net/tex/main.tex

\documentclass{article}
\usepackage{listings}
\usepackage{xcolor}

\title{Docker Image Deployment and Kubernetes Configuration}
\author{Your Name}
\date{\today}

\lstset{
  basicstyle=\ttfamily,
  keywordstyle=\color{blue},
  commentstyle=\color{gray},
  stringstyle=\color{orange},
  breaklines=true,
  frame=single,
  language=bash
}

\begin{document}

\maketitle

\section*{Instructions}

\textbf{Prerequisites:} Docker, Kubernetes, BusyBox, and OpenSSL installed, along with a working directory containing a Dockerfile.

\begin{enumerate}
    \item \textbf{Run a Local Docker Registry (without authentication):}
    \begin{lstlisting}
docker run -d -p 5000:5000 --name registry registry:2
    \end{lstlisting}
    This command starts a registry container on \texttt{localhost:5000}.

    \item \textbf{Optional: Enable Authentication for the Local Registry}

    If you want to secure your local registry with a username and password, follow these steps:
    
    \begin{enumerate}
        \item \textbf{Create a User and Password Hash with BusyBox:}
        Generate a hashed password for `passpass` and store it in the `htpasswd` file:
        \begin{lstlisting}
mkdir -p /home/user/auth
echo "user:$(busybox mkpasswd -m sha256 -S $(openssl rand -hex 6) passpass)" > /home/user/auth/htpasswd
        \end{lstlisting}
        This command generates a hashed password `passpass` for the username `user`.

        \item \textbf{Run the Registry with Authentication:}
        Restart the registry container to require authentication.
        \begin{lstlisting}
docker stop registry
docker rm registry
docker run -d -p 5000:5000 --name registry \
  -v /home/user/auth:/auth \
  -e "REGISTRY_AUTH=htpasswd" \
  -e "REGISTRY_AUTH_HTPASSWD_REALM=Registry Realm" \
  -e "REGISTRY_AUTH_HTPASSWD_PATH=/auth/htpasswd" \
  registry:2
        \end{lstlisting}
    \end{enumerate}
    
    \item \textbf{Build and Push Docker Image to Local Registry:}
    \begin{lstlisting}
docker build -f Dockerfile -t localhost:5000/my-app:latest ..
docker push localhost:5000/my-app:latest
    \end{lstlisting}

    \item \textbf{Configure Kubernetes to Use the Local Registry (if using authentication):}
    Create a Kubernetes secret with credentials to access the registry:
    \begin{lstlisting}
kubectl create secret docker-registry regcred \
  --docker-server=localhost:5000 \
  --docker-username=user \
  --docker-password=passpass \
  --docker-email=user@example.com
    \end{lstlisting}
    This secret can be referenced by Kubernetes to pull the image from the secured local registry.

    \item \textbf{Deploy a Pod Using the Image from the Local Registry:}
    \begin{lstlisting}
kubectl run my-app --image=localhost:5000/my-app:latest --image-pull-policy=IfNotPresent
    \end{lstlisting}
\end{enumerate}

\section{Adding a Docker Image to Minikube and Exposing It}

\subsection{Load Docker Image into Minikube}

1. \textbf{Build and Load Docker Image Directly into Minikube:}
   If the image is built locally, you can load it directly into Minikube:

   \begin{lstlisting}
   minikube image load my-app:latest
   \end{lstlisting}

   Alternatively, if you are using a local registry, ensure Minikube can access it by setting the registry address in the image tag.

\subsection{Create and Run a Pod with the Loaded Image}

1. \textbf{Create a Deployment in Minikube:}
   Create a Kubernetes Deployment to manage the pod using the loaded image:

   \begin{lstlisting}
   kubectl create deployment my-app --image=my-app:latest
   \end{lstlisting}

2. \textbf{Expose the Deployment as a Service:}
   Expose the Deployment to make the application accessible on an external port:

   \begin{lstlisting}
   kubectl expose deployment my-app --type=NodePort --port=80 --target-port=8080
   \end{lstlisting}

   In this example, Kubernetes maps port 80 of the service to port 8080 of the container. Modify `target-port` if your application uses a different port.

\subsection{Access the Application Externally}

1. \textbf{Retrieve the Minikube Service URL:}
   Minikube provides a command to get the external URL for accessing services. Run the following command to get the URL:

   \begin{lstlisting}
   minikube service my-app --url
   \end{lstlisting}

   This command will output a URL that you can use to access the service from outside of Minikube.

\end{document}