@langri-sha/projen-dagger

A projen component for Dagger TypeScript module repositories.

It synthesizes each module's dagger.json, adds the dagger:develop and check:types tasks, ignores the SDK output the Dagger CLI generates, and synthesizes a workflow that regenerates every module against its pinned engine and fails on drift.

@langri-sha/projen-project reaches it through its dagger option, which also keeps Prettier off the SDK-managed files and points Renovate at the engine version. Prefer that over constructing the component yourself.

Usage

npm install -D projen @langri-sha/projen-dagger

import { Project } from 'projen'
import { Dagger } from '@langri-sha/projen-dagger'

const project = new Project({
  name: 'my-modules',
})

const dagger = new Dagger(project, {
  engineVersion: 'v0.21.7',
  modules: {
    tailscale: {},
    paperclip: {
      dependencies: ['../tailscale'],
    },
  },
})

project.synth()

Modules live in top-level directories, each with its own dagger.json.

Modules

Each entry under modules is keyed by the module directory and synthesizes a dagger.json there. The name defaults to the directory, the SDK to typescript. A dependency given as a string is its source ref, named after the last path segment the way dagger install records it:

new Dagger(project, {
  engineVersion: 'v0.21.7',
  modules: {
    'hermes-workspace': {
      dependencies: [
        '../tigerfs',
        '../hermes',
        { name: 'net', source: '../tailscale' },
      ],
    },
  },
})

Call dagger.addModule(directory, options) to add one after construction.

Manifests are written in the field order and formatting the Dagger CLI marshals, without the projen marker, so dagger develop reads them back and leaves them untouched.

Engine versions

engineVersion is declared once, in the projenrc, and written into every manifest from there. Declaring a module without one is an error — the manifests are generated, so there is nowhere else for the pin to live.

Renovate reads it out of the projenrc rather than out of dagger.json, the same way the preset tracks minNodeVersion. An upgrade is then one edit to one file, and the post-upgrade job that runs projen on dependency PRs propagates it to the manifests before the checks run.

Keep it ahead of, or equal to, the engine you develop against locally. The CLI stamps the version it ran into dagger.json, so an older pin and a newer local engine leave synthesis and dagger develop rewriting the field past each other.