Functions

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

Additionally, you can use some enhanced functions that are listed below.

insertYAML

Pass yaml block as a value of target yaml template.

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

The insertYAML function is integrated with the yaml syntax and can be used only as a full yaml value in units input. 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

Pass data across units and stacks, can be used in pre/post hooks.

Important

The function can take input only from Terraform-based units, i.e. Tfmodule, Kubernetes, Helm, and Printer.

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".

The remoteState function is integrated with the yaml syntax and can be used in following cases:

• In units' inputs (all types of units)

• In units' pre/post hooks (all types of units)

• In Kubernetes manifests (Kubernetes units)

cidrSubnet

Calculate 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

readFile

Read the passed file and return its contents as a string.

Argument: path. The readFile function supports both absolute readFile /path/to/file.txt and relative paths readFile ./files/data.yaml.

A relative path must refer to a location where the function is used. When it is used in a template, the path's base folder will be the template directory. When it is used in one of the project files, the path will begin with the project directory.

Note

The file is read as is; templating is not applied.

workDir

Return the absolute path to a working directory where a project runs, and the Terraform code is generated.

Warning

Use the function with caution since the absolute path that it returns varies depending on running conditions. This can affect the Cluster.dev's state.

templatePath

Return the absolute path to the stackTemplate directory. It is designed exclusively for use within templates and cannot be employed in other objects, such as a project or stack.

reqEnv

Return an environment variable required for a system to run.

Argument: ENVNAME.

Specifying a non-existent variable in reqEnv function will result in failing cdev apply with an error message.

bcrypt

Apply the bcrypt encryption algorithm to a passed string.

Warning

Use the function with caution since it returns a unique hash with each calling, which can affect the Cluster.dev’s state.