cpp-shared-lib

C++ Shared Library Demo

This demo shows one C++ process loading a Rust shared library and sending OTLP logs into ljd over gRPC.

The path is:

C++ appliance -> liblogjet.so -> OTLP/gRPC -> ljd -> .logjet file -> ljx view

Build First

From the project root:

cargo build -p ljd -p ljx -p liblogjet

You also need g++ available locally because the demo compiles the C++ example on demand.

Run

From this directory:

./run-demo.sh

What It Does

The script:

1. builds the example C++ logger
2. starts file-backed ljd on 127.0.0.1:4317
3. loads liblogjet.so through dlopen
4. sends 25 OTLP log records from C++ by default
5. opens ljx view on the resulting ./logs/cpp-demo.logjet

Notes

• the library now supports both OTLP/HTTP and OTLP/gRPC constructors
• this demo specifically uses OTLP/gRPC
• the FFI API is intentionally small: endpoint, service name, timestamp, severity, message body, and string attributes
• those key/value pairs become OTLP LogRecord.attributes, which is the standard OTel metadata field for log records
• if the appliance already has JSON metadata, the better long-term shape is to flatten that JSON into separate attributes where possible; a raw JSON blob can still be sent as one string attribute when needed
• the demo uses a local symlink named liblogjet.so that points at Cargo's built shared object