PCF Metrics Node Tracer Example

This is a nodejs repository with three apps: shopping-cart, orders, and payments. These apps use Zipkin to trace the calls between them. The traces can then be viewed in PCF-Metrics.

Creating your own tracer apps

Most of the app code is standard nodejs application code independent of tracing.

To add tracing the following steps are neccesary:

• add the zipkin js express middleware

import express from 'express'
import {expressMiddleware as zipkin} from 'zipkin-instrumentation-express';

const app = new Express();

const ctxImpl = new ExplicitContext();
const recorder = new ConsoleRecorder();
const tracer = new Tracer({ctxImpl, recorder});

app.use(zipkin({tracer, serviceName: 'my service'}));

• instrument http requests that use fetch. Install and use zipkin-instrumentation-fetch.

Parent Span Id will show up in the router logs even without this property.

Using the example apps

DEPLOY

To use the script, you must login as a user that has the ability to assign space permissions and make spaces. It will create a given shopping-cart, orders, and payments app that can be used to preview an example trace.

To deploy, use the script ./scripts/deploy.sh. Set the SUFFIX ENV var to a unique identifier for your tracer applications.

For example

cf login
SUFFIX=test ./scripts/deploy.sh

CURL APPS

Curl the /checkout endpoint for the given shopping cart app.

For example

curl shopping-cart-test.cfapps.io/checkout

CLEANUP

To cleanup, use the script ./scripts/cleanup.sh. Set the SUFFIX ENV var to the same identifier used for deployment.

For example

cf login
SUFFIX=test ./scripts/cleanup.sh

Viewing in PCF-Metrics

To view the trace in PCF-Metrics, go to the shopping-cart app in PCF-Metrics. Find the log corresponding to the /checkout endpoint and click the 'View in Trace Explorer' icon.

For example