Initial commit: mod_reqin_log Apache module

Features:
- JSON logging of HTTP requests to Unix domain socket
- Configurable HTTP headers logging (flat JSON structure)
- Header value truncation and count limits
- Automatic reconnect on socket disconnection
- Error reporting with throttling

Configuration directives:
- JsonSockLogEnabled: Enable/disable logging
- JsonSockLogSocket: Unix socket path
- JsonSockLogHeaders: List of headers to log
- JsonSockLogMaxHeaders: Maximum headers to log
- JsonSockLogMaxHeaderValueLen: Max header value length
- JsonSockLogReconnectInterval: Reconnect delay
- JsonSockLogErrorReportInterval: Error log throttle

Includes:
- Module source code (src/)
- Unit and integration tests (tests/, scripts/)
- Documentation (README.md, architecture.yml)
- Build configuration (CMakeLists.txt, Makefile)
- Packaging (deb/rpm)

Co-authored-by: Qwen-Coder <qwen-coder@alibabacloud.com>

conf/mod_reqin_log.conf

@@ -0,0 +1,27 @@
+# mod_reqin_log example configuration
+# Load this configuration in your Apache httpd.conf or a separate included file
+
+# Load the module (adjust path as needed)
+LoadModule reqin_log_module modules/mod_reqin_log.so
+
+# Enable mod_reqin_log
+JsonSockLogEnabled On
+
+# Unix domain socket path for JSON log output
+JsonSockLogSocket "/var/run/mod_reqin_log.sock"
+
+# HTTP headers to include in the JSON log
+# Warning: Be careful not to log sensitive headers like Authorization, Cookie, etc.
+JsonSockLogHeaders X-Request-Id X-Trace-Id User-Agent Referer X-Forwarded-For
+
+# Maximum number of headers to log (from the configured list)
+JsonSockLogMaxHeaders 10
+
+# Maximum length of each header value (longer values are truncated)
+JsonSockLogMaxHeaderValueLen 256
+
+# Minimum delay between reconnect attempts to the Unix socket (seconds)
+JsonSockLogReconnectInterval 10
+
+# Minimum delay between error messages to Apache error_log (seconds)
+JsonSockLogErrorReportInterval 10