README.md
# RequestTraceId
A small plug similar to [`Plug.RequestId`](https://hexdocs.pm/plug/Plug.RequestId.html) except that it appends ids allowing for simple request tracing. Because of this distinction the header used is instead `X-Request-Trace-Id` and the following terminology is adopted (adapted from [Zipkin](zipkin.io)):
**span-id**
* A randomized id generated for each client/server request/response.
**request-trace-id**
* A semicolon delimited string of all span-ids generated during the lifecycle of a single upstream request.
## Installation
If [available in Hex](https://hex.pm/docs/publish), the package can be installed
by adding `request_trace_id` to your list of dependencies in `mix.exs`:
```elixir
def deps do
[
{:request_trace_id, "~> 0.1.0"}
]
end
```
## Usage
To use it, just plug it into the desired module:
```
plug RequestTraceId
```