Add cluster demo script for easy cluster management

This script provides a convenient way to spawn and manage a ToastyFS cluster
for demo and testing purposes. Features include:

- Start a cluster with configurable number of chunk servers
- Automatic building if binary is not present
- Process management with PID tracking
- Status checking for all cluster nodes
- Easy cleanup of all cluster processes
- Separate log files for each server component
- Colorized output for better readability

Usage:
  ./scripts/cluster_demo.sh start [num_servers]  - Start cluster
  ./scripts/cluster_demo.sh stop                 - Stop cluster
  ./scripts/cluster_demo.sh status               - Show status
  ./scripts/cluster_demo.sh clean                - Clean data/logs

.gitignore

@@ -3,6 +3,7 @@
 *.o
 *.a
 chunk_server_data_*
+
 # Coverage reports
 coverage_report/
 *.gcov
@@ -10,3 +11,8 @@ coverage_report/
 *.gcno
 *.wal
 *.tmp
+
+# Cluster demo artifacts
+.cluster_demo.pids
+cluster_logs/
+cluster_data/

scripts/README.md

@@ -1,8 +1,45 @@
-# Branch Coverage Measurement
+# Scripts
 
-This directory contains scripts for measuring branch coverage of the random simulation.
+This directory contains utility scripts for ToastyFS development and testing.
 
-## Prerequisites
+## Cluster Demo Script
+
+The `cluster_demo.sh` script allows you to easily spawn and manage a ToastyFS cluster for demo and testing purposes.
+
+### Usage
+
+```bash
+# Start a cluster with 3 chunk servers (default)
+./scripts/cluster_demo.sh start
+
+# Start a cluster with a custom number of chunk servers
+./scripts/cluster_demo.sh start 5
+
+# Check cluster status
+./scripts/cluster_demo.sh status
+
+# Stop the cluster
+./scripts/cluster_demo.sh stop
+
+# Clean all cluster data and logs
+./scripts/cluster_demo.sh clean
+```
+
+### What it does
+
+The script:
+- Builds ToastyFS if needed
+- Starts one metadata server (leader) on port 8080
+- Starts the specified number of chunk servers on ports 8081, 8082, etc.
+- Stores all process IDs for easy management
+- Captures logs to `cluster_logs/` directory
+- Stores data in `cluster_data/` directory
+
+All servers run in the background, making it easy to test the cluster with client applications.
+
+## Branch Coverage Measurement
+
+### Prerequisites
 
 The HTML report generation requires `lcov`:
 

scripts/cluster_demo.sh

@@ -0,0 +1,269 @@
+#!/bin/bash
+#
+# ToastyFS Cluster Demo Script
+# ===========================
+# This script allows you to easily spawn and manage a ToastyFS cluster for demo purposes.
+#
+# Usage:
+#   ./scripts/cluster_demo.sh start [num_chunk_servers]  - Start a cluster
+#   ./scripts/cluster_demo.sh stop                       - Stop the cluster
+#   ./scripts/cluster_demo.sh status                     - Show cluster status
+#   ./scripts/cluster_demo.sh clean                      - Clean data and log files
+#
+
+set -e
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+PROJECT_DIR="$(dirname "$SCRIPT_DIR")"
+PID_FILE="$PROJECT_DIR/.cluster_demo.pids"
+LOG_DIR="$PROJECT_DIR/cluster_logs"
+DATA_DIR="$PROJECT_DIR/cluster_data"
+
+METADATA_PORT=8080
+CHUNK_SERVER_BASE_PORT=8081
+
+# Colors for output
+RED='\033[0;31m'
+GREEN='\033[0;32m'
+YELLOW='\033[1;33m'
+BLUE='\033[0;34m'
+NC='\033[0m' # No Color
+
+print_info() {
+    echo -e "${BLUE}[INFO]${NC} $1"
+}
+
+print_success() {
+    echo -e "${GREEN}[SUCCESS]${NC} $1"
+}
+
+print_warning() {
+    echo -e "${YELLOW}[WARNING]${NC} $1"
+}
+
+print_error() {
+    echo -e "${RED}[ERROR]${NC} $1"
+}
+
+build_if_needed() {
+    if [ ! -f "$PROJECT_DIR/toastyfs.out" ] && [ ! -f "$PROJECT_DIR/toastyfs.exe" ]; then
+        print_info "Binary not found. Building ToastyFS..."
+        cd "$PROJECT_DIR"
+        make
+        print_success "Build complete"
+    fi
+}
+
+get_binary() {
+    if [ -f "$PROJECT_DIR/toastyfs.out" ]; then
+        echo "$PROJECT_DIR/toastyfs.out"
+    elif [ -f "$PROJECT_DIR/toastyfs.exe" ]; then
+        echo "$PROJECT_DIR/toastyfs.exe"
+    else
+        print_error "ToastyFS binary not found"
+        exit 1
+    fi
+}
+
+start_cluster() {
+    local num_chunk_servers=${1:-3}
+
+    if [ -f "$PID_FILE" ]; then
+        print_error "Cluster already running (PID file exists)"
+        print_info "Run '$0 stop' first or remove $PID_FILE if the cluster is not running"
+        exit 1
+    fi
+
+    build_if_needed
+    local binary=$(get_binary)
+
+    # Create directories
+    mkdir -p "$LOG_DIR"
+    mkdir -p "$DATA_DIR"
+
+    print_info "Starting ToastyFS cluster..."
+    print_info "  Metadata server: 127.0.0.1:$METADATA_PORT"
+    print_info "  Chunk servers: $num_chunk_servers"
+    echo
+
+    # Start metadata server
+    print_info "Starting metadata server on port $METADATA_PORT..."
+    local metadata_wal="$DATA_DIR/metadata.wal"
+    "$binary" --leader \
+        --addr 127.0.0.1 \
+        --port $METADATA_PORT \
+        --wal-file "$metadata_wal" \
+        > "$LOG_DIR/metadata.log" 2>&1 &
+
+    local metadata_pid=$!
+    echo "$metadata_pid" > "$PID_FILE"
+    print_success "Metadata server started (PID: $metadata_pid)"
+
+    # Wait a bit for metadata server to start
+    sleep 1
+
+    # Start chunk servers
+    for i in $(seq 1 $num_chunk_servers); do
+        local port=$((CHUNK_SERVER_BASE_PORT + i - 1))
+        local data_path="$DATA_DIR/chunk_server_$i/"
+
+        print_info "Starting chunk server $i on port $port..."
+        mkdir -p "$data_path"
+
+        "$binary" \
+            --addr 127.0.0.1 \
+            --port $port \
+            --path "$data_path" \
+            --remote-addr 127.0.0.1 \
+            --remote-port $METADATA_PORT \
+            > "$LOG_DIR/chunk_server_$i.log" 2>&1 &
+
+        local chunk_pid=$!
+        echo "$chunk_pid" >> "$PID_FILE"
+        print_success "Chunk server $i started (PID: $chunk_pid)"
+
+        # Small delay between starting servers
+        sleep 0.5
+    done
+
+    echo
+    print_success "Cluster started successfully!"
+    echo
+    print_info "Connect to the cluster using:"
+    print_info "  Address: 127.0.0.1"
+    print_info "  Port: $METADATA_PORT"
+    echo
+    print_info "View logs at: $LOG_DIR/"
+    print_info "Data stored at: $DATA_DIR/"
+    echo
+    print_info "To stop the cluster, run: $0 stop"
+}
+
+stop_cluster() {
+    if [ ! -f "$PID_FILE" ]; then
+        print_warning "No PID file found. Cluster may not be running."
+        exit 0
+    fi
+
+    print_info "Stopping ToastyFS cluster..."
+
+    local stopped=0
+    local failed=0
+
+    while IFS= read -r pid; do
+        if [ -n "$pid" ]; then
+            if kill -0 "$pid" 2>/dev/null; then
+                kill "$pid" 2>/dev/null && {
+                    print_success "Stopped process $pid"
+                    stopped=$((stopped + 1))
+                } || {
+                    print_error "Failed to stop process $pid"
+                    failed=$((failed + 1))
+                }
+            else
+                print_warning "Process $pid not running"
+            fi
+        fi
+    done < "$PID_FILE"
+
+    rm -f "$PID_FILE"
+
+    echo
+    print_success "Cluster stopped (Stopped: $stopped, Failed: $failed)"
+}
+
+show_status() {
+    if [ ! -f "$PID_FILE" ]; then
+        print_info "Cluster is NOT running"
+        exit 0
+    fi
+
+    print_info "Cluster status:"
+    echo
+
+    local running=0
+    local not_running=0
+    local line_num=0
+
+    while IFS= read -r pid; do
+        if [ -n "$pid" ]; then
+            line_num=$((line_num + 1))
+            local server_type="Chunk server $((line_num - 1))"
+            [ $line_num -eq 1 ] && server_type="Metadata server"
+
+            if kill -0 "$pid" 2>/dev/null; then
+                echo -e "  ${GREEN}●${NC} $server_type (PID: $pid) - ${GREEN}running${NC}"
+                running=$((running + 1))
+            else
+                echo -e "  ${RED}●${NC} $server_type (PID: $pid) - ${RED}not running${NC}"
+                not_running=$((not_running + 1))
+            fi
+        fi
+    done < "$PID_FILE"
+
+    echo
+    if [ $not_running -eq 0 ]; then
+        print_success "All $running servers are running"
+    else
+        print_warning "$running running, $not_running not running"
+    fi
+
+    if [ -d "$LOG_DIR" ]; then
+        echo
+        print_info "Log directory: $LOG_DIR"
+        print_info "Recent log files:"
+        ls -lht "$LOG_DIR" | head -n 6 | tail -n 5 | awk '{print "  " $9 " (" $5 ")"}'
+    fi
+}
+
+clean_data() {
+    if [ -f "$PID_FILE" ]; then
+        print_error "Cluster is running. Stop it first with: $0 stop"
+        exit 1
+    fi
+
+    print_warning "This will delete all cluster data and logs!"
+    read -p "Are you sure? (y/N) " -n 1 -r
+    echo
+
+    if [[ $REPLY =~ ^[Yy]$ ]]; then
+        print_info "Cleaning data and logs..."
+        rm -rf "$DATA_DIR"
+        rm -rf "$LOG_DIR"
+        print_success "Cleaned successfully"
+    else
+        print_info "Cancelled"
+    fi
+}
+
+# Main command dispatcher
+case "${1:-}" in
+    start)
+        start_cluster "${2:-3}"
+        ;;
+    stop)
+        stop_cluster
+        ;;
+    status)
+        show_status
+        ;;
+    clean)
+        clean_data
+        ;;
+    *)
+        echo "ToastyFS Cluster Demo Script"
+        echo
+        echo "Usage:"
+        echo "  $0 start [num_chunk_servers]  - Start a cluster (default: 3 chunk servers)"
+        echo "  $0 stop                       - Stop the cluster"
+        echo "  $0 status                     - Show cluster status"
+        echo "  $0 clean                      - Clean data and log files"
+        echo
+        echo "Examples:"
+        echo "  $0 start           # Start with 3 chunk servers"
+        echo "  $0 start 5         # Start with 5 chunk servers"
+        echo "  $0 status          # Check if cluster is running"
+        echo "  $0 stop            # Stop all servers"
+        exit 1
+        ;;
+esac