Opentracing plugin for NkSERVER
Each package or service based on nkserver can activate opentracing capabilities by inserting this plugin.
Service must define the key 'opentrace_rules' (see nkserver_ot_rules), with a string implementing the filtering rules (created by FIFO's otters project). These rules are compiled on plugin start and at each update, and applied to generated all spans to decide if they must be sent or discarded.
There are a reach set of ways to generate spans (see nkserver_ot).
Spans, we finished, are sent to an aggregator gen_server process, that sends them in batches to the Zipkin-compatible server.
This project is based on otter and otters projects.
Application-specific keys configure the zipking url and send interval (see shell.config for a sample).