overthinkos/ubuntu-builder

ubuntu-builder

Ubuntu 24.04 (noble) counterpart of /charly-distros:fedora-builder and /charly-distros:debian-builder. Same role — pixi/npm/cargo multi-stage builder — with one important difference: the builder runs as ubuntu (uid 1000) because the upstream ubuntu:24.04 base image ships a pre-existing ubuntu:ubuntu account at uid 1000, and build.yml distro.ubuntu.base_user adopts it.

Lives in the overthinkos/ubuntu repo (git submodule at box/ubuntu). Build it from the submodule: charly -C box/ubuntu box build ubuntu-builder (normally builds implicitly as a dependency of ubuntu-coder). Its pixi/nodejs/build-toolchain candies are pulled by github reference from the main repo.

Box Properties

| Property | Value | |----------|-------| | Base | ubuntu (which = ubuntu:24.04 + our bootstrap) | | Layers | pixi, nodejs, build-toolchain | | Platforms | linux/amd64 | | Registry | ghcr.io/overthinkos | | User | ubuntu / uid 1000 (adopt mode — see /charly-image:image "user_policy") | | Home | /home/ubuntu |

Full candy stack

1. /charly-distros:ubuntu — Ubuntu 24.04 + bootstrap. Inherits Debian's apt-get update && apt-get install -y --no-install-recommends curl ca-certificates gnupg pattern because build.yml distro.ubuntu declares inherits: debian. Ubuntu-specific: base_user: { name: ubuntu, uid: 1000, gid: 1000, home: /home/ubuntu } — no useradd step emitted.
2. /charly-languages:pixi — pixi package manager + env paths (/home/ubuntu/.pixi).
3. /charly-coder:nodejs — Node.js + npm (generic nodejs).
4. /charly-coder:build-toolchain — same Debian -dev packages as /charly-distros:debian-builder.

Adopt-mode semantics

When the generator emits the Containerfile for this image, the bootstrap section contains:

# User ubuntu (uid=1000) adopted from base image (declared in build.yml distro.base_user) — no useradd needed
WORKDIR /home/ubuntu
USER 1000

No useradd, no groupadd, no usermod -l rename. The upstream ubuntu:ubuntu account is honored verbatim — HOME, npm prefix, pixi env, cargo home, sudoers all derive from resolved.User = "ubuntu". See /charly-image:image "user_policy" and /charly-internals:generate-source "writeBootstrap".

Role in the build system

Declares builds: [pixi, npm, cargo] and is referenced from ubuntu: as:

ubuntu:
  builder:
    pixi: ubuntu-builder
    npm: ubuntu-builder
    cargo: ubuntu-builder

During charly box build ubuntu-coder, cargo/npm/pixi-owning candies get their FROM ubuntu-builder AS <layer>-<type>-build stages from this image, then COPY --from=<stage> --chown=1000:1000 /home/ubuntu /home/ubuntu into the final ubuntu-coder. (The --chown=1000:1000 numeric form works uniformly regardless of user name — see /charly-coder:build-toolchain for the builder-artifact COPY pattern.)

Cross-distro sibling builders

• /charly-distros:fedora-builder — RPM-family, user:user uid 1000 (create).
• /charly-distros:debian-builder — deb-family, Debian 13, user:user (create — Debian 13 ships no pre-existing uid-1000 user).
• /charly-distros:arch-builder — pacman-family, user:user + yay for AUR.

The three builders have near-identical candy stacks (pixi + nodejs + build-toolchain). The only meaningful divergence is this box's adopt-mode ubuntu:ubuntu identity.

Quick start

charly -C box/ubuntu box build ubuntu-builder
charly shell ubuntu-builder               # drops you into /home/ubuntu as uid 1000
id                                    # uid=1000(ubuntu) gid=1000(ubuntu)

Typically not invoked directly — it's a build-time dependency of /charly-coder:ubuntu-coder.

Verification

• charly -C box/ubuntu box list | grep ubuntu-builder
• charly shell ubuntu-builder -- id → uid=1000(ubuntu) gid=1000(ubuntu)
• charly shell ubuntu-builder -- pixi --version && node --version && gcc --version

Related boxes

• /charly-distros:ubuntu — parent base; declares base_user: in build.yml.
• /charly-coder:ubuntu-coder — the consumer that this builder serves.
• /charly-distros:debian-builder — deb-family sibling without adopt mode.
• /charly-distros:fedora-builder — canonical RPM-family sibling.

Related candies

• /charly-languages:pixi, /charly-coder:nodejs, /charly-coder:build-toolchain

Related commands

• /charly-build:build — base_user: declaration format in build.yml distro.*
• /charly-image:image — user_policy: field (auto / adopt / create) and the decision table
• /charly-build:generate — adopt-vs-create writeBootstrap emission modes

When to use this skill

MUST be invoked when:

• Building or troubleshooting ubuntu-builder itself.
• Debugging multi-stage COPY-from errors or permission issues in a ubuntu-coder build (this is the source stage; uid 1000 = ubuntu by adoption).
• Understanding why ${HOME} = /home/ubuntu (not /home/user) inside builder stages.