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\begin{titlepage}
\centering
\vspace*{3cm}
{\Huge\bfseries\color{azureblue} Task Manager}\\[0.5cm]
{\LARGE Cloud Deployment Documentation}\\[2cm]

\begin{tabular}{rl}
    \textbf{Course:}     & Cloud Technologies / Web Application Deployment \\
    \textbf{Student:}    & Gopi Suvanam \\
    \textbf{Login:}      & gs699he \\
    \textbf{Date:}       & \today \\
    \textbf{Cloud:}      & Microsoft Azure (Azure for Students) \\
    \textbf{Repository:} & \url{https://git.kemt.fei.tuke.sk/gs699he/zkt25} \\
\end{tabular}

\vspace{3cm}
\includegraphics[width=0.65\textwidth]{architecture.png}
\vfill
{\small Technical University of Ko\v{s}ice -- KEMT FEI}
\end{titlepage}

\tableofcontents
\newpage

% =============================================================
\section{Application Overview}
% =============================================================

The \textbf{Task Manager} is a full-stack web application for creating, reading, updating, and deleting (CRUD) tasks. It is deployed to \textbf{Microsoft Azure} using Docker Compose on an Azure Virtual Machine.

\subsection{Key Features}
\begin{itemize}[nosep]
    \item RESTful API with full CRUD operations
    \item Apple-inspired premium UI with glassmorphism
    \item Redis caching (30s TTL) for API optimization
    \item PostgreSQL database with persistent volume and backup scripts
    \item Automatic HTTPS via Caddy + Let's Encrypt
    \item Fully automated deployment via shell scripts
    \item Auto-restart on container failure
\end{itemize}

% =============================================================
\section{Architecture}
% =============================================================

The application uses a \textbf{5-container microservices architecture} on an Azure VM, orchestrated by Docker Compose.

\begin{figure}[H]
    \centering
    \includegraphics[width=0.72\textwidth]{architecture.png}
    \caption{Architecture -- 5 Docker containers on Azure VM}
    \label{fig:architecture}
\end{figure}

\subsection{Container Descriptions}

\begin{longtable}{@{}p{2.8cm}p{3cm}p{7.7cm}@{}}
\toprule
\textbf{Container} & \textbf{Image} & \textbf{Purpose} \\
\midrule
\endhead
Caddy & caddy:2-alpine & Reverse proxy with automatic HTTPS/TLS via Let's Encrypt. Ports 80, 443. \\[6pt]
Frontend & nginx:alpine & Serves static HTML/CSS/JS, proxies \texttt{/api/} to backend. \\[6pt]
API & node:20-alpine & Express.js REST API with CRUD endpoints. \\[6pt]
PostgreSQL & postgres:16-alpine & Persistent database with Docker named volume. \\[6pt]
Redis & redis:7-alpine & In-memory cache with AOF persistence. \\
\bottomrule
\end{longtable}

\subsection{Network Isolation}

\begin{itemize}[nosep]
    \item \texttt{frontend-net} -- Caddy, Frontend, API
    \item \texttt{backend-net} -- API, PostgreSQL, Redis
\end{itemize}

Database and cache are \textbf{not accessible} from the internet. Only the API bridges both networks.

% =============================================================
\section{Azure Services Used}
% =============================================================

\begin{longtable}{@{}p{4.5cm}p{9cm}@{}}
\toprule
\textbf{Service} & \textbf{Usage} \\
\midrule
\endhead
Azure VM (Standard\_B1s) & Ubuntu 24.04, 1 vCPU, 1 GB RAM. Runs Docker. \\[6pt]
Public IP + DNS & \texttt{*.westeurope.cloudapp.azure.com} for HTTPS. \\[6pt]
Azure for Students & \$100 free credit, no credit card required. \\[6pt]
Let's Encrypt & Free TLS certificates via Caddy (auto-renewal). \\[6pt]
cloud-init & Installs Docker on first VM boot automatically. \\
\bottomrule
\end{longtable}

% =============================================================
\section{File Descriptions}
% =============================================================

\begin{longtable}{@{}p{4.5cm}p{9cm}@{}}
\toprule
\textbf{File} & \textbf{Description} \\
\midrule
\endhead
\texttt{docker-compose.yaml} & 5 services, 2 networks, persistent volumes. \\[4pt]
\texttt{prepare-app.sh} & Creates Azure VM, installs Docker, deploys app. \\[4pt]
\texttt{remove-app.sh} & Deletes Azure resource group (all resources). \\[4pt]
\texttt{backup-db.sh} & SSH + pg\_dump for database backups. \\[4pt]
\texttt{view-logs.sh} & Retrieves container logs via SSH. \\[4pt]
\texttt{cloud-init.yaml} & Auto-installs Docker on VM first boot. \\[4pt]
\texttt{env.example} & Template for secrets (copied to .env). \\[4pt]
\texttt{caddy/Caddyfile} & HTTPS reverse proxy configuration. \\[4pt]
\texttt{frontend/} & Nginx Dockerfile, config, static files. \\[4pt]
\texttt{api/} & Node.js Dockerfile, Express server, DB pool. \\[4pt]
\texttt{db/init.sql} & Database schema and sample data. \\[4pt]
\texttt{docs/} & This documentation + architecture diagram. \\
\bottomrule
\end{longtable}

% =============================================================
\section{Configuration}
% =============================================================

All settings via environment variables in \texttt{.env} (gitignored).

\begin{longtable}{@{}p{4.5cm}p{4.5cm}p{4.5cm}@{}}
\toprule
\textbf{Variable} & \textbf{Description} & \textbf{Default} \\
\midrule
\endhead
\texttt{POSTGRES\_PASSWORD} & Database password & \textit{(required)} \\
\texttt{AZURE\_RESOURCE\_GROUP} & Resource group name & taskmanager-rg \\
\texttt{AZURE\_LOCATION} & Azure region & westeurope \\
\texttt{AZURE\_VM\_SIZE} & VM size & Standard\_B1s \\
\texttt{AZURE\_DNS\_LABEL} & DNS subdomain & taskmanager-gs699he \\
\bottomrule
\end{longtable}

\subsection{Security}
\begin{itemize}[nosep]
    \item \texttt{.env} in \texttt{.gitignore} -- secrets never in Git
    \item Databases on isolated Docker network
    \item HTTPS enforced by Caddy (HTTP $\rightarrow$ HTTPS redirect)
    \item Security headers in Nginx
    \item SSH key authentication (no password login)
\end{itemize}

% =============================================================
\section{Deployment Instructions}
% =============================================================

\subsection{Prerequisites}
\begin{enumerate}[nosep]
    \item Azure CLI: \texttt{curl -sL https://aka.ms/InstallAzureCLIDeb | sudo bash}
    \item Azure for Students subscription activated
    \item \texttt{az login} completed
\end{enumerate}

\subsection{Deploy}
\begin{lstlisting}[language=bash]
# Clone and configure
git clone git@git.kemt.fei.tuke.sk:gs699he/zkt25.git
cd zkt25/sk1
cp env.example .env
nano .env  # Set POSTGRES_PASSWORD

# Deploy to Azure
./prepare-app.sh
# Creates: Resource Group -> VM -> Docker -> Containers

# Access:
# https://taskmanager-gs699he.westeurope.cloudapp.azure.com
\end{lstlisting}

\subsection{Remove (after exam)}
\begin{lstlisting}[language=bash]
./remove-app.sh
# Deletes entire resource group (VM, IP, disk, NSG)
\end{lstlisting}

% =============================================================
\section{Data Persistence and Backups}
% =============================================================

\subsection{Volumes}
\begin{itemize}[nosep]
    \item \texttt{taskapp-pgdata} -- PostgreSQL data
    \item \texttt{taskapp-redisdata} -- Redis AOF
    \item \texttt{taskapp-caddy-data} -- TLS certificates
\end{itemize}

\subsection{Backup}
\begin{lstlisting}[language=bash]
./backup-db.sh
# Output: backups/taskmanager_backup_20260519_020000.sql
\end{lstlisting}

\subsection{Auto-Restart}
All containers: \texttt{restart: always}. Docker starts on boot via systemd.

% =============================================================
\section{Access Logs}
% =============================================================

\begin{lstlisting}[language=bash]
./view-logs.sh              # All logs
./view-logs.sh --caddy      # HTTPS proxy logs
./view-logs.sh --api -f     # Follow API logs real-time
\end{lstlisting}

Log sources:
\begin{itemize}[nosep]
    \item \textbf{Caddy}: JSON -- client IP, status, TLS version
    \item \textbf{API}: \texttt{METHOD /path STATUS duration}
    \item \textbf{Nginx}: Combined log format
\end{itemize}

% =============================================================
\section{Cost Analysis}
% =============================================================

\subsection{Azure for Students -- Monthly Costs}

\begin{longtable}{@{}p{5cm}p{5cm}r@{}}
\toprule
\textbf{Resource} & \textbf{Configuration} & \textbf{Monthly} \\
\midrule
\endhead
Azure VM & Standard\_B1s (1 vCPU, 1 GB) & \$7.59 \\
Public IP & Static IPv4 & \$3.00 \\
OS Disk & 30 GB Premium SSD & \$1.20 \\
TLS Certificate & Let's Encrypt (free) & \$0.00 \\
\midrule
\textbf{Total} & & \textbf{\$11.79} \\
\textbf{Annual} & & \textbf{\$141.48} \\
\bottomrule
\end{longtable}

Azure for Students provides \$100 free credit -- enough for approximately 8 months of operation.

\subsection{Comparison}
\begin{longtable}{@{}p{4cm}p{5cm}r@{}}
\toprule
\textbf{Provider} & \textbf{Plan} & \textbf{Monthly} \\
\midrule
\endhead
Azure (Students) & B1s + \$100 credit & \$11.79 \\
AWS & t3.micro (free 12mo) & \$8.50 \\
DigitalOcean & Basic Droplet 2 GB & \$12.00 \\
Hostinger & KVM 1 (4 GB) & \$5.99 \\
\bottomrule
\end{longtable}

% =============================================================
\section{AI Usage Declaration}
% =============================================================

\begin{itemize}[nosep]
    \item \textbf{Google Antigravity (Gemini)}: Generated scripts, Docker Compose, Nginx/Caddy config, and this documentation.
    \item \textbf{Architecture diagram}: AI-generated from technical specification.
\end{itemize}

All content reviewed, tested, and adapted. Student understands all components.

\end{document}