NATS streaming

Detailed documentation on the NATS pubsub component

Setup NATS

You can run a NATS server locally using Docker:

  1. docker run -d -name nats-streaming -p 4222:4222 -p 8222:8222 nats-streaming

You can then interact with the server using the client port: localhost:4222.

Install NATS on Kubernetes by using the kubectl:

  1. # Single server NATS
  3. kubectl apply -f https://raw.githubusercontent.com/nats-io/k8s/master/nats-server/single-server-nats.yml
  5. kubectl apply -f https://raw.githubusercontent.com/nats-io/k8s/master/nats-streaming-server/single-server-stan.yml

This will install a single NATS-Streaming and Nats into the default namespace. To interact with NATS, find the service with: kubectl get svc stan.

For example, if installing using the example above, the NATS Streaming address would be:

<YOUR-HOST>:4222

Create a Dapr component

The next step is to create a Dapr component for NATS-Streaming.

Create the following YAML file named nats-stan.yaml:

  1. apiVersion: dapr.io/v1alpha1
  2. kind: Component
  3. metadata:
  4.   name: <NAME>
  5.   namespace: <NAMESPACE>
  6. spec:
  7.   type: pubsub.natsstreaming
  8.   version: v1
  9.   metadata:
  10.   - name: natsURL
  11.     value: <REPLACE-WITH-NATS-SERVER-ADDRESS> # Required. example nats://localhost:4222
  12.   - name: natsStreamingClusterID
  13.     value: <REPLACE-WITH-NATS-CLUSTERID> # Required.
  14.     # blow are subscription configuration.
  15.   - name: subscriptionType
  16.     value: <REPLACE-WITH-SUBSCRIPTION-TYPE> # Required. Allowed values: topic, queue.
  17.   - name: deliverNew
  18.     value: true
  19.   # - name: ackWaitTime
  20.     # value: "" # Optional. See: https://docs.nats.io/developing-with-nats-streaming/acks#acknowledgements
  21.   # - name: maxInFlight
  22.     # value: "" # Optional. See: https://docs.nats.io/developing-with-nats-streaming/acks#acknowledgements
  23.   # - name: durableSubscriptionName
  24.   #   value: ""
  25.   # following subscription options - only one can be used
  26.   # - name: startAtSequence
  27.     # value: 1
  28.   # - name: startWithLastReceived
  29.     # value: false
  30.   # - name: deliverAll
  31.   #   value: false
  32.   # - name: startAtTimeDelta
  33.   #   value: ""
  34.   # - name: startAtTime
  35.   #   value: ""
  36.   # - name: startAtTimeFormat
  37.   #   value: ""

Warning

The above example uses secrets as plain strings. It is recommended to use a secret store for the secrets as described here.

Apply the configuration

Visit this guide for instructions on configuring pub/sub components.

Related links

Last modified February 16, 2021: Merge pull request #1235 from dapr/update-v0.11 (b4e9fbb)