This example server renders a simple hello page and writes both the server-side and client side spans for the initial page load to the OpenCensus agent.

To run this example in local development mode, you will need to run the OpenCensus agent.

First set your GOPATH environment variable and then install the agent by running:

go get -d github.com/census-instrumentation/opencensus-service

Then create a config.yaml file following the Configuration instructions for the agent. You will need to have the opencensus receiver set up on the default port of 55678, and you will need at least one exporter so you can see the traces that are generated. For example, your config file could look like this:

receivers:
  opencensus:
    address: "127.0.0.1:55678"
    cors_allowed_origins:
      - http://localhost:*
exporters:
  # Pick and configure an exporter e.g. stackdriver, zipkin, aws-xray, honeycomb

Then in the same folder as your config.yaml run the agent with this command:

GO111MODULE=on go run github.com/census-instrumentation/opencensus-service/cmd/ocagent

Then within your opencensus-web folder run the local webpack server for the opencensus-scripts package to serve the OpenCensus web scripts:

cd packages/opencensus-web-scripts
npm run start:webpack-server

That will start the webpack development server on localhost:8080.

Now you can run this example server with the following commands from within your opencensus-web folder:

cd examples/initial_load
go run server.go

Now visit http://localhost:8000/index.html in your browser to see the hello world page render. If you look in the browser developer tools network tab, you should see an XHR that writes trace spans to the OpenCensus agent. Then go to the trace viewer for the exporter you set up and view the trace of your initial page load. It will be named Nav./index.html (or just Nav./ if you left off the actual index.html part when you visited the URL).

Install gcloud. Then run gcloud components install kubectl to install kubectl.

To create a cluster with the following commands:

gcloud services enable container.googleapis.com
gcloud container clusters create opencensus-web-demo --enable-autoupgrade --num-nodes=1 --zone=us-central1-a

You also need to enable Google Container Registry (GCR) on your GCP project and configure the docker CLI to authenticate to GCR:

gcloud services enable containerregistry.googleapis.com
gcloud auth configure-docker -q

To deploy the agent, run the following commands:

# Get the project you are using with gcloud
PROJECT_ID="$(gcloud config list --format 'value(core.project)')"

# Substitute the project ID in the k8s config and deploy it
cat ./kubernetes/oc-agent-cors.template.yaml | \
  sed "s/{{PROJECT-ID}}/$PROJECT_ID/" | \
  kubectl apply -f -

Note that this uses the omnition/opencensus-agent container from the Docker Hub. You can also build your own container by following the OpenCensus Agent docs.

First build the OpenCensus Web scripts that will be deployed with the application:

npm run build:prod --prefix=../../packages/opencensus-web-scripts
mkdir -p static
cp ../../packages/opencensus-web-scripts/dist/*.js ./static

Then build the server container and push it to GCR:

PROJECT_ID="$(gcloud config list --format 'value(core.project)')"
docker build . -t gcr.io/$PROJECT_ID/oc-web-initial-load:latest
gcloud docker -- push gcr.io/$PROJECT_ID/oc-web-initial-load:latest

Run the command kubectl get svc oc-agent-service to check if the EXTERNAL-IP column has been filled in. If it is still pending, then wait a bit and run it again until it's available.

Once the agent has an external IP, you can deploy the example service that uses it by running the following commands:

PROJECT_ID="$(gcloud config list --format 'value(core.project)')"
AGENT_IP="$(kubectl get svc oc-agent-service \
    -o=custom-columns="IP ADDRESS:.status.loadBalancer.ingress[*].ip" | \
    tail -n 1)"
cat ./kubernetes/initial-load-demo.template.yaml | \
  sed "s/{{PROJECT-ID}}/$PROJECT_ID/; s/{{AGENT-IP}}/$AGENT_IP/" | \
  kubectl apply -f -

Then run kubectl get svc oc-web-initial-load-service to see the external IP address for the demo app, which you can then visit in your browser.

You can then view traces in the Stackdriver Trace console in GCP. The traces will be named Nav./.