MAINT: Optimize devcontainer Dockerfile

[spencrr]

Description

Optimizes the devcontainer Dockerfile to improve build speed, reduce image size, and tighten permissions.

Key changes:

Build performance

• Use BuildKit cache mounts (--mount=type=cache) for all apt-get layers instead of apt-get clean && rm -rf /var/lib/apt/lists/* — cached packages persist across local rebuilds, so subsequent builds skip re-downloading unchanged packages. Note: these mounts only benefit local builds; in CI, GHA layer caching (cache-from: type=gha) handles caching at the layer level.
• The apt-get clean && rm -rf /var/lib/apt/lists/* cleanup commands are removed because BuildKit cache mounts store apt data outside the image layer, so nothing needs to be cleaned up — the layer never contains it.
• Install uv via COPY --from=ghcr.io/astral-sh/uv:0.10.8 multi-stage copy instead of curl | sh — avoids a network round-trip, shell pipe execution, and the extra cleanup of /root/.local/bin.

Image size

• Apply --no-install-recommends consistently to all apt-get install invocations (previously only used on the Speech SDK block) — prevents pulling in unnecessary Recommends dependencies (e.g., X11 libs, man pages).

Reproducibility

• Pin base image to python:3.11-bookworm instead of python:3.11 — prevents silent shifts between Debian releases (e.g., Bookworm to Trixie) when the base image is updated. (and match existing bookworm apt repo call)
• Pin uv to a specific version (0.10.8) via multi-stage COPY --from — the previous curl | sh always fetched the latest release, making builds non-deterministic.
• Set DEBIAN_FRONTEND=noninteractive as a global ENV instead of inline per-command — prevents any apt-get invocation from prompting for interactive input.

Security hardening

• Change chmod 777 to chmod 755 for all cache directories (pip, pylance, venv, uv, mypy) — 777 is unnecessarily permissive in a single-user devcontainer where vscode owns these directories.
• Removed unecessary shebang from scripts that were always called with python script_name.py to avoid precommit complaint.

Dependency cleanup

• Drop redundant apt-transport-https from explicit install — this is a transitional no-op package on Debian Bookworm (HTTPS support is built into apt natively). The base image already includes it.
• Drop redundant lsb-release from explicit install — the base image already includes it
• Remove stale rm -rf /opt/venv and debug ls -la /opt/venv/bin/activate from the uv/venv setup step.

Node.js

• Bump to Node.js 24.x (LTS), move npm install -g @github/copilot to a devcontainer feature to remove unecessary tool from production builds.

Minor cleanup

• Fix trailing whitespace on chmod line and indentation on "Set cache directories" comment.

Tests and Documentation

• No code or API changes — this only affects the devcontainer build infrastructure.
• Verified the Dockerfile builds successfully.
• No JupyText changes needed.

[Copilot]

Pull request overview

This PR optimizes the development container and related tooling scripts to improve devcontainer build performance, reduce image size, and tighten default permissions while updating Node.js expectations.

Changes:

• Updated .devcontainer/Dockerfile to use a pinned Bookworm base image, BuildKit apt cache mounts, --no-install-recommends, multi-stage uv install, and Node.js 24.x.
• Tightened cache directory permissions (e.g., mypy cache, various .cache/* directories) from 777 to 755.
• Moved CLI installs into devcontainer features and updated packaging guidance to expect Node.js 24.x.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
.devcontainer/Dockerfile	BuildKit caching, pinned base image, uv multi-stage install, Node.js 24.x, and permission tightening.
.devcontainer/devcontainer.json	Adds devcontainer features (Azure CLI, Copilot CLI).
.devcontainer/devcontainer_setup.sh	Tightens mypy cache permissions and keeps devcontainer setup behavior.
build_scripts/prepare_package.py	Removes shebang and updates Node.js version guidance in error output.
docker/build_pyrit_docker.py	Removes shebang (script intended to be run via python ...).
docker/run_pyrit_docker.py	Removes shebang (script intended to be run via python ...).

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[Copilot]

When using --mount=type=cache for apt directories, concurrent builds can contend on apt lock files stored inside the shared cache (and occasionally corrupt the cache). It’s safer to set sharing=locked on these cache mounts (and mount the more specific .../apt/lists path) to avoid intermittent build failures when multiple builds run in parallel.

[Copilot]

Using "version": "latest" for devcontainer features makes devcontainer builds non-reproducible and can introduce breaking changes without a PR. Pin these features to a specific, known-good version (or a semver range you’re comfortable with) to align with the PR’s reproducibility goals.

Suggested change

	"ghcr.io/devcontainers/features/azure-cli:1": {
	"version": "latest"
	},
	"ghcr.io/devcontainers/features/copilot-cli:1": {
	"version": "latest"
	}
	"ghcr.io/devcontainers/features/azure-cli:1": {},
	"ghcr.io/devcontainers/features/copilot-cli:1": {}

[Copilot]

This Dockerfile now relies on BuildKit-only RUN --mount=type=cache syntax. If BuildKit is disabled (or an older Dockerfile frontend is used), the build will fail parsing these RUN lines. Consider adding a # syntax=docker/dockerfile:<version> directive at the top (and/or ensuring the build entrypoints set DOCKER_BUILDKIT=1) so the devcontainer build works reliably across environments.

[Copilot]

The curl -fsSL https://deb.nodesource.com/setup_24.x | bash - pattern downloads and executes a remote script as root without any integrity or authenticity verification, creating a supply-chain risk. If the NodeSource endpoint or DNS is compromised, an attacker could run arbitrary code during the image build and persist backdoored tooling into the devcontainer image. Replace this pipe-to-bash installer with a method that verifies a pinned script or package (e.g., manually configuring the APT repository with a GPG key or verifying a checksum/signature before execution).

[romanlutz]

Switching from 18 to 24 there could be a lot of changes. If that's absolutely needed right now I'd defer until later because it could significantly slow down ongoing front end work that was built with 18.

[spencrr]

@romanlutz I can pull this change out, but Node 20 is EOL April 2026