### Quick Start: Initialize and Configure Starter Kit

Source: https://thedecipherist.com/articles/claude-code-mastery-project-starter-kit

This section outlines the initial steps to get started with the starter kit. It includes cloning the repository, initializing a new Git repository, installing global configurations, setting up the project, and starting the development environment. It also covers converting an existing project to use the starter kit.

```bash
# 1. Clone
git clone https://github.com/TheDecipherist/claude-code-mastery-project-starter-kit my-project
cd my-project && rm -rf .git && git init

# 2. Install global config (one-time, never overwrites existing)
claude /install-global

# 3. Configure your project
claude /setup

# 4. Start building
claude
```

```bash
claude "/convert-project-to-starter-kit ~/my-existing-project"
```

--------------------------------

### Example .env.example File for Project Setup

Source: https://thedecipherist.com/articles/the_docker_developer_workflow_guide_2026

An example `.env.example` file demonstrating how to define required environment variables with placeholder values. Committing this file to version control helps new team members set up their local development environment correctly.

```dotenv
# .env.example (committed to git)
POSTGRES_USER=myapp
POSTGRES_PASSWORD=change_me_locally
POSTGRES_DB=myapp_dev
NODE_ENV=development
REDIS_URL=redis://redis:6379
JWT_SECRET=any_random_string_for_dev
```

--------------------------------

### Automated MongoDB Setup and Initialization

Source: https://thedecipherist.com/articles/the-mongo-replicaset-guide

Commands to prepare the environment, execute the installation script, and configure replica set nodes. These commands handle directory creation, permission management, and service execution.

```bash
# Create a directory for MongoDB setup files
mkdir -p mongodb-setup && cd mongodb-setup

# Create the installation script
nano mongodb-install.sh

# Make executable
chmod +x mongodb-install.sh

# Run with sudo
sudo ./mongodb-install.sh
```

--------------------------------

### StrictDB Basic Usage Example (Node.js)

Source: https://thedecipherist.com/articles/strictDB

A quick start example demonstrating how to initialize StrictDB, discover schemas, perform read and write operations, update, delete, and inspect query plans. It covers the essential workflow for interacting with a database via StrictDB.

```javascript
import { StrictDB } from 'strictdb';

const db = await StrictDB.create({ uri: process.env.DATABASE_URL });

// Discover
const schema = await db.describe('users');

// Read
const user = await db.queryOne('users', { email: 'tim@example.com' });

// Write
const receipt = await db.insertOne('users', { email: 'new@example.com', name: 'New User' });

// Update
await db.updateOne('users', { email: 'tim@example.com' }, { $set: { role: 'admin' } });

// Delete
await db.deleteOne('users', { email: 'old@example.com' });

// What runs under the hood
const plan = await db.explain('users', { filter: { role: 'admin' }, limit: 50 });

await db.close();
```

--------------------------------

### Start Service with Fixed Port

Source: https://thedecipherist.com/articles/claude-code-guide-v5

Demonstrates how to explicitly define a port when starting a development server to avoid default port conflicts.

```bash
# CORRECT
npx next dev -p 3002

# WRONG - never let it default
npx next dev
```

--------------------------------

### Install PaaS Platforms via Shell Script

Source: https://thedecipherist.com/articles/docker-swarm-guide

Installation commands for self-hosted PaaS solutions Dokploy and Coolify using their respective bootstrap scripts.

```bash
# Install Dokploy
curl -sSL https://dokploy.com/install.sh | sh

# Install Coolify
curl -fsSL https://cdn.coollabs.io/coolify/install.sh | bash
```

--------------------------------

### RuleCatch MCP Server Setup (JSON)

Source: https://thedecipherist.com/articles/rulecatch

This JSON configuration sets up the RuleCatch MCP server. It specifies the command to run ('npx'), arguments for installation ('-y', '@rulecatch/mcp-server'), and environment variables for API key and region.

```json
{
  "mcpServers": {
    "rulecatch": {
      "command": "npx",
      "args": ["-y", "@rulecatch/mcp-server"],
      "env": {
        "RULECATCH_API_KEY": "rc_your_key",
        "RULECATCH_REGION": "us"
      }
    }
  }
}
```

--------------------------------

### Start Multi-Service Development Environment

Source: https://thedecipherist.com/articles/claude-code-guide-v5

A template for starting multiple services simultaneously with assigned ports and environment variables, ensuring previous instances are terminated first.

```bash
# ALWAYS kill first
lsof -ti:4000,4010,4020,4030,4040 | xargs kill -9 2>/dev/null

# Then start
PORT=4000 pnpm --filter website dev &
PORT=4010 pnpm --filter api dev &
PORT=4020 pnpm --filter dashboard dev &
PORT=4030 NEXT_PUBLIC_APP_MODE=admin pnpm --filter dashboard dev &
PORT=4040 pnpm --filter analytics dev &
```

--------------------------------

### Node.js Docker Build Stage Setup

Source: https://thedecipherist.com/articles/the_docker_developer_workflow_guide_2026

This Dockerfile stage installs build tools like python3, make, and g++ required for compiling native Node.js modules. It then copies package.json and package-lock.json to leverage Docker's layer caching for efficient dependency installation using 'npm ci --omit=dev'. Build tools are removed before the next stage.

```dockerfile
FROM node:20-bookworm-slim AS builder

WORKDIR /app

# Install the construction equipment.
# python3, make, and g++ are needed because packages like
# bcrypt and sharp contain C/C++ code that must be compiled
# during npm install. These tools are ~300MB. They will NOT
# be in our final image.
RUN apt-get update && \
    apt-get install -y --no-install-recommends \
    python3 \
    make \
    g++ \
    && apt-get clean && \
    rm -rf /var/lib/apt/lists/*

# Copy ONLY the package files first.
# Why not copy everything? Because of layer caching.
# Docker caches each layer. If nothing in this layer changed
# (same package.json, same lock file), Docker reuses the cache
# and skips the expensive npm install below.
# If we copied ALL source code here, changing one line of
# JavaScript would invalidate this cache and force a full
# npm install every single time.
COPY package.json package-lock.json ./

# Install ONLY production dependencies.
# --omit=dev means: skip jest, eslint, nodemon, prettier,
# and every other devDependency. They're for your laptop,
# not for production.
# npm ci (clean install) is faster and more reliable than
# npm install - it deletes node_modules first and installs
# exactly what's in the lock file.
RUN npm ci --omit=dev

# At this point, this stage has:
# Yes Compiled, production-ready node_modules
# No python3, make, g++ (300+ MB of build tools)
# No apt cache and package lists
# We want the node_modules. We don't want anything else.
```

--------------------------------

### Install Docker Engine on Ubuntu

Source: https://thedecipherist.com/articles/docker-swarm-guide

Removes legacy packages, configures the official Docker repository, and installs the latest Docker Engine, CLI, and Compose plugins.

```bash
for pkg in docker.io docker-doc docker-compose docker-compose-v2 podman-docker containerd runc; do
    sudo apt-get remove $pkg
done

sudo apt-get update
sudo apt-get install ca-certificates curl gnupg
sudo install -m 0755 -d /etc/apt/keyrings
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /etc/apt/keyrings/docker.gpg
sudo chmod a+r /etc/apt/keyrings/docker.gpg

echo "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.gpg] https://download.docker.com/linux/ubuntu $(. /etc/os-release && echo "$VERSION_CODENAME") stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null

sudo apt-get update
sudo apt-get install docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin

sudo groupadd docker
sudo usermod -aG docker $USER
```

--------------------------------

### Combine apt-get Install Commands in Dockerfile

Source: https://thedecipherist.com/articles/the_docker_developer_workflow_guide_2026

Reduces Docker image layers by consolidating multiple `apt-get install` commands into a single `RUN` instruction. This improves build cache efficiency and reduces the overall image size by performing updates, installations, and cleanup within one layer.

```dockerfile
RUN apt-get update && \
    apt-get install -y --no-install-recommends python3 make g++ && \
    rm -rf /var/lib/apt/lists/*
```

--------------------------------

### Multi-Stage Dockerfile for Non-Root User Production Build

Source: https://thedecipherist.com/articles/the_docker_developer_workflow_guide_2026

This multi-stage Dockerfile demonstrates building a Node.js application. The first stage ('builder') runs as root to install build tools and dependencies. The second stage starts from a clean Node.js image, copies artifacts from the builder stage, sets ownership to the 'node' user, switches to the 'node' user, and exposes port 3000. The application is then run using 'node server.js'.

```dockerfile
# Stage 1: Build as root (needs compiler tools)
FROM node:20-bookworm-slim AS builder
WORKDIR /app
RUN apt-get update && apt-get install -y python3 make g++ && \
    apt-get clean && rm -rf /var/lib/apt/lists/*
COPY package.json package-lock.json ./
RUN npm ci --omit=dev

# Stage 2: Production as non-root
FROM node:20-bookworm-slim
WORKDIR /app
ENV NODE_ENV=production

COPY --from=builder --chown=node:node /app/node_modules ./node_modules
COPY --chown=node:node . .

USER node
EXPOSE 3000
ENTRYPOINT ["node", "server.js"]
```

--------------------------------

### Install StrictDB and Database Drivers (Node.js)

Source: https://thedecipherist.com/articles/strictDB

This snippet shows how to install the core StrictDB package and common database drivers using npm. Users should install only the drivers they intend to use, as they are optional peer dependencies.

```bash
npm install strictdb

# Install whatever driver(s) you need
npm install mongodb   # MongoDB
npm install pg        # PostgreSQL
npm install mysql2    # MySQL
```

--------------------------------

### Install DNS Utilities for Debian/Alpine

Source: https://thedecipherist.com/articles/the_docker_developer_workflow_guide_2026

Installs DNS resolution utilities required for network troubleshooting. 'dnsutils' is for Debian-based systems, and 'bind-tools' is for Alpine Linux.

```bash
# Debian
apt-get update && apt-get install -y dnsutils

# Alpine
apk add bind-tools
```

--------------------------------

### MongoDB 8.0 Production Installation Script (Bash)

Source: https://thedecipherist.com/articles/the-mongo-replicaset-guide

A bash script designed for automated installation and configuration of MongoDB 8.0 on Ubuntu 22.04/24.04. It includes sections for node configuration, data drive setup, security settings, and replica set initialization. Users must edit the CONFIGURATION section before execution.

```bash
#!/bin/bash
#===============================================================================
# MongoDB 8.0 Production-Ready Installation Script
# 
# This script automates the installation and configuration of MongoDB 8.0
# following production best practices for Ubuntu 22.04/24.04.
#
# Usage:
#   1. Edit the CONFIGURATION section below
#   2. Run: sudo bash mongodb-install.sh
#===============================================================================

set -e  # Exit on any error

#===============================================================================
# CONFIGURATION - EDIT THESE VALUES
#===============================================================================

# Node Configuration
NODE_HOSTNAME="mongodb1.yourdomain.com"    # This node's FQDN
NODE_IP="10.10.1.122"                       # This node's private IP
REPLICA_SET_NAME="rs0"                      # Replica set name

# Other Replica Set Members (for /etc/hosts)
OTHER_NODES=(
    "10.10.1.175 mongodb2.yourdomain.com mongodb2"
    "10.10.1.136 mongodb3.yourdomain.com mongodb3"
)

# Data Drive Configuration
DATA_DRIVE="/dev/nvme1n1"                   # Set to "" to skip formatting
DATA_PATH="/data/mongodb"

# MongoDB Configuration
MONGODB_VERSION="8.0"
WIREDTIGER_CACHE_GB="2"                     # 50% of RAM - 1GB recommended
MONGODB_PORT="27017"

# Security
GENERATE_KEYFILE="true"
KEYFILE_PATH="/keys/mongodb.key"

# Admin User (leave ADMIN_PASSWORD empty to skip)
ADMIN_USER="adminUser"
ADMIN_PASSWORD=""

# Replica Set Init (set true only on PRIMARY, after all nodes installed)
INIT_REPLICA_SET="false"
NODE_PRIORITY="2"

#===============================================================================
# COLOR OUTPUT
#===============================================================================

RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m'

log_info() { echo -e "${BLUE}[INFO]${NC} $1"; }
log_success() { echo -e "${GREEN}[SUCCESS]${NC} $1"; }
log_warn() { echo -e "${YELLOW}[WARNING]${NC} $1"; }
log_error() { echo -e "${RED}[ERROR]${NC} $1"; }

#===============================================================================
# PRE-FLIGHT CHECKS
#===============================================================================

preflight_checks() {
    log_info "Running pre-flight checks..."

    if [[ $EUID -ne 0 ]]; then
        log_error "This script must be run as root (use sudo)"
        exit 1
    fi

    if [[ -f /etc/os-release ]]; then
        . /etc/os-release
        if [[ "$ID" != "ubuntu" ]]; then
            log_error "This script is designed for Ubuntu. Detected: $ID"
            exit 1
        fi
        log_success "Ubuntu $VERSION_ID detected"
    fi

    if [[ -n "$DATA_DRIVE" && ! -b "$DATA_DRIVE" ]]; then
        log_error "Data drive $DATA_DRIVE not found!"
        lsblk
        exit 1
    fi

    if ! ping -c 1 repo.mongodb.org &> /dev/null; then
        log_error "Cannot reach repo.mongodb.org"
        exit 1
    fi

    log_success "Pre-flight checks passed"
}

#===============================================================================
# HOSTNAME CONFIGURATION
#===============================================================================

configure_hostname() {
    log_info "Configuring hostname..."
    hostnamectl set-hostname "$NODE_HOSTNAME"
    
    sed -i '/mongodb[0-9]/d' /etc/hosts
    echo "$NODE_IP $NODE_HOSTNAME ${NODE_HOSTNAME%%.*}" >> /etc/hosts
    for node in "${OTHER_NODES[@]}"; do
        echo "$node" >> /etc/hosts
    done

    log_success "Hostname configured: $NODE_HOSTNAME"
}

#===============================================================================

```

--------------------------------

### Start and Enable MongoDB Service

Source: https://thedecipherist.com/articles/the-mongo-replicaset-guide

Starts the MongoDB service, enables it to start automatically on boot, and checks its current status. This ensures MongoDB is running and persistent.

```shell
sudo systemctl start mongod
sudo systemctl enable mongod
sudo systemctl status mongod
```

--------------------------------

### Install MongoDB Server

Source: https://thedecipherist.com/articles/the-mongo-replicaset-guide

Updates the package list and installs the MongoDB server package. This command ensures that the latest available version from the added repository is installed.

```shell
sudo apt-get update
sudo apt-get install -y mongodb-org
```

--------------------------------

### Install Dockge Docker Compose Manager

Source: https://thedecipherist.com/articles/docker-swarm-guide

Installs Dockge, a lightweight Docker Compose stack manager. This involves creating directories, downloading the compose file, and starting the service using Docker Compose.

```bash
mkdir -p /opt/stacks /opt/dockge
cd /opt/dockge
curl -O https://raw.githubusercontent.com/louislam/dockge/master/compose.yaml
docker compose up -d
```

--------------------------------

### Complete Docker Deployment Script Example

Source: https://thedecipherist.com/articles/docker-swarm-guide

A comprehensive bash script for building and deploying Docker services. It reads version information, exports environment variables, builds images using Docker Compose, and deploys the stack.

```bash
#!/bin/bash
set -e

# Configuration
REGISTRY="yourregistry"
SERVICE="nodeserver"
COMPOSE_FILE="docker-compose.yml"

# Read version
BUILD_VERSION=$(cat ./globals/_versioning/buildVersion.txt)
LONG_COMMIT=$(git rev-parse HEAD)
SHORT_COMMIT=$(git rev-parse --short HEAD)

# Export for docker-compose
export BUILD_VERSION
export LONG_COMMIT
export DOCKER_BUILD_VERSION="${BUILD_VERSION}"

echo "Building version ${BUILD_VERSION} (commit: ${SHORT_COMMIT})"

# Build images
docker compose -f $COMPOSE_FILE build
```

--------------------------------

### Docker Init: Generate Docker Configuration Files

Source: https://thedecipherist.com/articles/the_docker_developer_workflow_guide_2026

Initializes a Dockerfile, docker-compose.yml, and .dockerignore file tailored to your project's detected language or framework. It provides a starting point for containerizing your application. Run this command in your project's root directory.

```bash
docker init
```

--------------------------------

### Update System Packages on Ubuntu

Source: https://thedecipherist.com/articles/the-mongo-replicaset-guide

Updates the package list and upgrades installed packages on Ubuntu systems. This is a standard maintenance step before installing new software.

```bash
sudo apt-get update && sudo apt-get upgrade -y
```

--------------------------------

### GET /db/getProfilingStatus

Source: https://thedecipherist.com/articles/the-mongo-replicaset-guide

Retrieves the current profiling configuration for the active database.

```APIDOC
## GET /db/getProfilingStatus

### Description
Returns the current profiling status, including the active level, the slow query threshold, and the sampling rate.

### Method
GET

### Response
#### Success Response (200)
- **was** (integer) - Current profiling level.
- **slowms** (integer) - Threshold in milliseconds for slow queries.
- **sampleRate** (float) - The fraction of slow operations to record.

#### Response Example
{
  "was": 1,
  "slowms": 100,
  "sampleRate": 1.0
}
```

--------------------------------

### Initialize Multi-Stage Docker Build

Source: https://thedecipherist.com/articles/the_docker_developer_workflow_guide_2026

The starting syntax for a multi-stage Docker build, which allows for separating build-time tools from the final production image.

```dockerfile
# syntax=docker/dockerfile:1

# ============================================
# STAGE 1: The construction zone
# This stage exists ONLY to compile dependencies.
# Nothing from this stage ships in the final image
# except what we explicitly copy out.
```

--------------------------------

### Install XFS Filesystem Tools

Source: https://thedecipherist.com/articles/the-mongo-replicaset-guide

Installs the `xfsprogs` package, which provides utilities for managing XFS filesystems. XFS is recommended for MongoDB's WiredTiger storage engine for better performance.

```bash
sudo apt-get install xfsprogs -y
```

--------------------------------

### Correct CI/CD Deployment Pattern (Docker Image)

Source: https://thedecipherist.com/articles/the_docker_developer_workflow_guide_2026

This snippet illustrates the recommended CI/CD deployment pattern using Docker. The CI environment handles building and pushing the Docker image to a registry. The deployment step then connects to the production server and instructs it to update the service with the new image. This ensures that all build and compilation steps occur in the CI environment, not on the production server.

```yaml
# The RIGHT pattern
build:
  steps:
    - docker build -t myapp:${VERSION} .
    - docker push myapp:${VERSION}

deploy:
  steps:
    - ssh production-server
    - docker service update --image myapp:${VERSION} mystack_nodeserver

```

--------------------------------

### Install MongoDB from Official Repositories

Source: https://thedecipherist.com/articles/the-mongo-replicaset-guide

Adds the official MongoDB APT repository to the system and installs the mongodb-org package. It automatically detects the Ubuntu version to select the correct repository codename.

```bash
install_mongodb() {
    log_info "Installing MongoDB $MONGODB_VERSION..."

    apt-get update
    apt-get install -y gnupg curl

    curl -fsSL "https://www.mongodb.org/static/pgp/server-${MONGODB_VERSION}.asc" | \
        gpg --dearmor -o /usr/share/keyrings/mongodb-server-${MONGODB_VERSION}.gpg

    . /etc/os-release
    case "$VERSION_ID" in
        "24.04") CODENAME="noble" ;;
        *) CODENAME="jammy" ;;
    esac

    echo "deb [ arch=amd64,arm64 signed-by=/usr/share/keyrings/mongodb-server-${MONGODB_VERSION}.gpg ] https://repo.mongodb.org/apt/ubuntu ${CODENAME}/mongodb-org/${MONGODB_VERSION} multiverse" | \
        tee /etc/apt/sources.list.d/mongodb-org-${MONGODB_VERSION}.list

    apt-get update
    apt-get install -y mongodb-org

    log_success "MongoDB $MONGODB_VERSION installed"
}
```

--------------------------------

### Install AI-Pooler CLI Tool

Source: https://thedecipherist.com/articles/rulecatch

This command installs the AI-Pooler command-line interface tool. It requires an API key for initialization and sets up necessary hooks and configuration files.

```bash
npx @rulecatch/ai-pooler init --api-key=YOUR_KEY
```

--------------------------------

### GET /db/system.profile

Source: https://thedecipherist.com/articles/the-mongo-replicaset-guide

Queries the system.profile collection to identify slow or inefficient database operations.

```APIDOC
## GET /db/system.profile

### Description
Retrieves performance data from the capped system.profile collection.

### Method
GET

### Endpoint
db.system.profile.find(query)

### Parameters
#### Query Parameters
- **ts** (date) - Optional - Filter by timestamp.
- **ns** (string) - Optional - Filter by namespace (database.collection).
- **millis** (integer) - Optional - Filter by execution time.

### Request Example
{
  "millis": { "$gt": 100 }
}

### Response
#### Success Response (200)
- **op** (string) - Operation type
- **ns** (string) - Namespace
- **millis** (integer) - Execution time
- **planSummary** (string) - Execution plan (e.g., COLLSCAN)

#### Response Example
{
  "op": "query",
  "ns": "mydb.users",
  "millis": 2,
  "planSummary": "IXSCAN { email: 1 }"
}
```

--------------------------------

### Scaffold New Projects via CLI

Source: https://thedecipherist.com/articles/claude-code-mastery-project-starter-kit

Command-line interface for initializing new projects based on pre-configured stack profiles. It supports various technology stacks including Go, SvelteKit, and clean infrastructure templates.

```bash
/new-project my-app go             # Go API with standard layout
/new-project my-app clean          # Just the Claude infrastructure
/new-project my-app sveltekit      # SvelteKit full-stack app
```

--------------------------------

### Configure Firewall Rules for MongoDB

Source: https://thedecipherist.com/articles/the-mongo-replicaset-guide

Examples of restricting MongoDB access to specific private network ranges using UFW and iptables.

```bash
# UFW example
sudo ufw default deny incoming
sudo ufw allow from 10.0.0.0/8 to any port 27017
sudo ufw allow from 172.16.0.0/12 to any port 27017
sudo ufw deny 27017
sudo ufw enable

# iptables example
iptables -A INPUT -p tcp --dport 27017 -s 10.0.0.0/8 -j ACCEPT
iptables -A INPUT -p tcp --dport 27017 -j DROP
```

--------------------------------

### Application Logging Best Practices (Node.js)

Source: https://thedecipherist.com/articles/the_docker_developer_workflow_guide_2026

Illustrates recommended practices for logging within a Node.js application. It shows how to correctly log to stdout/stderr using `console.log` and `console.error`, and how to use a structured logging library like Pino. It also contrasts this with the incorrect practice of writing logs to files within the container, which Docker's drivers do not capture.

```javascript
// GOOD - Docker captures this
console.log('Server started on port 3000');
console.error('Database connection failed:', err.message);

// GOOD - structured logging to stdout
const pino = require('pino');
const logger = pino({ level: process.env.LOG_LEVEL || 'info' });
logger.info({ port: 3000 }, 'Server started');
logger.error({ err }, 'Database connection failed');

// BAD - Docker never sees this, lost when container dies
const fs = require('fs');
fs.appendFileSync('/app/logs/app.log', 'Server started\n');
```

--------------------------------

### Install and Run MongoDB Exporter

Source: https://thedecipherist.com/articles/the-mongo-replicaset-guide

Steps to download, extract, and run the MongoDB Exporter for Prometheus, including specifying the MongoDB connection URI.

```bash
# Install mongodb_exporter
wget https://github.com/percona/mongodb_exporter/releases/download/v0.40.0/mongodb_exporter-0.40.0.linux-amd64.tar.gz
tar xvzf mongodb_exporter-0.40.0.linux-amd64.tar.gz

# Run exporter
./mongodb_exporter --mongodb.uri="mongodb://monitor:password@localhost:27017/admin"
```

--------------------------------

### Implementing Semantic Versioning for Docker

Source: https://thedecipherist.com/articles/the_docker_developer_workflow_guide_2026

Shows how to tag Docker images with semantic version numbers and how to automate this process by reading version strings from a file.

```bash
docker build -t myapp:1.4.72 .
docker push myapp:1.4.72
```

```bash
# buildVersion.txt
1.4.72

# Build script
BUILD_VERSION=$(cat ./globals/_versioning/buildVersion.txt)
docker build -t myapp:${BUILD_VERSION} .
docker push myapp:${BUILD_VERSION}
```

--------------------------------

### Prometheus Alerting Rules for MongoDB

Source: https://thedecipherist.com/articles/the-mongo-replicaset-guide

Example Prometheus alerting rules to monitor MongoDB replication lag, high connection usage, and instance availability.

```yaml
# Prometheus alerting rules
groups:
  - name: mongodb
    rules:
      - alert: MongoDBReplicationLag
        expr: mongodb_rs_members_optimeDate{state="SECONDARY"} - mongodb_rs_members_optimeDate{state="PRIMARY"} > 60
        for: 5m
        labels:
          severity: critical
        annotations:
          summary: "MongoDB replication lag > 60 seconds"

      - alert: MongoDBConnectionsHigh
        expr: mongodb_ss_connections{conn_type="current"} / mongodb_ss_connections{conn_type="available"} > 0.8
        for: 5m
        labels:
          severity: warning
        annotations:
          summary: "MongoDB connections > 80% of max"

      - alert: MongoDBDown
        expr: up{job="mongodb"} == 0
        for: 1m
        labels:
          severity: critical
        annotations:
          summary: "MongoDB instance is down"
```

--------------------------------

### MongoDB Networking in Docker (Docker Compose)

Source: https://thedecipherist.com/articles/the-mongo-replicaset-guide

Illustrates different Docker networking strategies for MongoDB. The 'BAD' example uses the default bridge network, which prevents container-to-container resolution. The 'GOOD' examples show custom bridge and overlay networks, essential for replica set communication and client access.

```yaml
# ❌ BAD: Default bridge network (containers can't resolve each other)
networks:
  - default
```

```yaml
# ✅ GOOD: Custom bridge network (development)
networks:
  mongo-cluster:
    driver: bridge
```

```yaml
# ✅ GOOD: Overlay network (Swarm production)
networks:
  mongo-net:
    driver: overlay
    attachable: true
```

--------------------------------

### Configure MongoDB Profiling Levels

Source: https://thedecipherist.com/articles/the-mongo-replicaset-guide

Demonstrates how to safely enable and disable database profiling. It includes examples of using thresholds and sampling to minimize production overhead.

```javascript
// ❌ DANGEROUS: Low threshold, no sampling
db.setProfilingLevel(1, { slowms: 10 });

// ❌ NEVER IN PRODUCTION
db.setProfilingLevel(2);

// ✅ SAFER: High threshold
db.setProfilingLevel(1, { slowms: 100 });

// ✅ SAFEST: High threshold + sampling (MongoDB 4.0+)
db.setProfilingLevel(1, { slowms: 50, sampleRate: 0.1 });

// ✅ BEST: Profile briefly, then disable
db.setProfilingLevel(1, { slowms: 100 });
// ... collect data for 5-10 minutes ...
db.setProfilingLevel(0);
```

--------------------------------

### Local Development Workflow Comparison

Source: https://thedecipherist.com/articles/the_docker_developer_workflow_guide_2026

Comparison of local development commands between Docker Swarm and Kubernetes environments.

```bash
# Your entire local dev workflow
docker compose up -d
# Edit code, see changes via bind mounts
# Done
```

--------------------------------

### Clone and Initialize Claude Code Starter Kit

Source: https://thedecipherist.com/articles/best_claude_code_guide_2026

This snippet provides the commands to clone the official Claude Code mastery project starter kit from GitHub and initialize the environment using the /setup slash command.

```bash
git clone https://github.com/TheDecipherist/claude-code-mastery-project-starter-kit.git
cd claude-code-mastery-project-starter-kit
# Open Claude Code and run /setup
```

--------------------------------

### MongoDB Authentication with Docker Secrets (Docker Compose)

Source: https://thedecipherist.com/articles/the-mongo-replicaset-guide

Demonstrates secure password and keyfile management for MongoDB using Docker secrets. The 'BAD' example stores the password in plain text within the environment variables. The 'GOOD' example utilizes Docker secrets for sensitive information, enhancing security in Swarm environments.

```yaml
# ❌ BAD: Password in plain text in compose file
environment:
  - MONGO_INITDB_ROOT_PASSWORD=mysecretpassword
```

```yaml
# ✅ GOOD: Use Docker secrets (Swarm)
secrets:
  - mongodb-keyfile
  - mongodb-root-password
```

--------------------------------

### Configure Hostnames on Ubuntu Servers

Source: https://thedecipherist.com/articles/the-mongo-replicaset-guide

Sets the hostname for each MongoDB node using the `hostnamectl` command. This is crucial for replica set member identification starting from MongoDB 5.0.

```bash
# On mongodb1
sudo hostnamectl set-hostname mongodb1.yourdomain.com

# On mongodb2  
sudo hostnamectl set-hostname mongodb2.yourdomain.com

# On mongodb3
sudo hostnamectl set-hostname mongodb3.yourdomain.com
```

--------------------------------

### Image-Based Workflow Visualization

Source: https://thedecipherist.com/articles/the_docker_developer_workflow_guide_2026

This diagram illustrates the recommended image-based workflow. It shows the flow of code from a developer's machine, through building and testing a Docker image, to pushing it to a registry, and finally deploying it to a production environment. The key takeaway is that the production environment only interacts with immutable Docker images.

```text
Developer machine                     Registry                    Production
      |                                  |                            |
      |- Write code                      |                            |
      |- docker compose up (test locally)|                            |
      |- docker compose build            |                            |
      |- Run tests against the image     |                            |
      |- docker compose push ----------> | Image stored               |
      |                                  | (myapp:1.4.72)             |
      |                                  |                            |
      |- docker stack deploy ---------------------------------------> |
      |  (or CI/CD triggers deploy)      |                            |
      |                                  | <---- docker pull ---------|
      |                                  |       (pulls myapp:1.4.72) |
      |                                  |                            |- Container starts
      |                                  |                            |- Health check passes
      |                                  |                            |- Old container stops
      |                                  |                            |
      |                                  |                            |  (It's running the
      |                                  |                            |   exact same image
      |                                  |                            |   you tested locally)

```

--------------------------------

### Basic Docker Container and Image Management Commands

Source: https://thedecipherist.com/articles/the_docker_developer_workflow_guide_2026

A quick reference for essential Docker commands related to container lifecycle management, logging, inspection, and execution. Includes commands for listing, stopping, removing, and interacting with containers and images.

```bash
docker ps
docker ps -a
docker logs <container>
docker logs --tail 100 -f <container>
docker logs -t <container>
docker inspect <container>
docker exec -it <container> /bin/sh
docker run --rm -it --entrypoint /bin/sh <image>
docker stop <container>
docker kill <container>
docker rm <container>
docker rm -f <container>
```

--------------------------------

### MongoDB Configuration Variables

Source: https://thedecipherist.com/articles/the-mongo-replicaset-guide

Configuration settings for the automated installation script, including node identification, replica set naming, and resource allocation for the WiredTiger storage engine.

```bash
# Node Configuration
NODE_HOSTNAME="mongodb1.yourdomain.com"
NODE_IP="10.10.1.122"
REPLICA_SET_NAME="rs0"

# Other Replica Set Members
OTHER_NODES=(
    "10.10.1.175 mongodb2.yourdomain.com mongodb2"
    "10.10.1.136 mongodb3.yourdomain.com mongodb3"
)

# Data Drive
DATA_DRIVE="/dev/nvme1n1"
DATA_PATH="/data/mongodb"

# MongoDB Settings
WIREDTIGER_CACHE_GB="2"
INIT_REPLICA_SET="false"
ADMIN_PASSWORD=""
```

--------------------------------

### Install Node.js, Yarn, and Python Tools in Dockerfile

Source: https://thedecipherist.com/articles/docker-swarm-guide

This Dockerfile instruction installs Node.js (version 20.x), essential Python tools like pip and pipenv, and Chromium. It configures the NodeSource repository and cleans up apt cache afterwards to minimize image size.

```dockerfile
# Install Node.js, Yarn, and Python tools
RUN \
  echo "deb [signed-by=/etc/apt/keyrings/nodesource.gpg] https://deb.nodesource.com/node_20.x nodistro main" > /etc/apt/sources.list.d/nodesource.list && \
  wget -qO- https://deb.nodesource.com/gpgkey/nodesource-repo.gpg.key | gpg --dearmor -o /etc/apt/keyrings/nodesource.gpg && \
  apt-get update && \
  apt-get install -y --no-install-recommends \
  chromium \
  nodejs && \
  pip install -U pip && pip install pipenv && \
  apt-get clean && \
  rm -rf /var/lib/apt/lists/*
```