rebuild-addon

name	rebuild-addon
description	Rebuild the C++ native addon after making changes to http_checker.cpp
allowed-tools	Bash(npm run*), Bash(node-gyp*), Bash(docker*), Bash(cp*), Bash(ls*), Read, Glob, Grep

Rebuild Native Addon

Use this skill after making changes to the C++ native addon (src/http_checker.cpp or src/http_checker.h).

Usage

• /rebuild-addon - Rebuild the addon and restart Jetmon
• /rebuild-addon docker - Rebuild inside Docker container
• /rebuild-addon test - Rebuild and run a quick test

Quick Reference

Using npm Script (Recommended)

npm run rebuild-run

This runs node-gyp rebuild, copies the addon to lib/, and starts Jetmon.

Manual Build

node-gyp rebuild
cp build/Release/jetmon.node lib/
node lib/jetmon.js

Docker Build

docker compose exec jetmon npm run rebuild-run

Or manually inside the container:

docker compose exec jetmon bash
cd /jetmon
node-gyp rebuild
cp build/Release/jetmon.node lib/
node lib/jetmon.js

Build Verification

After building, verify the addon loads correctly:

node -e "require('./lib/jetmon.node'); console.log('Addon loaded successfully');"

Testing the Addon

Quick HTTP Check Test

Create a test script:

// lib/test-addon.js
var checker = require( './jetmon.node' );

checker.http_check( 'https://wordpress.com', 80, 0, function( index, rtt, http_code, error_code ) {
    console.log( 'Index:', index );
    console.log( 'RTT (microseconds):', rtt );
    console.log( 'HTTP Code:', http_code );
    console.log( 'Error Code:', error_code );
    process.exit( 0 );
});

Run it:

node lib/test-addon.js

Expected Output

• index: The index passed to the check (0 in this case)
• rtt: Round-trip time in microseconds
• http_code: HTTP response code (200 for success)
• error_code: 0 for success, non-zero for errors

Error Codes

Code	Meaning
0	Success
1	Connection failed
2	Timeout
3	SSL error
4	DNS resolution failed
5	Too many redirects

C++ Source Files

File	Purpose
src/http_checker.cpp	Main HTTP checking implementation
src/http_checker.h	Header with class definition
binding.gyp	Node-gyp build configuration

Common Issues

Build Errors

Missing OpenSSL headers:

fatal error: openssl/ssl.h: No such file or directory

Solution: Install OpenSSL development package:

# macOS
brew install openssl

# Ubuntu/Debian
apt-get install libssl-dev

Node version mismatch: If you see ABI version errors, clean and rebuild:

node-gyp clean
node-gyp rebuild

Runtime Errors

Addon not found:

Error: Cannot find module './jetmon.node'

Solution: Copy the built addon:

cp build/Release/jetmon.node lib/

Symbol errors: Usually indicates Node.js version changed. Rebuild the addon.

Debugging C++ Code

Enable Debug Output

In src/http_checker.cpp, set:

#define DEBUG_MODE 1

Debug output goes to stderr.

Memory Debugging

For memory leaks, use Valgrind (Linux):

valgrind --leak-check=full node lib/jetmon.js

Build Configuration

The binding.gyp file configures the build:

{
  "targets": [{
    "target_name": "jetmon",
    "sources": ["src/http_checker.cpp"],
    "include_dirs": ["<!(node -e \"require('nan')\")"],
    "libraries": ["-lssl", "-lcrypto"]
  }]
}

Key settings:

• Uses NAN (Native Abstractions for Node.js) for compatibility
• Links against OpenSSL for HTTPS support

After Rebuilding

1. Test the addon with a simple HTTP check
2. Start Jetmon and verify workers spawn correctly
3. Monitor logs for any C++ errors
4. Check memory usage to ensure no new leaks