loc_az_hci/infrastructure/kubernetes/k3s-install.sh

#!/bin/bash
# K3s Installation Script for Proxmox VMs
# Installs lightweight Kubernetes (K3s) for Azure Arc integration

set -e

# Colors for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
NC='\033[0m'

# K3s configuration
K3S_VERSION="${K3S_VERSION:-latest}"
INSTALL_MODE="${INSTALL_MODE:-local}"  # 'local' or 'remote'
REMOTE_IP="${REMOTE_IP:-}"
REMOTE_USER="${REMOTE_USER:-root}"
SSH_KEY="${SSH_KEY:-}"

log_info() {
    echo -e "${GREEN}[INFO]${NC} $1"
}

log_warn() {
    echo -e "${YELLOW}[WARN]${NC} $1"
}

log_error() {
    echo -e "${RED}[ERROR]${NC} $1"
}

check_root() {
    if [ "$INSTALL_MODE" = "local" ] && [ "$EUID" -ne 0 ]; then 
        log_error "Please run as root for local installation"
        exit 1
    fi
}

install_k3s_local() {
    log_info "Installing K3s locally..."
    
    # Check if already installed
    if command -v k3s &> /dev/null; then
        log_warn "K3s already installed"
        k3s --version
        return
    fi
    
    # Install K3s
    log_info "Downloading and installing K3s..."
    curl -sfL https://get.k3s.io | INSTALL_K3S_VERSION="$K3S_VERSION" sh -
    
    # Verify installation
    if command -v k3s &> /dev/null; then
        log_info "K3s installed successfully"
        k3s --version
        
        # Start and enable service
        systemctl enable k3s
        systemctl start k3s
        
        # Wait for service to be ready
        log_info "Waiting for K3s to be ready..."
        sleep 10
        
        # Verify service status
        if systemctl is-active --quiet k3s; then
            log_info "K3s service is running"
        else
            log_error "K3s service failed to start"
            systemctl status k3s
            exit 1
        fi
    else
        log_error "K3s installation failed"
        exit 1
    fi
}

install_k3s_remote() {
    log_info "Installing K3s on remote host: $REMOTE_IP"
    
    if [ -z "$REMOTE_IP" ]; then
        log_error "REMOTE_IP must be set for remote installation"
        exit 1
    fi
    
    # Check connectivity
    if ! ping -c 1 -W 2 "$REMOTE_IP" &> /dev/null; then
        log_error "Cannot reach remote host: $REMOTE_IP"
        exit 1
    fi
    
    # Create installation script
    cat > /tmp/install_k3s_remote.sh <<EOF
#!/bin/bash
set -e

# Check if already installed
if command -v k3s &> /dev/null; then
    echo "K3s already installed"
    k3s --version
    exit 0
fi

# Install K3s
curl -sfL https://get.k3s.io | INSTALL_K3S_VERSION="$K3S_VERSION" sh -

# Verify installation
if command -v k3s &> /dev/null; then
    echo "K3s installed successfully"
    k3s --version
    
    # Start and enable service
    sudo systemctl enable k3s
    sudo systemctl start k3s
    
    # Wait for service to be ready
    sleep 10
    
    # Verify service status
    if sudo systemctl is-active --quiet k3s; then
        echo "K3s service is running"
        sudo systemctl status k3s --no-pager
    else
        echo "K3s service failed to start"
        sudo systemctl status k3s --no-pager
        exit 1
    fi
else
    echo "K3s installation failed"
    exit 1
fi
EOF

    # Copy and execute on remote host
    if [ -n "$SSH_KEY" ]; then
        scp -i "$SSH_KEY" -o StrictHostKeyChecking=no /tmp/install_k3s_remote.sh "$REMOTE_USER@$REMOTE_IP:/tmp/"
        ssh -i "$SSH_KEY" -o StrictHostKeyChecking=no "$REMOTE_USER@$REMOTE_IP" "chmod +x /tmp/install_k3s_remote.sh && /tmp/install_k3s_remote.sh"
    else
        scp -o StrictHostKeyChecking=no /tmp/install_k3s_remote.sh "$REMOTE_USER@$REMOTE_IP:/tmp/"
        ssh -o StrictHostKeyChecking=no "$REMOTE_USER@$REMOTE_IP" "chmod +x /tmp/install_k3s_remote.sh && /tmp/install_k3s_remote.sh"
    fi
    
    log_info "K3s installed on remote host"
}

configure_kubectl() {
    log_info "Configuring kubectl..."
    
    if [ "$INSTALL_MODE" = "local" ]; then
        # Copy kubeconfig for local access
        mkdir -p ~/.kube
        cp /etc/rancher/k3s/k3s.yaml ~/.kube/config
        sed -i 's/127.0.0.1/localhost/g' ~/.kube/config
        
        export KUBECONFIG=~/.kube/config
    else
        # Get kubeconfig from remote
        mkdir -p ~/.kube
        
        if [ -n "$SSH_KEY" ]; then
            ssh -i "$SSH_KEY" -o StrictHostKeyChecking=no "$REMOTE_USER@$REMOTE_IP" \
                "sudo cat /etc/rancher/k3s/k3s.yaml" > ~/.kube/config
        else
            ssh -o StrictHostKeyChecking=no "$REMOTE_USER@$REMOTE_IP" \
                "sudo cat /etc/rancher/k3s/k3s.yaml" > ~/.kube/config
        fi
        
        # Update server URL
        sed -i "s/127.0.0.1/$REMOTE_IP/g" ~/.kube/config
        export KUBECONFIG=~/.kube/config
    fi
    
    # Verify kubectl access
    if command -v kubectl &> /dev/null; then
        log_info "Testing kubectl connection..."
        kubectl cluster-info
        kubectl get nodes
    else
        log_warn "kubectl not found. Install it to manage the cluster:"
        log_info "  curl -LO https://dl.k8s.io/release/\$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl"
    fi
}

verify_installation() {
    log_info "Verifying K3s installation..."
    
    if [ "$INSTALL_MODE" = "local" ]; then
        if systemctl is-active --quiet k3s; then
            log_info "K3s service is running"
            k3s kubectl get nodes
            k3s kubectl get pods --all-namespaces
        else
            log_error "K3s service is not running"
            exit 1
        fi
    else
        if [ -n "$SSH_KEY" ]; then
            SSH_CMD="ssh -i $SSH_KEY -o StrictHostKeyChecking=no $REMOTE_USER@$REMOTE_IP"
        else
            SSH_CMD="ssh -o StrictHostKeyChecking=no $REMOTE_USER@$REMOTE_IP"
        fi
        
        if $SSH_CMD "sudo systemctl is-active --quiet k3s"; then
            log_info "K3s service is running on remote host"
            kubectl get nodes
            kubectl get pods --all-namespaces
        else
            log_error "K3s service is not running on remote host"
            exit 1
        fi
    fi
}

main() {
    log_info "Starting K3s installation (mode: $INSTALL_MODE)..."
    check_root
    
    case "$INSTALL_MODE" in
        local)
            install_k3s_local
            configure_kubectl
            ;;
        remote)
            install_k3s_remote
            configure_kubectl
            ;;
        *)
            log_error "INSTALL_MODE must be 'local' or 'remote'"
            exit 1
            ;;
    esac
    
    verify_installation
    log_info "K3s installation completed successfully!"
    log_info "Kubeconfig location: ~/.kube/config"
}

main "$@"