feat: add propagation to config and tracer

Author: silva-fabio

packages/opencensus-core/src/index-types.ts

@@ -20,5 +20,6 @@ export * from './trace/model/types';
 export * from './trace/config/types';
 export * from './trace/sampler/types';
 export * from './trace/instrumentation/types';
+export * from './trace/propagation/types';
 export * from './exporters/types';
 export * from './common/types';

packages/opencensus-core/src/trace/config/types.ts

@@ -17,6 +17,7 @@
 import {Logger} from '../../common/types';
 import {Exporter} from '../../exporters/types';
 import {PluginNames} from '../instrumentation/types';
+import {Propagation} from '../propagation/types';
 
 /** Interface configuration for a buffer. */
 export interface BufferConfig {
@@ -36,6 +37,8 @@ export interface TracerConfig {
   ignoreUrls?: Array<string|RegExp>;
   /** A logger object  */
   logger?: Logger;
+  /** A propagation instance */
+  propagation?: Propagation;
 }
 
 /** Available configuration options. */

packages/opencensus-core/src/trace/model/tracer.ts

@@ -18,6 +18,7 @@ import * as logger from '../../common/console-logger';
 import * as loggerTypes from '../../common/types';
 import * as cls from '../../internal/cls';
 import * as configTypes from '../config/types';
+import {Propagation} from '../propagation/types';
 import {Sampler} from '../sampler/sampler';
 import * as samplerTypes from '../sampler/types';
 
@@ -64,6 +65,11 @@ export class Tracer implements types.Tracer {
     this.contextManager.set('rootspan', root);
   }
 
+  /** A propagation instance */
+  get propagation(): Propagation {
+    return this.config ? this.config.propagation : null;
+  }
+
   /**
    * Starts a tracer.
    * @param config A tracer configuration object to start a tracer.

packages/opencensus-core/src/trace/model/types.ts

@@ -16,6 +16,7 @@
 
 import * as loggerTypes from '../../common/types';
 import * as configTypes from '../config/types';
+import {Propagation} from '../propagation/types';
 import * as samplerTypes from '../sampler/types';
 
 
@@ -222,6 +223,9 @@ export interface Tracer extends OnEndSpanEventListener {
   /** A configuration for starting the tracer */
   logger: loggerTypes.Logger;
 
+  /** A propagation instance */
+  readonly propagation: Propagation;
+
   /** Get the eventListeners from tracer instance */
   readonly eventListeners: OnEndSpanEventListener[];