demo

DAPR Demo application

Installation

Configure and lauch minikube

minikube config set memory 8000
minikube config set cpus 4
minikube config set kubernetes-version 1.23.3
minikube start

Once minikube is running enable the ingress controller

minikube addons enable ingress

Read out the IP address of minikube with

minikube ip

and write those entries to your /etc/hosts

<minikube-ip> dapr.minikube backend.minikube grafana.minikube prometheus.minikube

In the subdirectory terraform run terraform apply, but first only for the resources that create CRDs

terraform apply -target=helm_release.kube-prometheus-stack -target=helm_release.dapr-system

Then create everything else

terraform apply

This will install

• DAPR in the namespace dapr-system
• The business services
• Monitoring

DAPR

DAPR should be available under the http://dapr.minikube and show our services

and the following components

Number

Number will return an incrementing number

curl http://backend.minikube/number

This call should return an incrementing value

Checkout

Create a checkout. It does two things

• Call the number service to obtain a number
• Create a message to the topic checkout

curl -XPOST http://backend.minikube/checkout

Order

Subscribed to the topic checkout

curl http://backend.minikube/order

Redis

Redis is used for the persistence

kubectl -n messaging exec -ti redis-master-0 -- redis-cli --pass redis keys \* 

State

Redis is a state store

kubectl -n messaging exec -ti redis-master-0 -- redis-cli --pass redis hgetall 'number||orderNumber'

should return something like

1) "data"
2) "5"
3) "version"
4) "5"

Stream

Streams are used for sending asynchrous messages.

kubectl -n messaging exec -ti redis-master-0 -- redis-cli --pass redis xrange checkout - +

should give you some output like

1) 1) "1654699830640-0"
   2) 1) "data"
      2) "{\"datacontenttype\":\"text/plain\",\"source\":\"checkout\",\"type\":\"com.dapr.event.sent\",\"tracestate\":\"\",\"traceparent\":\"00-22295cc10dd4eb53ae9879363d0e4943-11aac0459158b429-00\",\"data\":\"1\",\"id\":\"e20734c9-607d-4b11-94fd-bd735c43bea4\",\"specversion\":\"1.0\",\"topic\":\"checkout\",\"pubsubname\":\"pubsub\",\"traceid\":\"00-22295cc10dd4eb53ae9879363d0e4943-11aac0459158b429-00\"}"
2) 1) "1654699925789-0"
   2) 1) "data"
      2) "{\"data\":\"2\",\"source\":\"checkout\",\"pubsubname\":\"pubsub\",\"traceparent\":\"00-7644aab7b8b858c9f99883fe6f6b8b03-07930bba2d1eccc5-00\",\"tracestate\":\"\",\"topic\":\"checkout\",\"traceid\":\"00-7644aab7b8b858c9f99883fe6f6b8b03-07930bba2d1eccc5-00\",\"id\":\"763d3813-887c-4bc1-a50b-94a83f28cfbc\",\"specversion\":\"1.0\",\"datacontenttype\":\"text/plain\",\"type\":\"com.dapr.event.sent\"}"

Tips

Restart all business services pods

kubectl -n backend get deployments | grep -v NAME | awk '{print $1}' | xargs kubectl -n backend rollout restart deployment