Docker Support

Docker build and publish is handled by each language extension as part of its publish job. There is no standalone Docker extension — each technology plugin knows how to generate a Dockerfile and push images for its own project type.

How it works

When you run putnami publish with Docker options, the language extension:

1. Generates a Dockerfile using its built-in Docker builder (or uses a custom Dockerfile in the project root).
2. Builds the image with docker build.
3. Tags and pushes image(s) to the configured registry.

External tools

• Docker

Per-extension Docker builders

Extension	Base image	Strategy
@putnami/typescript	oven/bun:slim	Copies pre-compiled standalone bundle into container
@putnami/go	gcr.io/distroless/static:nonroot	Copies statically-linked binary
@putnami/python	ghcr.io/astral-sh/uv:python3.12-bookworm-slim	Uses uv for dependency resolution

Each builder implements the DockerImageBuilder interface from @putnami/sdk.

Publish options

Add these flags to putnami publish to enable Docker publishing:

• --docker-registry <registry> — Docker registry URL (or set DOCKER_REGISTRY env var)
• --docker-tag <tag> — Override image tag
• --platform <platform> — Target platform (default: linux/amd64)
• --workspace-builder-image <image> — Workspace builder image for CI multi-stage builds
• --port <number> — Container port to expose (default: 3000)
• --stable — Publish stable version (strips pre-release suffix, tags as latest)

Examples

# Publish with Docker image
putnami publish my-app --docker-registry ghcr.io/myorg

# Stable publish
putnami publish my-app --docker-registry ghcr.io/myorg --stable

# Dry run to preview tags
putnami publish my-app --docker-registry ghcr.io/myorg --dry-run

Project configuration

Enable the docker publish channel in your project's .putnamirc.json:

{
  "publish": ["npm", "docker"]
}

Next steps

• Previous: Python
• Next: CI