Custom Types

A Dagger Module can have multiple object types defined. It's important to understand that they are only accessible through chaining, starting from a function in the main object.

Here is an example of a function named DaggerOrganization that returns a custom Organization type, itself containing a collection of Account types:

package main

type Github struct{}

func (module *Github) DaggerOrganization() *Organization {
	return &Organization{
		URL:          "https://github.com/dagger",
		Repositories: []*GitRepository{dag.Git(`${organization.url}/dagger`)},
		Members: []*Account{
			{"jane", "jane@example.com"},
			{"john", "john@example.com"},
		},
	}
}

type Account struct {
	Username string
	Email    string
}

func (account *Account) URL() string {
	return "https://github.com/" + account.Username
}

type Organization struct {
	URL          string
	Repositories []*GitRepository
	Members      []*Account
}

note

When the Dagger Engine extends the Dagger API schema with these types, it prefixes their names with the name of the main object:

• Github
• GithubAccount
• GithubOrganization

This is to prevent possible naming conflicts when loading multiple modules, which is reflected in code generation (for example, when using this module in another one as a dependency).

Here's an example of calling this module to get all member URLs:

dagger call dagger-organization members url

The result will be:

https://github.com/jane
https://github.com/john