Rockcraft – Canonical’s CLI tool for container images | Ubuntu

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A rock solid foundation for crafting containers
Build minimal, hardened, OCI-compliant Ubuntu container images with Rockcraft.
Let Rockcraft handle the boilerplate of your container builds so you can focus on your application’s code.
Rockcraft is Canonical’s specialized CLI tool for creating rocks, a new generation of securely-designed, stable, and OCI-compliant container images, based on Ubuntu.
Rockcraft supports a variety of language-specific plugins, removing the overhead for a developer to set up their own language environment in order to build and stage their application into the final container image.
Rockcraft integrates with Canonical’s Chisel tool to build minimal container images from slices of the Ubuntu distribution, ensuring that customers package only what is needed for their application, and nothing more.
Rockcraft uses a declarative, rather than imperative, approach to build containers. This lowers the barrier to entry for new container developers, while saving time and reducing maintenance overhead for experienced engineers.
Rockcraft is built on top of existing concepts within the same family as Snapcraft and Charmcraft, making adoption seamless for developers that are already building snaps and charms.
Learn about some of the high-level commands you can use to build a rock, from generating the base configuration file to publishing a rock to a registry.
Run rockcraft init to generate a base rockcraft.yaml
Rockcraft offers various extensions, including spring-boot-framework. Using the above command, Rockcraft automates the creation of a rockcraft.yaml file and tailors the file for a Spring Boot application.
Define your application dependencies, base OS, and parts in the rockcraft.yaml file.
Run rockcraft pack to process parts and create the final artefact.
Publish a rock to a registry.
Rockcraft forgoes the traditional, linear execution of Dockerfiles in favor of a declarative, component-based architecture.
Rockcraft divides your app into modular blocks called parts. When a part is processed, it performs steps from the parts lifecycle: pull, overlay, build, stage, and prime.
Learn more about parts ›
Declarative chiseling
Rockcraft natively integrates with Chisel directly inside the YAML. Rather than starting with a full OS layer, developers can select the bare base and define precise slices.
Learn about rockcraft.yaml ›
You do not need to write custom build scripts or manually configure virtual environments. Rockcraft handles ecosystem-specific build logic natively through its plugin ecosystem.
Explore Rockcraft plugins ›
Rockcraft provides built-in extensions for modern cloud-native web apps (Django, Flask, FastAPI, Node.js, Go), which silently inject a pre-configured underlying part.
Set up a 12-factor app rock ›
Get started with Rockcraft.
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