chore: slim down agent container image using node:22-bookworm-slim

[Copilot]

Reduce agent container image size by ~40% (669MB → 404MB) by switching to a leaner base image and removing unnecessary packages.

Changes

• Base image: ubuntu:22.04 → node:22-bookworm-slim (Node.js 22/npm/npx pre-installed)
• Docker CLI: Multi-stage copy from docker:27.4.1-cli instead of apt install (avoids curl/gnupg deps)
• Removed packages: dnsutils, net-tools, netcat-openbsd, curl, gnupg (none used in scripts)
• Kept packages: iptables, git, ca-certificates

FROM node:22-bookworm-slim

# Copy Docker CLI from official image (no network deps)
COPY --from=docker:27.4.1-cli /usr/local/bin/docker /usr/local/bin/docker

RUN apt-get update && \
    apt-get install -y --no-install-recommends \
    iptables git ca-certificates && \
    apt-get clean && rm -rf /var/lib/apt/lists/*

Image	Size
Previous	669MB
New	404MB

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• squid-proxy
  • Triggering command: /usr/bin/getent getent hosts squid-proxy (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

Slim down the agent container image and probably the only deps we need are npx / node / python and docker

first consider if the base image could be replaced with something lightweight

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[github-actions]

Test Coverage Report

Metric	Coverage	Covered/Total
Lines	67.21%	695/1034
Statements	67.35%	716/1063
Functions	70.24%	85/121
Branches	62.46%	228/365

Coverage Thresholds

The project has the following coverage thresholds configured:

• Lines: 38%
• Statements: 38%
• Functions: 35%
• Branches: 30%

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Coverage report generated by `npm run test:coverage`