BuildKit vs Skaffold

BuildKit is a free toolkit for turning source code into build artifacts. It consists of the buildkitd daemon and buildctl client, and uses LLB, a binary format for describing process dependency graphs. Builds can use Dockerfiles or other LLB-compatible frontends, resolve dependencies concurrently, cache instructions, import and export caches, run nested jobs, and collect unused data automatically. BuildKit supports execution without root privileges and OCI (runc) or containerd workers. Results can be exported as images, local directories, tarballs, Docker tarballs, or OCI tarballs. Cache options include inline, registry, local-directory, and GitHub Actions backends; the README marks GitHub Actions, S3, and Azure Blob options experimental. The daemon provides a gRPC API over a Unix socket by default, with TCP sockets also supported. Binaries are available for Linux, macOS, and Windows. The unofficial Homebrew formula for macOS omits buildkitd; the project gives Lima in a Linux virtual machine as one way to run it. BuildKit is licensed under Apache-2.0.

Skaffold is Google’s open-source project for building, pushing and deploying applications. It runs client-side and has no component installed on a cluster. In development mode, it watches source files and can rebuild images, synchronize files, test images and redeploy when changes are detected. Its command-line interface can build, test, render, apply, deploy and clean application artifacts. Listed capabilities include policy-based image tagging, resource port-forwarding, logging and file syncing. Builder integrations include Docker, Jib, Bazel, custom builders, Buildpacks and ko. Deployment options include kubectl, kpt, Helm, Docker, Google Cloud Run, Kustomize and Render. Cloud Code provides extensions for Visual Studio Code and JetBrains IDEs. Skaffold supports Linux, macOS and Windows and is listed at free as an open-source project with standalone CLI and IDE integrations. It checks Google servers for updates by default, although that check can be disabled. Installation documentation says anonymized usage data is collected with an opt-out. Its gRPC server is not compatible with HTTPS.