To try NATS with the minimal number of components, you can start with the following:
# Single server NATSkubectl apply -f https://raw.githubusercontent.com/nats-io/k8s/master/nats-server/single-server-nats.ymlkubectl apply -f https://raw.githubusercontent.com/nats-io/k8s/master/nats-streaming-server/single-server-stan.yml
This will setup:
A statefulset with a single NATS server (no auth nor TLS)
A single NATS Streaming node using file store with persistence
nats headless service to which you can connect
A NATS Streaming Server that uses the cluster name
Note that the only service your applications have to connect to is the
nats service, the NATS Streaming server will be available by using NATS as a transport.
Next, try using
nats-box to connect to the
nats service to confirm that you have set both NATS and NATS Streaming correctly.
kubectl run -i --rm --tty nats-box --image=synadia/nats-box --restart=Never# Send message to NATSnats-box:~# nats-sub -s nats hello &Listening on [hello]nats-box:~# nats-pub -s nats hello world# Send/Receive message to STANnats-box:~# stan-pub -s nats -c stan hello worldPublished [hello] : 'world'nats-box:~# stan-sub -s nats -c stan helloConnected to nats clusterID: [stan] clientID: [stan-sub]Listening on [hello], clientID=[stan-sub], qgroup= durable=[#1] Received: sequence:1 subject:"hello" data:"world" timestamp:1579544643374163630
In order to have higher availability you can setup NATS and NATS Streaming (STAN) to run in clustering mode. The following commands will setup a 3 node NATS cluster as well as a 3 node NATS Streaming cluster that has an attached volume for persistence. Note, you will need more than one node available in your Kubernetes cluster in order for this to work, so in case of deploying onto minikube or docker desktop, please try the single node installer instead.
# Create NATS clusterkubectl apply -f https://raw.githubusercontent.com/nats-io/k8s/master/nats-server/simple-nats.yml# Create STAN clusterkubectl apply -f https://raw.githubusercontent.com/nats-io/k8s/master/nats-streaming-server/simple-stan.yml
For NATS Streaming, it is actually recommended to use the Fault Tolerance mode as that would show better performance than clustering mode and better failover. You can follow this guide to setup NATS Streaming with Fault Tolerance.