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Tim Reilly - Field Notes and Resource Links

A small, public-safe set of links I often share in conversations about field engineering, architecture discovery, domain modeling, and moving from discussion to buildable systems.

Event Storming and Domain Modeling

• Introducing EventStorming - the canonical book reference.
• Hands-On Domain-Driven Design with .NET Core - Alexey Zimarev's practical DDD book/code repo. Chapter 3 is especially useful as an Event Storming bridge: start with collaborative discovery, capture events/commands/policies in the language of the domain, then use that shared model to shape bounded contexts and implementation seams.
• Domain-Driven Design Quickly - concise DDD primer.
• DDD Reference - Eric Evans' compact reference for DDD terms and p

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DNS Behavior with APIM + VNet + Private DNS + Custom DNS

Summary

After introducing Private DNS zones into a VNet-integrated environment with custom DNS servers, DNS resolution behavior changes due to zone precedence and authority rules.

This can result in previously working DNS lookups failing, not because DNS is broken, but because resolution is being intercepted earlier in the lookup chain.

---

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#!/usr/bin/env pwsh

Write-Host "=== Azure Bastion Connection Helper ===" -ForegroundColor Cyan
Write-Host ""

# Step 1: Get all VMs with their bastion-related info
Write-Host "Loading VMs and Bastions..." -ForegroundColor Yellow
$vms = az vm list -d --query "[].{Name:name, ResourceGroup:resourceGroup, PowerState:powerState, VnetId:networkProfile.networkInterfaces[0].id}" | ConvertFrom-Json

if ($vms.Count -eq 0) {

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#!/bin/bash

# Script to remove all Zone.Identifier files from the directory
# These files are Windows metadata files created when downloading from the internet

echo "Searching for Zone.Identifier files in directory..."

# Find and count Zone.Identifier files
ZONE_FILES=$(find . -name "*:Zone.Identifier" -type f)
COUNT=$(echo "$ZONE_FILES" | grep -c "Zone.Identifier" 2>/dev/null || echo "0")

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Local DB Configuration and Introduction

TLDR: run migrations against new db and set environment variables:

Add this from sample.env to env with accurate db names, user and passwords:

POSTGRES_HOST=localhost
POSTGRES_PORT=5432
POSTGRES_DB=sqfour

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# Unix
echo "=== Quick System Check ===" && top -bn1 | grep "Cpu" | awk '{print "CPU Used: " 100-$8 "%"}' && free -h | grep "Mem" | awk '{print "Memory: " $3 "/" $2 " (" int($3/$2*100) "%)"}' && echo "Load: $(uptime | awk -F'load average:' '{print $2}')"

# Windows Powershell
$cpu = (Get-CimInstance Win32_Processor | Measure-Object LoadPercentage -Average).Average; $mem = Get-CimInstance Win32_OperatingSystem; $memPct = [math]::Round(($mem.TotalVisibleMemorySize - $mem.FreePhysicalMemory) / $mem.TotalVisibleMemorySize * 100, 1); Write-Host "CPU: $cpu% | Mem: $memPct% | Uptime: $((Get-Date) - $mem.LastBootUpTime | ForEach-Object {"$($_.Days)d $($_.Hours)h"})" -ForegroundColor Cyan

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provider "azurerm" {
  features {
    resource_group {
      prevent_deletion_if_contains_resources = false 
    }
  }
}

variable "prefix" {
    description = "Prefix for the resources (rock1)"

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Let's get it going manually...

First, let's set some parameters

vars

UNIQUE="chi2"
LOCATION=westus2

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Network Gismos!

https://aka.ms/NetworkGizmos

Hello! Thank you for coming! We're going to look at three different tools for inspecting our networks!

The first tool we'll use is called nmap, you can install it for unix environments or windows. It's a command line tool for assessing serviceable ports in networks. It is also helpful for groking network subneting and cidr notation.

Let's see what we get when we query some IP address...

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"""
you're in the python debug terminal and you need to export some pydantic models for 
"""

with open("data_point.json", "w") as file:
    file.write(data_point.json())
    
    
with open("model_data.json", "w") as file:
    file.write(results.json())