install_kubernetes.sh

#!/bin/bash

# This script installs or updates various development tools (Terraform, Ansible, Kubernetes, kubectl, Helm, etc.)
# for setting up a Kubernetes cluster and other necessary tools on WSL (Windows Subsystem for Linux).
# Save this script in a file (e.g., install_dependencies.sh) and run it in your WSL environment.
# To update non-APT dependencies (e.g., kustomize, ArgoCD, yq), pass the --update flag when executing the script.
#
# Example usage:
#   ./install_dependencies.sh            # Installs everything
#   ./install_dependencies.sh --update   # Updates only non-APT dependencies like kustomize, yq, ArgoCD, etc.
# or you execute it via:
# curl -sL https://gist.githubusercontent.com/JoelGotsch/eb8a888a4f48d5758ce37a57e1bfe15c/raw/install_kubernetes.sh | sudo bash
# and for updating:
# curl -sL https://gist.githubusercontent.com/JoelGotsch/eb8a888a4f48d5758ce37a57e1bfe15c/raw/install_kubernetes.sh | sudo bash -s -- --update


# Global variables
UPDATE=false  # Flag to determine if we should update non-APT dependencies

# Check if user requested update mode
if [[ "$1" == "--update" ]]; then
    UPDATE=true
fi

# Function to check if a command exists
command_exists() {
    command -v "$@" >/dev/null 2>&1
}

# Function to install or update Kustomize
install_or_update_kustomize() {
    if [[ "$UPDATE" == true ]] || ! command_exists kustomize; then
        echo "Installing or updating Kustomize..."
        curl -s "https://raw.githubusercontent.com/kubernetes-sigs/kustomize/master/hack/install_kustomize.sh" | bash
        sudo mv kustomize /usr/local/bin/
        sudo chmod +x /usr/local/bin/kustomize
        echo "Kustomize installed or updated."
    else
        echo "Kustomize is already installed."
    fi
}

# Function to install or update ArgoCD CLI
install_or_update_argocd() {
    if [[ "$UPDATE" == true ]] || ! command_exists argocd; then
        echo "Installing or updating Argo CD CLI..."
        VERSION=$(curl -L -s https://raw.githubusercontent.com/argoproj/argo-cd/stable/VERSION)
        curl -sSL -o argocd-linux-amd64 https://github.com/argoproj/argo-cd/releases/download/v$VERSION/argocd-linux-amd64
        sudo install -m 555 argocd-linux-amd64 /usr/local/bin/argocd
        rm argocd-linux-amd64
        echo "Argo CD CLI installed or updated to version $VERSION."
    else
        echo "Argo CD CLI is already installed."
    fi
}

# Function to install or update yq
install_or_update_yq() {
    if [[ "$UPDATE" == true ]] || ! command_exists yq; then
        echo "Attempting to install yq via snap..."
        sudo snap install yq || {
            echo "Snap installation failed."
            echo "To install yq via snap in WSL2, run the following command to enable snap:"
            echo "sudo bash -c \"\$(wget -O- https://gist.githubusercontent.com/JoelGotsch/eb8a888a4f48d5758ce37a57e1bfe15c/raw/setup-wsl2-snap-support.sh)\""
        }
    else
        echo "yq is already installed."
    fi
}

# Update and upgrade the system
echo "Updating and upgrading the system packages..."
sudo apt update && sudo apt upgrade -y
echo "System packages updated."

# Install basic dependencies
echo "Installing basic dependencies: curl, wget, git, unzip, jq, etc..."
sudo apt install -y \
    curl \
    wget \
    git \
    unzip \
    software-properties-common \
    apt-transport-https \
    ca-certificates \
    gnupg-agent \
    build-essential \
    python3 \
    python3-pip \
    python3-venv \
    jq
echo "Basic dependencies installed."

# Install Docker (Client only, as Docker Desktop handles the daemon)
if ! command_exists docker; then
    echo "Installing Docker..."
    sudo apt install -y docker.io
    echo "Docker installed."
else
    echo "Docker is already installed."
fi

# Check if the user is already part of the docker group
if groups $USER | grep -q "\bdocker\b"; then
    echo "User is already in the docker group."
else
    echo "Adding user to the docker group..."
    sudo usermod -aG docker $USER
    echo "User added to the docker group. You will need to log out and back in to use Docker without sudo."
    LOGOUT_NEEDED=true
fi

# Install Terraform via APT
if ! command_exists terraform; then
    echo "Installing Terraform via APT..."
    if [ ! -f /usr/share/keyrings/hashicorp-archive-keyring.gpg ]; then
        wget -O- https://apt.releases.hashicorp.com/gpg | sudo gpg --dearmor -o /usr/share/keyrings/hashicorp-archive-keyring.gpg
    fi
    if [ ! -f /etc/apt/sources.list.d/hashicorp.list ]; then
        echo "deb [signed-by=/usr/share/keyrings/hashicorp-archive-keyring.gpg] https://apt.releases.hashicorp.com $(lsb_release -cs) main" | sudo tee /etc/apt/sources.list.d/hashicorp.list
    fi
    sudo apt update && sudo apt install -y terraform
    echo "Terraform installed."
else
    echo "Terraform is already installed."
fi

# Install Ansible via APT
if ! command_exists ansible; then
    echo "Installing Ansible via APT..."
    sudo apt install -y ansible
    echo "Ansible installed."
else
    echo "Ansible is already installed."
fi

# Install Helm via APT
if ! command_exists helm; then
    echo "Installing Helm via APT..."
    if [ ! -f /usr/share/keyrings/helm.gpg ]; then
        curl https://baltocdn.com/helm/signing.asc | gpg --dearmor | sudo tee /usr/share/keyrings/helm.gpg > /dev/null
    fi
    if [ ! -f /etc/apt/sources.list.d/helm-stable-debian.list ]; then
        echo "deb [arch=$(dpkg --print-architecture) signed-by=/usr/share/keyrings/helm.gpg] https://baltocdn.com/helm/stable/debian/ all main" | sudo tee /etc/apt/sources.list.d/helm-stable-debian.list
    fi
    sudo apt-get update
    sudo apt-get install -y helm
    echo "Helm installed."
else
    echo "Helm is already installed."
fi

# Install or update Kustomize
install_or_update_kustomize

# Install or update ArgoCD CLI
install_or_update_argocd

# Install or update yq
install_or_update_yq

# Install Kubernetes components via APT (kubeadm, kubelet, kubectl)
if ! command_exists kubectl; then
    echo "Installing Kubernetes components (kubectl, kubeadm, kubelet) via APT..."

    # Check if the keyring exists
    if [ ! -f /etc/apt/keyrings/kubernetes-apt-keyring.gpg ]; then
        sudo mkdir -p /etc/apt/keyrings
        curl -fsSL https://pkgs.k8s.io/core:/stable:/v1.28/deb/Release.key | sudo gpg --dearmor -o /etc/apt/keyrings/kubernetes-apt-keyring.gpg
    else
        echo "Kubernetes keyring already exists."
    fi

    # Check if the repository is added
    if [ ! -f /etc/apt/sources.list.d/kubernetes.list ]; then
        echo "deb [signed-by=/etc/apt/keyrings/kubernetes-apt-keyring.gpg] https://pkgs.k8s.io/core:/stable:/v1.28/deb/ /" | sudo tee /etc/apt/sources.list.d/kubernetes.list
    else
        echo "Kubernetes repository already exists."
    fi

    sudo apt-get update
    sudo apt-get install -y kubelet kubeadm kubectl
    sudo apt-mark hold kubelet kubeadm kubectl
    echo "Kubernetes components installed."
else
    echo "Kubernetes components are already installed."
fi

# Final message to user
echo "All dependencies have been installed successfully."

# Inform the user if they need to log out and back in for Docker group changes to take effect
if [ "$LOGOUT_NEEDED" = true ]; then
    echo "You will need to log out and back in to use Docker without sudo."
fi