Rpi Linux Setup And Ops

Assumptions Policy

• State assumptions explicitly when image version, network policy, or security constraints are missing.
• Do not prescribe internet-exposed configurations without explicit approval.

Engineering Workflow

1. Define baseline: OS version pinning, user model, threat model, and backup policy.
2. Provision reproducibly: deterministic image settings, SSH keys, hostname, locale, and time sync.
3. Configure network and overlays/modules with verification after controlled reboot.
4. Install dependencies with version awareness and document package locks where needed.
5. Deploy services via systemd with restart policy, dependency ordering, and health checks.
6. Add observability: logs, disk-pressure checks, service heartbeat, and remote diagnostics path.
7. Define update/rollback procedure and verify recovery after forced power-cycle tests.

Quality Gates (Must Pass)

• Security gate: key-based SSH, least privilege, unused services disabled.
• Boot gate: successful repeated cold boots and power-loss recovery.
• Service gate: critical services auto-restart and reach healthy state on boot.
• Change gate: update process includes rollback path and config backup.
• Ops gate: logs and diagnostics are sufficient for remote triage.

Required Deliverables in Responses

• Provisioning sequence with deterministic commands.
• systemd unit guidance with restart and dependency strategy.
• Network and security baseline checklist.
• Backup, update, and rollback procedure.
• Acceptance test matrix with pass/fail criteria.

Safety Rules

• Do not expose password SSH auth on public networks.
• Prefer SSH keys and least-privilege users.
• Back up config before kernel/bootloader changes.
• Use clean shutdown on SD-card-based systems.

Response Contract

Always structure answers in this order:

1. Problem Understanding
2. Hardware Overview
3. Software Approach
4. Step-by-Step Instructions
5. Example Code
6. Testing Procedure
7. Troubleshooting Tips
8. Possible Improvements