Functions

You can use basic Go template language and Sprig functions to modify the text of a stack template.

Additionally, you can use some enhanced functions that are listed below. These functions are integrated with the yaml syntax and can't be used everywhere.

insertYAML

Allows for passing yaml block as a value of target yaml template.

Argument: data to pass, any value or reference to a block.

Allowed use: only as full yaml value, in unit inputs. Example:

Source yaml:

  values:
    node_groups:
      - name: ng1
        min_size: 1
        max_size: 5
      - name: ng2
        max_size: 2
        type: spot

Target yaml template:

  units:
    - name: k3s
      type: tfmodule
      node_groups: {{ insertYAML .values.node_groups }}

Rendered stack template:

  units:
    - name: k3s
      type: tfmodule
      node_groups:
        - name: ng1
          min_size: 1
          max_size: 5
        - name: ng2
          max_size: 2
          type: spot

remoteState

Allows for passing data across units and stacks, can be used in pre/post hooks.

Argument: string, path to remote state consisting of 3 parts separated by a dot: "stack_name.unit_name.output_name". Since the name of the stack is unknown inside the stack template, you can use "this" instead:"this.unit_name.output_name".

Allowed use:

• all units types: in inputs;

• all units types: in units pre/post hooks;

• in Kubernetes modules: in Kubernetes manifests.

cidrSubnet

Calculates a subnet address within given IP network address prefix. Same as Terraform function. Example:

Source:

  {{ cidrSubnet "172.16.0.0/12" 4 2 }}

Rendered:

  172.18.0.0/16