This is a sample application demoing using CloudState to build a chat application in Java.
It supports 2 features - user presence and user's friends
The application has two components, presence stateful function, which uses a vote CRDT to store whether a user is currently online or not, and friends stateful function, which uses a ORSet CRDT to store a list of user's friends. It also relies on a chat application, that serves a UI.
The UI is designed to allow connecting as multiple users in one browser window, this is for demonstration purposes, to make it straight forward to see real time interactions, serverside pushes etc, without needing to open many browser tabs.
To run in Kubernetes on GCP, you need create a cluster and install Istio version 1.4.6 To do this I was following approach outlined in this blog post (without Knative). The actual script is copied from here
Create cluster
deploy/cluster/create-gke-cluster
Install Istio. Istio release 1.4.7 is here. Go to the Istio directory and run following command:
bin/istioctl manifest apply --set profile=default
To add Kiali and grafana run:
bin/istioctl manifest apply --set values.grafana.enabled=true --set values.kiali.enabled=true
If you can't access Kiali, run the following:
kubectl create secret generic kiali -n istio-system --from-literal=username=admin --from-literal=passphrase=admin
Add a namespace label to instruct Istio to automatically inject Envoy sidecar proxies when you deploy your application
kubectl label namespace default istio-injection=enabled
To install CloudState, run the following:
kubectl create namespace cloudstate
kubectl apply -n cloudstate -f https://raw.githubusercontent.com/cloudstateio/cloudstate/master/operator/cloudstate.yaml
Now, you can install the chat, friends and presence services by running the following:
kubectl apply -f /Users/boris/Projects/samples-java-chat/deploy/chat.yaml
kubectl apply -f /Users/boris/Projects/samples-java-chat/deploy/friends.yaml
kubectl apply -f /Users/boris/Projects/samples-java-chat/deploy/presence.yaml
install Istio virtual services
kubectl apply -f /Users/boris/Projects/samples-java-chat/deploy/chatVirtualService.yaml
You may wish to scale the presence service up, to see that it works on multiple nodes:
kubectl scale deploy/presence-deployment --replicas 3
kubectl scale deploy/friends-deployment --replicas 3
Run
kubectl get svc istio-ingressgateway -n istio-system
to get external IP
Go to http://<externalIP>/pages/chat.html and enjoy the show
To access Kiali first install a virtual service
kubectl apply -f /Users/boris/Projects/samples-java-chat/deploy/kialiVirtualService.yaml
You should see something like this:
