Charmcraft wrapper

.github/workflows/integration_test.yaml

@@ -15,14 +15,6 @@ on:
         description: Label for building the charm
         type: string
         default: ubuntu-latest
-      charmcraftcache:
-        description: Use charmcraftcache (https://github.com/canonical/charmcraftcache)
-        type: boolean
-        default: false
-      charmcraft-channel:
-        description: Charmcraft channel to use for the integration test
-        type: string
-        default: latest/stable
       channel:
         description: Actions operator provider channel as per https://github.com/charmed-kubernetes/actions-operator#usage
         type: string
@@ -264,20 +256,17 @@ jobs:
         if: ${{ inputs.rockcraft-enable-security-nesting }}
         run: |
           lxc profile set default security.nesting true
-      - name: Install charmcraftcache
-        if: ${{ inputs.charmcraftcache }}
+      - name: Install builder
         run: |
-          pipx install charmcraftcache
+          pipx install git+https://github.com/canonical/superbuild@0.1.0
       - uses: actions/checkout@v6.0.2
       - name: Pre-build script
         if: ${{ inputs.pre-build-script != '' }}
         run: bash -xe ${{ inputs.pre-build-script }}
-      - uses: canonical/operator-workflows/internal/build@main
+      - uses: canonical/operator-workflows/internal/build@charmcraft-wrapper
         id: build
         with:
           build-plan: ${{ toJSON(matrix.build) }}
-          charmcraftcache: ${{ inputs.charmcraftcache }}
-          charmcraft-channel: ${{ inputs.charmcraft-channel }}
           github-token: ${{ secrets.GITHUB_TOKEN }}
           rockcraft-channel: ${{ inputs.rockcraft-channel }}
 

docs/changelog.md

@@ -6,8 +6,13 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 
 Each revision is versioned by the date of the revision.
 
+## 2026-03-11
+
+- Build charms using the charmcraft wrapper.
+
 ## 2026-03-10
 
+- Drop support for charmcraftcache
 - Drop leftover registry input.
 
 ## 2026-03-09

internal/build/action.yaml

@@ -5,12 +5,6 @@ inputs:
   build-plan:
     description: Build plan.
     required: true
-  charmcraftcache:
-    description: Use charmcraftcache (https://github.com/canonical/charmcraftcache)
-    default: "false"
-  charmcraft-channel:
-    description: Charmcraft channel to use for the integration test
-    default: latest/stable
   github-token:
     description: github token.
     required: true

src/build.ts

@@ -14,7 +14,6 @@ import path from 'path'
 
 interface BuildCharmParams {
   plan: BuildPlan
-  charmcraftChannel: string
 }
 
 async function gitTreeId(p: string): Promise<string> {
@@ -29,32 +28,25 @@ async function gitTreeId(p: string): Promise<string> {
 }
 
 async function buildCharm(params: BuildCharmParams): Promise<void> {
-  if (params.charmcraftChannel) {
-    await exec.exec('sudo', [
-      'snap',
-      'install',
-      'charmcraft',
-      '--channel',
-      params.charmcraftChannel,
-      '--classic'
-    ])
-  } else {
-    await exec.exec('sudo', ['snap', 'install', 'charmcraft', '--classic'])
-  }
-  core.startGroup('charmcraft pack')
-  const charmcraftBin = core.getBooleanInput('charmcraftcache')
-    ? 'ccc'
-    : 'charmcraft'
-  await exec.exec(charmcraftBin, ['pack', '--verbosity', 'trace'], {
-    cwd: params.plan.source_directory,
-    env: { ...process.env, CHARMCRAFT_ENABLE_EXPERIMENTAL_EXTENSIONS: 'true' }
-  })
+  core.startGroup('superbuild pack')
+  await exec.exec(
+    'superbuild',
+    [
+      'pack',
+      '--verbose',
+      '--build-context',
+      '.',
+      '--project-dir',
+      params.plan.source_directory
+    ],
+    {
+      env: { ...process.env, CHARMCRAFT_ENABLE_EXPERIMENTAL_EXTENSIONS: 'true' }
+    }
+  )
   core.endGroup()
-  const charmFiles = await (
-    await glob.create(path.join(params.plan.source_directory, '*.charm'))
-  ).glob()
+  const charmFiles = await (await glob.create(path.join('.', '*.charm'))).glob()
   const artifact = new DefaultArtifactClient()
-  const manifestFile = path.join(params.plan.source_directory, 'manifest.json')
+  const manifestFile = path.join('.', 'manifest.json')
   fs.writeFileSync(
     manifestFile,
     JSON.stringify(
@@ -66,7 +58,7 @@ async function buildCharm(params: BuildCharmParams): Promise<void> {
   await artifact.uploadArtifact(
     params.plan.output,
     [...charmFiles, manifestFile],
-    params.plan.source_directory
+    '.'
   )
 }
 
@@ -356,8 +348,7 @@ export async function run(): Promise<void> {
     switch (plan.type) {
       case 'charm':
         await buildCharm({
-          plan,
-          charmcraftChannel: core.getInput('charmcraft-channel')
+          plan
         })
         break
       case 'docker-image':

superbuild/.gitignore

@@ -0,0 +1,3 @@
+build
+*.egg-info
+**/__pycache__/

superbuild/README.md

@@ -0,0 +1,70 @@
+# superbuild
+
+`superbuild` is a thin Python wrapper around [charmcraft](https://juju.is/docs/sdk/charmcraft).
+It ensures `charmcraft` is installed on the machine and transparently forwards all arguments to it,
+with one extra convenience: a `--build-context` option that lets you supply an external directory
+of source files to include in the build without modifying your project tree.
+
+## Features
+
+- Auto-installs the latest `charmcraft` via `snap` if it is not already present.
+- Accepts an optional `--build-context <dir>` argument (see below).
+- All other arguments and flags are passed through to `charmcraft` unchanged.
+- After the build, any `.charm` files whose name matches the `name` key in `charmcraft.yaml`
+  are copied back to the current working directory automatically.
+
+## Requirements
+
+- Python 3.8+
+- `snap` (for automatic `charmcraft` installation)
+- `pyyaml` (installed automatically as a dependency)
+
+## Installation
+
+```bash
+pip install ./superbuild
+```
+
+Or, for development:
+
+```bash
+pip install -e ./superbuild
+```
+
+## Usage
+
+```
+superbuild [--build-context <dir>] <charmcraft command and args>
+```
+
+### Without `--build-context`
+
+`superbuild` behaves exactly like calling `charmcraft` directly:
+
+```bash
+superbuild pack
+superbuild version
+superbuild upload my-charm_ubuntu-22.04-amd64.charm
+```
+
+### With `--build-context`
+
+Provide a directory whose contents will be merged with the `charmcraft.yaml` from the current
+working directory into a temporary build directory. This is useful when your source files live
+separately from your charm metadata.
+
+```bash
+superbuild --build-context ./src pack
+```
+
+What happens internally:
+
+1. A temporary directory is created.
+2. `charmcraft.yaml` from the **current working directory** (if present) is copied in.
+3. All files and subdirectories from `--build-context` are copied in alongside it.
+4. `charmcraft` is executed with the remaining arguments inside that temporary directory.
+5. Any resulting `.charm` files whose filename starts with the charm `name` are copied back
+   to the current working directory.
+6. The temporary directory is cleaned up.
+
+If `--build-context` is omitted, the current working directory is used as the context.

superbuild/pyproject.toml

@@ -0,0 +1,19 @@
+# Copyright 2026 Canonical Ltd.
+# See LICENSE file for licensing details.
+
+[build-system]
+requires = ["setuptools>=61"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "superbuild"
+version = "0.1.0"
+description = "Thin wrapper that ensures charmcraft is installed and forwards all arguments to it"
+requires-python = ">=3.8"
+dependencies = ["pyyaml"]
+
+[tool.pytest.ini_options]
+testpaths = ["tests"]
+
+[project.scripts]
+superbuild = "superbuild.main:main"

superbuild/superbuild/__init__.py

@@ -0,0 +1,5 @@
+#!/usr/bin/env python3
+
+# Copyright 2025 Canonical Ltd.
+# See LICENSE file for licensing details.
+