OpenTracing API for Lua

Lua implementation of the OpenTracing API http://opentracing.io

Required Reading

In order to understand the Lua platform API, one must first be familiar with the OpenTracing project and terminology more generally.

API overview for those adding instrumentation

Everyday consumers of this opentracing package really only need to worry about a couple of key abstractions: the start_span function, the Span interface, and binding a Tracer at initialization-time. Here are code snippets demonstrating some important use cases.

Starting an empty trace by creating a "root span"

It's always possible to create a "root" Span with no parent or other causal reference.

    function xyz()
        ...
        tracer = --[[ Some Tracer ]]
        span = tracer:start_span("operation_name")
        -- Do some work
        span:finish()
        ...
    end

Creating a (child) Span given an existing (parent) Span

    function qrz(parent_span)
        ...
        tracer = --[[ Some Tracer ]]
        span = tracer:start_span(
          "operation_name",
          {["references"] = {{"child_of", parent_span:context()}}})
        -- Do some work
        span:finish()
        ...
    end

Inject Span context into a table

    tracer = --[[ Some Tracer ]]
    carrier = {}
    span = tracer:start_span('abc')
    tracer:http_headers_inject(span:context(), carrier)

Extract Span context from a table

    tracer = --[[ Some Tracer ]]
    carrier = --[[ Some carrier ]]
    span_context = tracer:http_headers_extract(carrier)

API compatibility

For the time being, "mild" backwards-incompatible changes may be made without changing the major version number. As OpenTracing and opentracing-cpp mature, backwards compatibility will become more of a priority.

License

By contributing to opentracing.lua, you agree that your contributions will be licensed under its Apache 2.0 License.

opentracing / opentracing-lua