Functions

Available functions.

In addition to the provided builtin global functions, kluctl also provides a few global functions:

load_template(file)

Loads the given file into memory, renders it with the current Jinja2 context and then returns it as a string. Example:

{% set a=load_template('file.yaml') %}
{{ a }}

load_template uses the same path searching rules as described in includes/imports.

load_sha256(file, digest_len)

Loads the given file into memory, renders it and calculates the sha256 hash of the result.

The filename given to load_sha256 is treated the same as in load_template. Recursive loading/calculating of hashes is allowed and is solved by replacing load_sha256 invocations with currently loaded templates with dummy strings. This also allows to calculate the hash of the currently rendered template, for example:

apiVersion: v1
kind: ConfigMap
metadata:
  name: my-config-{{ load_sha256("configmap.yaml") }}
data:

digest_len is an optional parameter that allows to limit the length of the returned hex digest.

get_var(field_path, default)

Convenience method to navigate through the current context variables via a JSON Path. Let’s assume you currently have these variables defined (e.g. via vars):

my:
  deep:
    var: value

Then {{ get_var('my.deep.var', 'my-default') }} would return value. When any of the elements inside the field path are non-existent, the given default value is returned instead.

The field_path parameter can also be a list of pathes, which are then tried one after the another, returning the first result that gives a value that is not None. For example, {{ get_var(['non.existing.var', my.deep.var'], 'my-default') }} would also return value.

merge_dict(d1, d2)

Clones d1 and then recursively merges d2 into it and returns the result. Values inside d2 will override values in d1.

update_dict(d1, d2)

Same as merge_dict, but merging is performed in-place into d1.

raise(msg)

Raises a python exception with the given message. This causes the current command to abort.

debug_print(msg)

Prints a line to stderr.