diazjf/meow-micro

Contains MicroServices which send and receive cat names.

Meow Micro 🐈

Contains MicroServices which send and receive cat names. The meow-client accepts requests via a REST API and uses GRPC to communicate with the meow-server.

It is used in the Distributed Tracing tutorial Setting up Distributed Tracing in Kubernetes with OpenTelemetry, Jaeger, and Ingress-NGINX, which goes over:

• Ingress-Nginx Distributed Tracing
• Instrumenting MicroServices
• Viewing Traces

Running Locally

In order to run locally simply perform the following:

1. Install Dependencies

   $ go install ...
   

2. Start the server

   $ go run server/server.go
   

3. Start the client in another terminal

   $ go run client/client.go
   

4. Send a Request to the client

   $ curl 127.0.0.1:5002 -X POST -d '{"body": "Meow-Mixer"}'
   

5. View the output of both in the terminal

Deploying to Kubernetes

I have included deployment scripts for deploying to Docker-Desktop Kubernetes. There are some pre-requisites required before running the below:

• Docker-Desktop
• Helm v3

1. Install Ingress

$ kubectl apply -f https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v0.45.0/deploy/static/provider/cloud/deploy.yaml

2. Install Jaeger-All-In-One

$ kubectl apply -f jaeger/jaeger-all-in-one.yaml

3. Update Ingress Config-Map

$ echo '
  apiVersion: v1
  kind: ConfigMap
  data:
    enable-opentracing: "true"
    jaeger-collector-host: jaeger-agent.default.svc.cluster.local              
  metadata:
    name: ingress-nginx-controller
    namespace: ingress-nginx
  ' | kubectl replace -f -

4. Build Docker Images

$ make build

5. Install via Helm Chart

$ make install

Testing Deployment Tracing

1. Send a Request to the application

$ curl http://localhost/meow -X POST -d '{"name": "Meow-Mixer"}'

2. Open Jaeger UI

$ open http://localhost:8081

3. See the Traces

Troubleshooting

1. Check items are correctly deployed

$ kubectl get all
$ kubectl get all -n ingress-nginx

2. View the logs

$ kubectl logs -n ingress-nginx <ingress-controller>
$ kubectl logs <meow-server>
$ kubectl logs <meow-client>

3. Exec into the meow-client pod

$ kubectl exec -it <meow-client> -- bash

4. install grpcurl

$ go get github.com/fullstorydev/grpcurl/...
$ go install github.com/fullstorydev/grpcurl/cmd/grpcurl

5. Verify you can access the GRPC Service

$ grpcurl -d '{"body": "Meow-Mixer"}' -plaintext meow-server-svc:5001 chat.ChatService/SayHello