Lighting Development & Debugging Guide

This guide compiles common workflows, debugging tips, and verification techniques for working on the Lighting web framework.

1. Verifying HTTP Keep-Alive

Validating persistent connection reuse (Keep-Alive) is critical when developing network services. The simplest and most reliable way to test this is with curl.

1.1 Requesting Multiple URLs in a Single Command (Recommended)

Specify multiple URLs in a single curl invocation with verbose mode (-v):

curl -v http://127.0.0.1:7000/ http://127.0.0.1:7000/

When Keep-Alive is operating correctly, two key markers appear in the verbose output:

1. At the end of the first request:

   < HTTP/1.1 200 OK
   < Connection: keep-alive
   < Content-Length: 46
   <
   * Connection #0 to host 127.0.0.1 left intact   <-- Connection remains open
   

2. At the beginning of the second request:

   * Re-using existing connection with host 127.0.0.1 <-- Reuses TCP socket, no new handshake
   > GET / HTTP/1.1
   > Host: 127.0.0.1:7000
   

1.2 Testing Sequential Endpoints with --next

To test different paths or endpoints over the exact same persistent TCP connection:

curl -v http://127.0.0.1:7000/hello/alice --next http://127.0.0.1:7000/hello/bob

Both HTTP requests are transmitted sequentially across the same socket, with Re-using existing connection displayed before the second request.

1.3 Negative Verification (Connection: close)

To confirm proper behavior when the client requests disconnection via Connection: close:

curl -v -H "Connection: close" http://127.0.0.1:7000/ http://127.0.0.1:7000/

Both server and client acknowledge the termination:

• < Connection: close
• * Closing connection 0
• The subsequent request triggers a fresh TCP three-way handshake (* Connected to ...).