Chapter 03: Ubuntu Base Image and OS Standards

Word target: 3,500
Primary deliverable: Ubuntu baseline profile and cloud-init template
Key diagrams: Image lifecycle pipeline

Learning Goals

  • Standardize Ubuntu 24.04 server baseline configuration.
  • Use cloud-init for reproducible first-boot provisioning.
  • Establish OS hardening and patching defaults.

MVP Lab Worksheet

  • Objective: Build Ubuntu baseline checklist.
  • Starting state: Fresh Ubuntu VM.
  • Steps:
    1. Configure users, SSH keys, timezone, and NTP.
    2. Enable unattended upgrades and essential packages.
    3. Capture baseline cloud-init file.
  • Evidence: Baseline checklist + cloud-init YAML.
  • Exit criteria: Reproducible VM bootstrap in under 10 minutes.
  • Rollback: Revert to clean snapshot and rerun bootstrap.

Advanced Lab Worksheet

  • Objective: Versioned image pipeline.
  • Starting state: MVP bootstrap validated.
  • Steps:
    1. Build golden image version tags.
    2. Add automated validation tests.
    3. Add deprecation policy for old images.
  • Evidence: Image catalog with validation status.
  • Exit criteria: Repeatable image release workflow.
  • Rollback: Promote prior image version.
Ubuntu Focus

Explicitly document: cloud-init, systemd, netplan, ufw, apt, unattended-upgrades.