Add a package resource

§ 1Purpose

Declare a new resource in a package and implement its check/apply wscript script against the host API.

§ 2Prerequisites

A playbook with a pkgs/<name>/package.wcl already exists.

§ 3Flowchart

§ 4Steps

§ 4.11

§ 4.2Declare the resource and its params

wcl

resource "file_present" {
  description = "Ensure a file exists with the given content"
  script = "resources/file_present.wscript"
  concurrency = "parallel"
  param "path"    { description = "Absolute path"  type = "string"  required = true }
  param "content" { description = "File content"   type = "string"  default = "" }
}

Add a resource block to package.wcl with script (a path relative to the package dir) and a param per input. Params are validated against playbook properties at validation time.

§ 4.32

§ 4.4Implement check() and apply()

rust

use value
use fs
use path

fn check(params: Value) -> Result[CheckResult, string] {
    let p = params.get("path")?.as_string()?
    if !fs::exists(p) { return Ok(CheckResult::NotConfigured) }
    if fs::read(p)? == params.get("content")?.as_string()? {
        Ok(CheckResult::AlreadyConfigured)
    } else { Ok(CheckResult::NotConfigured) }
}

fn apply(params: Value) -> Result[ApplyResult, string] {
    let p = params.get("path")?.as_string()?
    fs::mkdir(path::parent(p))?
    fs::write(p, params.get("content")?.as_string()?)?
    Ok(ApplyResult::Success)
}

The contract

check must never mutate; apply must converge so a re-check returns AlreadyConfigured — even in a fresh process.

Write the script under resources/. Export check(params) and apply(params); import host modules with use. Run config-weave wscripti next to the scripts so the wscript LSP type-checks against the exact host surface.

§ 4.53

§ 4.6Validate the script compiles

console

$ config-weave validate ./my-playbook
ok

Run config-weave validate — its final stage compiles every wscript script against the host API, so a bad signature or unknown host function is a hard error.

Verification

config-weave validate exits 0 with the new resource's script compiled.