Way to run kube api server or generic controlplane as standalone go process for testing

controlplanes

#!/usr/bin/env bash

set -euo pipefail

# Base directory for all control plane resources
BASE_DIR="./.controlplanes"

# Subdirectories for certificates, logs, and configs
CERT_DIR="$BASE_DIR/certs"
LOG_DIR="$BASE_DIR/logs"
CONFIG_DIR="$BASE_DIR/configs"

# File paths
PRIVATE_KEY="$CERT_DIR/sa.pem"
PUBLIC_CERT="$CERT_DIR/sa.crt"
LOG_FILE="$LOG_DIR/etcd.log"
TOKEN_FILE="$CONFIG_DIR/tokens.csv"
CONFIG_FILE="$CONFIG_DIR/kubeconfig"

# Hardcoded token data
TOKEN="abc123def4567890"
USERNAME="example-user"
USER_UID="1001"
GROUPS="system-masters"

# API server and cluster configuration
API_SERVER_URL="https://127.0.0.1:6443"
CLUSTER_NAME="kubernetes"
USER_NAME="example-user"

# Define the etcd version to install
ETCD_VER="v3.5.6"
DOWNLOAD_URL="https://github.com/etcd-io/etcd/releases/download/$ETCD_VER/etcd-$ETCD_VER-linux-amd64.tar.gz"

echo "Preparing control plane..."

# Create necessary directories
mkdir -p $CERT_DIR $LOG_DIR $CONFIG_DIR

# Check and generate certificates if they do not exist
if [[ ! -f "$PRIVATE_KEY" || ! -f "$PUBLIC_CERT" ]]; then
    echo "Generating service account private key and certificate..."
    openssl genrsa -out "$PRIVATE_KEY" 2048
    openssl req -new -x509 -key "$PRIVATE_KEY" -out "$PUBLIC_CERT" -days 365 -subj "/CN=service-account-signer"
    echo "Service account private key and certificate generated."
fi

# Install etcd if not already installed
if ! command -v etcd &>/dev/null; then
    echo "Installing etcd..."
    curl -L $DOWNLOAD_URL -o /tmp/etcd-$ETCD_VER-linux-amd64.tar.gz
    tar xzvf /tmp/etcd-$ETCD_VER-linux-amd64.tar.gz -C /tmp
    sudo mv /tmp/etcd-$ETCD_VER-linux-amd64/etcd /usr/local/bin/
    sudo mv /tmp/etcd-$ETCD_VER-linux-amd64/etcdctl /usr/local/bin/
    rm -rf /tmp/etcd-$ETCD_VER-linux-amd64.tar.gz /tmp/etcd-$ETCD_VER-linux-amd64
    etcd --version
    etcdctl version
fi

# Function to start etcd
start_etcd() {
    echo "Starting etcd and logging to $LOG_FILE"
    /usr/local/bin/etcd >>"$LOG_FILE" 2>&1 &
    ETCD_PID=$!
    echo "etcd started with PID $ETCD_PID"
}

# Function to stop etcd
stop_etcd() {
    echo "Stopping etcd..."
    kill $ETCD_PID
    wait $ETCD_PID
    echo "etcd stopped."
}

# Generate tokens.csv if it does not exist
if [ ! -f "$TOKEN_FILE" ]; then
    echo "Generating tokens.csv..."
    echo "$TOKEN,$USERNAME,$USER_UID,$GROUPS" > $TOKEN_FILE
    echo "Generated tokens.csv with contents:"
    cat $TOKEN_FILE
fi

# Configure kubeconfig
if [ ! -f "$CONFIG_FILE" ]; then
    echo "Configuring kubeconfig..."
    kubectl config set-cluster $CLUSTER_NAME --server=$API_SERVER_URL --insecure-skip-tls-verify=true --kubeconfig=$CONFIG_FILE
    kubectl config set-credentials $USER_NAME --token=$TOKEN --kubeconfig=$CONFIG_FILE
    kubectl config set-context default --cluster=$CLUSTER_NAME --user=$USER_NAME --kubeconfig=$CONFIG_FILE
    kubectl config use-context default --kubeconfig=$CONFIG_FILE
    echo "Kubeconfig created and configured:"
    cat $CONFIG_FILE
fi

# Trap SIGINT and SIGTERM to ensure etcd is stopped when the script exits
trap 'stop_etcd; exit 0;' INT TERM

# Start etcd
start_etcd

# Run kube-apiserver
go run ./cmd/kube-apiserver \
   --cert-dir $CERT_DIR \
   --etcd-servers http://127.0.0.1:2379 \
   --service-account-issuer foo \
   --service-account-signing-key-file="$PRIVATE_KEY" \
   --service-account-key-file="$PUBLIC_CERT" \
   --token-auth-file="$TOKEN_FILE" \
   --v=4 \
   --authorization-mode=AlwaysAllow