Change hostName to nodeName (#12)

This changes the `hostName` variable to be `nodeName` which better explains what it is supposed to capture.

Author: styfle

README.md

@@ -15,8 +15,8 @@ const tracer = new Tracer(
     serviceName: 'my-first-service',
     environment: process.env.ENVIRONMENT,
     dc: process.env.DC,
-    podName: process.env.PODNAME,
-    hostName: process.env.HOSTNAME,
+    podName: process.env.POD_NAME,
+    nodeName: process.env.NODE_NAME,
     sampler: new DeterministicSampler(process.env.TRACE_SAMPLE_RATE),
   },
   {
@@ -85,7 +85,8 @@ But a better solution is to use the `setupHttpTracing` helper function like the
 
 ```ts
 async function handler(req: IncomingMessage, res: ServerResponse) {
-  const { spanContext, fetch } = setupHttpTracing({ tracer, req, res });
+  const spanContext = setupHttpTracing({ tracer, req, res });
+  const fetch = setupFetchTracing({ spanContext });
   await sleep(100, spanContext);
   const output = await fetch(upstreamUrl);
   res.write(output);

examples/db-example.ts

@@ -11,8 +11,8 @@ const tracer = new Tracer(
     serviceName: 'db-example',
     environment: process.env.ENVIRONMENT,
     dc: process.env.DC,
-    podName: process.env.PODNAME,
-    hostName: process.env.HOSTNAME,
+    podName: process.env.POD_NAME,
+    nodeName: process.env.NODE_NAME,
     sampler: new DeterministicSampler(process.env.TRACE_SAMPLE_RATE),
   },
   {

examples/routing-example.ts

@@ -14,8 +14,8 @@ const tracer = new Tracer(
     serviceName: 'routing-example',
     environment: process.env.ENVIRONMENT,
     dc: process.env.DC,
-    podName: process.env.PODNAME,
-    hostName: process.env.HOSTNAME,
+    podName: process.env.POD_NAME,
+    nodeName: process.env.NODE_NAME,
     sampler: new DeterministicSampler(process.env.TRACE_SAMPLE_RATE),
   },
   {

src/shared.ts

@@ -8,7 +8,7 @@ export interface TracerOptions {
   environment?: string;
   dc?: string;
   podName?: string;
-  hostName?: string;
+  nodeName?: string;
   sampler?: SamplerBase;
 }
 

src/span.ts

@@ -74,15 +74,15 @@ export class Span {
       environment,
       dc,
       podName,
-      hostName,
+      nodeName,
     } = this.tracerOptions;
     this.event.addField('duration_ms', duration);
     this.event.addField('name', this.name);
     this.event.addField('service_name', serviceName);
     this.event.addField('environment', environment);
     this.event.addField('dc', dc);
     this.event.addField('pod_name', podName);
-    this.event.addField('host_name', hostName);
+    this.event.addField('node_name', nodeName);
     this.event.addField('trace.trace_id', this.traceId);
     this.event.addField('trace.span_id', this.spanId);
     this.event.addField('trace.parent_id', this.parentId);