# Enterprise Infrastructure Simulator

## Problem Statement

Infrastructure teams need a safe place to rehearse lifecycle operations before applying them to production fleets. Patch windows, hardening changes, scale events, and node failures all carry operational risk when they are tested only during real incidents.

## Solution Overview

This project models common Linux infrastructure operations with Ansible playbooks and shell-based simulations. It keeps the automation readable and auditable while producing example evidence that resembles a real change record.

## Architecture Overview

```
Operator -> Make/CLI -> Ansible Inventory -> Playbooks -> Linux Nodes
                         |                  |
                         v                  v
                    Scenarios          Reports/Logs
```

Core components:

- `inventory/hosts.ini` defines managed node groups.
- `playbooks/` contains provisioning, patching, hardening, and decommissioning workflows.
- `scripts/` injects scaling and failure conditions.
- `scenarios/` documents operational exercises.
- `examples/` stores representative outputs for review.

## How to Run

```bash
cd enterprise-infra-simulator

# Validate playbook syntax.
make test

# Provision the simulated estate.
make run

# Apply security patches.
make patch

# Apply host hardening.
make harden

# Run the failure and patch demo.
make demo
```

Direct Ansible commands are also supported:

```bash
ansible-playbook -i inventory/hosts.ini playbooks/provision.yml
ansible-playbook -i inventory/hosts.ini playbooks/patch.yml
ansible-playbook -i inventory/hosts.ini playbooks/hardening.yml
```

## Example Output

```text
PLAY RECAP *********************************************************************
web01  : ok=21 changed=7 unreachable=0 failed=0 skipped=3 rescued=0 ignored=1
db01   : ok=18 changed=4 unreachable=0 failed=0 skipped=5 rescued=0 ignored=1
lb01   : ok=16 changed=3 unreachable=0 failed=0 skipped=6 rescued=0 ignored=0

Patch status: SUCCESS
Updates applied: 12
Reboot required: false
```

Additional sample evidence is available in [examples/patch-output.txt](examples/patch-output.txt) and [examples/failure-simulation.txt](examples/failure-simulation.txt).

## Real-World Use Case

A platform team can use this project to demonstrate how routine operating procedures are encoded, reviewed, and tested before production change windows. The same patterns apply to regulated Linux estates where patch evidence, hardening controls, and incident drills must be repeatable.