Templating

Templates allow you to interpolate values from Flags, Arguments and Configuration into some aspects of commands.

For example the exec command type allows you to use templates to put arguments into the command being run.

We use the Go template language at the moment, it’s not the best we might look at something else later.

Only some fields are parsed through templates, the documentation for each command type will call out what is supported.

Reference

An example template use was shown in the exec documentation:

command: |
            {{ default .Config.Cowsay "cowsay" }} "{{ .Arguments.message | escape }}"

Here we have examples of accessing the .Config and .Arguments structures and using some functions.

Key	Description
`.Config`	Data stored in the configuration file for this application
`.Arguments`	Data supplied by users using command arguments
`.Flags`	Data supplied by users using command flags
`.Input`	Parsed JSON input from a previous step, available in transform contexts only

Function	Description	Example
`require`	Asserts that some data is available, errors with an optional custom message on failure	`{{ require .Config.Password "Password not set in the configuration" }}`
`escape`	Escapes a string for use in shell arguments	`{{ escape .Arguments.message }}`
`read_file`	Reads a file	`{{ read_file .Arguments.file }}`
`default`	Checks a value, if its not supplied uses a default	`{{ default .Config.Cowsay "cowsay" }}`
`env`	Reads an environment variable	`{{ env "HOME" }}`
`UserWorkingDir`	Returns the directory the user is in when running the command	`{{ UserWorkingDir }}`
`AppDir`	Returns the directory the application definition is in	`{{ AppDir }}`
`TaskDir`	Alias for `AppDir`	`{{ TaskDir }}`

In addition to the above, the Sprig functions library is available in most template contexts including commands, scaffolds and transforms.