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Function Expresssions

The TriggerMesh Integration Language supports a few function expressions which can be used inside configuration blocks to generate attribute values. Those functions are executed at the time a Bridge description is evaluated.

This document provides information about the syntax to use for calling functions inside a Bridge Description File, as well as a reference of all supported functions.

Syntax

A function is represented as an expression composed of an identifier (function name) directly followed by a comma-separated list of arguments between parenthesis, such as:

function(argument1, argument2, ...)

The number and types of arguments as well as the type of the returned value depends on the function.

Functions Reference

file Function

The file function reads a file from the local filesystem and returns its contents as a string.

file(path)

It is particularly relevant for attributes that accept multi-line data, such as in types of target or transformer blocks which embed inline code.

Argument(s)

  • path: path of the file, either absolute or relative to the directory of the Bridge Description file which calls the function.

Example

code = file("functions/my_function.js")

secret_name Function

The sole purpose of the secret_name function is to expand a block's attribute into one or more references to Kubernetes Secrets.

secret_name(name)

It is used in very specific contexts, namely in attributes which represent secrets (e.g. credentials). The result of this function is typically expanded to SecretKeySelectors by implementations that know how to interpret its returned value.

Argument(s)

  • name: name of the Secret object. Must be a valid Kubernetes object name (RFC 1123 subdomain).

Example

api_credentials = secret_name("my-api-credentials")

secret_ref Function

The secret_ref function allows referencing a value from a Kubernetes Secret in attributes which support or require such property.

secret_ref(name, key)

It is used in very specific contexts, such as populating environment variables values in custom applications. The result of this function is an internal representation of a SecretKeySelector.

Argument(s)

  • name: name of the Secret object. Must be a valid Kubernetes object name (RFC 1123 subdomain).
  • key: data key to reference. Must consist of alphanumeric characters, '-', '_' or '.'.

Example

API_TOKEN: secret_ref("my-api-credentials", "token")