp configuration language (HCL) functions you can use in your Packer templates.
Functions syntax
You can use functions in Packer templates to transform and combine values. The syntax for function calls is a function name followed by comma-separated arguments in parentheses:
max(5, 12, 9)
For information on invoking functions in string literals, refer to the string literals reference section.
HCL does not support user-defined functions. You can only call the functions built into the language.