images

Images

Each subdirectory contains a Dockerfile for a supported language. clstr embeds these at build time via embed.go and serves them to users running clstr init.

Requirements

Every Dockerfile must install iptables and iproute2. clstr uses these to simulate network conditions (latency, partitions, packet loss) between nodes. Without them, network fault injection will not work.

Adding a language

1. Create a new directory under images/ named after the language (e.g. images/python).
2. Copy images/template/Dockerfile as a starting point and fill in the language-specific steps.
3. If you want to support common aliases (e.g. py -> python), add them to the aliases map in embed.go.
4. Add a Dependabot entry for the new directory in .github/dependabot.yaml, sorted alphabetically within the existing docker entries.

Updating a language version

Change the FROM line in the relevant Dockerfile. Dependabot will open PRs for minor and major version bumps automatically; patch updates are ignored.

When adding a Dependabot entry, note that languages differ in how they version their Docker images. Some use minor versions as the meaningful unit (e.g. python:3.13, go:1.26, rust:1.85, elixir:1.18), so patch updates should be ignored. Others use major versions (e.g. node:22, node:24), so minor updates should be ignored instead. Follow the pattern in the existing entries and adjust the ignore block accordingly.