Feature/opentelemetry (#89)

* initial adds for otel tracing

* initial basic testing

* basic tracing for incoming calls

* linting

* add traceId to the webhook params

* trace webhook calls

* tracing: add new commands as tags when receiving async commands over websocket

* tracing new commands

* add summary for config verb

* trace async commands

* bugfix: undefined ref

* tracing: give time for final webhooks before closing root span

* tracing bugfix: span for background gather was not ended

* tracing - minor tag changes

* tracing - add span atttribute for reason call ended

* trace call status webhooks, add app version to trace output

* config: add support for automatically re-enabling

* env var to customize service name in tracing UI

* config: change to use 'sticky' attribute to re-enable bargein automatically

* fix warnings

* when adulting create a new root span

* when background gather triggers bargein via vad clear queue of tasks

* additional trace attributes for dial and refer

* fix dial tracing

* add better summary for dial

* fix prev commit

* add exponential backoff to WsRequestor reconnection logic

* add calling number to log metadata, as this will be frequently the key data given for troubleshooting

* add accountSid to log metadata

* make handshake timeout for ws connections configurable with default 1.5 secs

* rename env var

* fix bug prev checkin

* logging fixes

* consistent env naming

lib/utils/call-tracer.js

@@ -0,0 +1,63 @@
+const {context, trace} = require('@opentelemetry/api');
+const {Dialog} = require('drachtio-srf');
+class RootSpan {
+  constructor(callType, req) {
+    let tracer, callSid, linkedSpanId;
+
+    if (req instanceof Dialog) {
+      const dlg = req;
+      tracer = dlg.srf.locals.otel.tracer;
+      callSid = dlg.callSid;
+      linkedSpanId = dlg.linkedSpanId;
+    }
+    else {
+      tracer = req.srf.locals.otel.tracer;
+      callSid = req.locals.callSid;
+    }
+    this._span = tracer.startSpan(callType || 'incoming-call');
+    if (req instanceof Dialog) {
+      const dlg = req;
+      this._span.setAttributes({
+        linkedSpanId,
+        callId: dlg.sip.callId
+      });
+    }
+    else {
+      this._span.setAttributes({
+        callSid,
+        accountSid: req.get('X-Account-Sid'),
+        applicationSid: req.locals.application_sid,
+        callId: req.get('Call-ID'),
+        externalCallId: req.get('X-CID')
+      });
+    }
+
+    this._ctx = trace.setSpan(context.active(), this._span);
+    this.tracer = tracer;
+  }
+
+  get context() {
+    return this._ctx;
+  }
+
+  get traceId() {
+    return this._span.spanContext().traceId;
+  }
+
+  setAttributes(attrs) {
+    this._span.setAttributes(attrs);
+  }
+
+  end() {
+    this._span.end();
+  }
+
+  startChildSpan(name, attributes) {
+    const span = this.tracer.startSpan(name, attributes, this._ctx);
+    const ctx = trace.setSpan(context.active(), span);
+    return {span, ctx};
+  }
+}
+
+module.exports = RootSpan;
+