multi-stage-build¶

Multi-stage build with rollback points.

Description¶

The multi-stage-build prompt provides instructions for complex builds with multiple stages, each creating a checkpoint for potential rollback.

Parameters¶

Parameter	Type	Required	Default	Description
`source`	string	Yes	-	Local directory path to sync
`install_cmd`	string	No	`pip install -e .`	Dependency installation command
`build_cmd`	string	No	`python -m build`	Build command
`test_cmd`	string	No	`pytest`	Test command

Generated Instructions¶

When invoked with:

{
  "source": "/home/user/project",
  "install_cmd": "pip install -e '.[dev]'",
  "build_cmd": "python -m build",
  "test_cmd": "pytest -v"
}

Returns:

Execute a multi-stage build with rollback checkpoints:

Source: `/home/user/project`

**Stage 1: Setup Base**
1. Check if `tag:python:3.11-slim` exists, import if needed
2. Sync source files with `rsync`

**Stage 2: Install Dependencies** (checkpoint: `deps-installed`)
1. Run `pip install -e '.[dev]'` with `disposable=false`
2. Save `result_image` as rollback point
3. If this fails, report error and stop

**Stage 3: Build** (checkpoint: `build-complete`)
1. Run `python -m build` on deps image with `disposable=false`
2. Save `result_image` as rollback point
3. If this fails, can rollback to deps-installed image

**Stage 4: Test**
1. Run `pytest -v` on build image (disposable=true for tests)
2. Report test results
3. If tests fail, can rollback to build-complete or deps-installed

**Rollback Strategy:**
- Keep track of each stage's `result_image` UUID
- On failure, report which checkpoint to resume from
- Previous checkpoints remain valid for retry

Example Usage¶

Python Package Build¶

{
  "prompt": "multi-stage-build",
  "args": {
    "source": "/path/to/package"
  }
}

Custom Build Pipeline¶

{
  "prompt": "multi-stage-build",
  "args": {
    "source": "/path/to/project",
    "install_cmd": "pip install poetry && poetry install",
    "build_cmd": "poetry build",
    "test_cmd": "poetry run pytest --cov"
  }
}

Rust Project¶

{
  "prompt": "multi-stage-build",
  "args": {
    "source": "/path/to/rust-project",
    "install_cmd": "cargo fetch",
    "build_cmd": "cargo build --release",
    "test_cmd": "cargo test"
  }
}

Stage Details¶

Stage 1: Setup Base¶

Ensures base image exists
Syncs source files
No checkpoint needed (base image is the checkpoint)

Stage 2: Install Dependencies¶

Runs install command with disposable=false
Saves result as deps-installed checkpoint
Rollback target: If install fails, fix and retry from base

Stage 3: Build¶

Runs build command with disposable=false
Saves result as build-complete checkpoint
Rollback target: If build fails, can retry from deps-installed

Stage 4: Test¶

Runs tests with disposable=true (no need to save test artifacts)
Reports results
Rollback targets: Can retry from build-complete or deps-installed

Implementation Notes¶

The agent should track checkpoints:

base_image = "tag:python:3.11-slim"
      |
      v
deps_image = run(install_cmd, disposable=false).result_image
      |
      v
build_image = run(build_cmd, image=deps_image, disposable=false).result_image
      |
      v
test_result = run(test_cmd, image=build_image, disposable=true)

On failure at any stage, report:

Which stage failed
Available rollback points
How to resume