| name | containerfile |
| version | 1.1 |
| last_updated | 2026-08-08 |
| id | containerfile |
| one_line_purpose | Modify and locally test the common Containerfile build. |
| entry_point | docs/skills/containerfile/SKILL.md |
| category | ci-ops |
| mcp_compliance_level | partial |
| optimization_status | draft |
| status | active |
| dependencies | [] |
| tags | ["containerfile","build","oci"] |
| description | Containerfile build structure and local testing. Use when modifying the Containerfile, adding binaries, updating wallpaper sources, or using just overlay. |
| metadata | {"type":"reference"} |
Containerfile — common OCI layer build
When to Use
Use when modifying the Containerfile, adding new external binaries, updating
wallpaper sources, changing the umotd/uwelcome version pins, or running
just overlay to test system_files/ changes locally.
When Not to Use
Do not use this skill for changes that only affect system_files/ content
without touching the Containerfile build stages, or for downstream image
Containerfiles outside projectbluefin/common.
Build Stages Overview
The Containerfile uses four named stages:
| Stage | Purpose |
|---|
umotd-build | Go builder for the MOTD tips binary |
uwelcome-build | Go builder for the CLI welcome banner binary |
build | Downloads and assembles all artifacts into /out/ |
ctx | Scratch image: the OCI layer consumed by downstream builds |
See references/build-stages.md for the full stage details, wallpaper source caveat, and ujust completion generation.
Key Rules
- Never download a pre-built binary for
umotd/uwelcome — use the Go builder stage pattern.
- Never add a
curl download without a paired sha256sum -c check.
- Git checkout pins must be commit SHAs, not tags or branch names.
- Place shared binaries in
/out/shared/, Bluefin-specific in /out/bluefin/.
Red Flags
checkout tags/... or --branch in a Go builder stage — tags are mutable.- A
curl block without an inline sha256sum -c.
- Editing generated ujust completions directly instead of fixing the
sed pattern.
- Using
ghcr.io/projectbluefin/ for the wallpaper source (it is ).
