Feature/trace propagation (#96)

* add b3 header for trace propagation on initial webhook

* logging

* add tracing context to all webhooks

* Add span parameter to Task.getTracingPropagation. Pass proper span to getTracingPropagation calls in Task methods to propagate the proper spanId (#91)

* some tracing cleanup

* bugfix: azure stt results need to be ordered by confidence level before processing (#92)

* fix assertion

* bugfix: vad was not enabled on config verb, restart STT on empty transcript in gather

* gather: dont send webhook if call is gone

* rest outdial: handle 302 redirect so we can later cancel request if needed (#95)

* gather: restart if we get an empty transcript (looking at you, Azure)

Co-authored-by: javibookline <98887695+javibookline@users.noreply.github.com>

lib/utils/call-tracer.js

@@ -44,6 +44,21 @@ class RootSpan {
     return this._span.spanContext().traceId;
   }
 
+  get spanId() {
+    return this._span.spanContext().spanId;
+  }
+
+  get traceFlags() {
+    return this._span.spanContext().traceFlags;
+  }
+
+  getTracingPropagation(encoding) {
+    // TODO: support encodings beyond b3 https://github.com/openzipkin/b3-propagation
+    if (this._span  && this.traceId !== '00000000000000000000000000000000') {
+      return `${this.traceId}-${this.spanId}-1`;
+    }
+  }
+
   setAttributes(attrs) {
     this._span.setAttributes(attrs);
   }

lib/utils/http-requestor.js

@@ -49,7 +49,7 @@ class HttpRequestor extends BaseRequestor {
    * @param {string} [hook.password] - if basic auth is protecting the endpoint
    * @param {object} [params] - request parameters
    */
-  async request(type, hook, params) {
+  async request(type, hook, params, httpHeaders = {}) {
     assert(HookMsgTypes.includes(type));
     const payload = params ? snakeCaseKeys(params, ['customerData', 'sip']) : null;
     const url = hook.url || hook;
@@ -64,8 +64,8 @@ class HttpRequestor extends BaseRequestor {
     let buf;
     try {
       const sigHeader = this._generateSigHeader(payload, this.secret);
-      const headers = {...sigHeader, ...this.authHeader};
-      //this.logger.info({url, headers}, 'send webhook');
+      const headers = {...sigHeader, ...this.authHeader, ...httpHeaders};
+      this.logger.debug({url, headers}, 'send webhook');
       buf = this._isRelativeUrl(url) ?
         await this.post(url, payload, headers) :
         await bent(method, 'buffer', 200, 201, 202)(url, payload, headers);

lib/utils/ws-requestor.js

@@ -33,7 +33,7 @@ class WsRequestor extends BaseRequestor {
    * @param {string} [hook.password] - if basic auth is protecting the endpoint
    * @param {object} [params] - request parameters
    */
-  async request(type, hook, params) {
+  async request(type, hook, params, httpHeaders = {}) {
     assert(HookMsgTypes.includes(type));
     const url = hook.url || hook;
 
@@ -48,7 +48,7 @@ class WsRequestor extends BaseRequestor {
     if (this._isAbsoluteUrl(url) && url.startsWith('http')) {
       this.logger.debug({hook}, 'WsRequestor: sending a webhook (HTTP)');
       const requestor = new HttpRequestor(this.logger, this.account_sid, hook, this.secret);
-      return requestor.request(type, hook, params);
+      return requestor.request(type, hook, params, httpHeaders);
     }
 
     /* connect if necessary */
@@ -73,12 +73,14 @@ class WsRequestor extends BaseRequestor {
     assert.ok(url, 'WsRequestor:request url was not provided');
 
     const msgid = short.generate();
+    const b3 = httpHeaders?.b3 ? {b3: httpHeaders.b3} : {};
     const obj = {
       type,
       msgid,
       call_sid: this.call_sid,
       hook: type === 'verb:hook' ? url : undefined,
-      data: {...payload}
+      data: {...payload},
+      ...b3
     };
 
     //this.logger.debug({obj}, `websocket: sending (${url})`);