Introduction
In this tutorial you will learn how to create and work with CUE modules, using the Central Registry.
Along the way you will:
- Create a module that depends on an existing, well-known module
- Use
cue mod tidy
to automatically add dependencies and their versions to themodule.cue
file
Create a module
Initialize a local CUE module. We will not publish this module:
$ cue mod init glacial-tech.example/frostyapp@v0
We refer to such a module as the main module. Because we won’t publish this module, its module path is not significant. The module path we have chosen makes this guide consistent with its companion tutorial Working with a custom module registry.
Create the code for the new module:
package frostyapp
import "github.com/cue-labs/examples/frostyconfig@v0"
config: frostyconfig.#Config & {
appName: "alpha"
port: 80
features: logging: true
}
This imports the frostyconfig
package first introduced in the tutorial
Working with a custom module registry.
Instead of depending on a version of that module published to a custom
registry, we have instead published a version to the Central Registry.
In our local module we define some concrete values for the configuration,
constrained by the frostyconfig.#Config
schema.
Ensure the module is tidy, pulling all dependencies:
$ cue mod tidy
If you see an error message mentioning “too many requests” then login to the Central Registry and re-run this command. The Central Registry allows more requests from authenticated users.
We can see that the dependencies have now been added to the cue.mod/module.cue
file:
$ cat cue.mod/module.cue
module: "glacial-tech.example/frostyapp@v0"
language: {
version: "v0.13.0"
}
deps: {
"github.com/cue-labs/examples/frostyconfig@v0": {
v: "v0.0.1"
}
}
Evaluate the configuration
Export the configuration as YAML:
$ cue export --out yaml
config:
appName: alpha
port: 80
features:
logging: true
Congratulations!
That’s it, you have just created a local module that depends on a well-known module from the Central Registry!
Related content
- Tutorial: Publishing modules to the Central Registry
- Tutorial: Working with a custom module registry
- Reference: CUE Modules