JetStream

Detailed documentation on the NATS JetStream component

Component format

To setup JetStream pubsub create a component of type pubsub.jetstream. See this guide on how to create and apply a pubsub configuration.

  1. apiVersion: dapr.io/v1alpha1
  2. kind: Component
  3. metadata:
  4.   name: jetstream-pubsub
  5. spec:
  6.   type: pubsub.jetstream
  7.   version: v1
  8.   metadata:
  9.   - name: natsURL
  10.     value: "nats://localhost:4222"
  11.   - name: jwt
  12.     value: "eyJhbGciOiJ...6yJV_adQssw5c" # Optional. Used for decentralized JWT authentication
  13.   - name: seedKey
  14.     value: "SUACS34K232O...5Z3POU7BNIL4Y" # Optional. Used for decentralized JWT authentication
  15.   - name: name
  16.     value: "connection name"
  17.   - name: durableName
  18.     value: "consumer durable name"
  19.   - name: queueGroupName
  20.     value: "queue group name"
  21.   - name: startSequence
  22.     value: 1
  23.   - name: startTime # in Unix format
  24.     value: 1630349391
  25.   - name: deliverAll
  26.     value: false
  27.   - name: flowControl
  28.     value: false

Spec metadata fields

FieldRequiredDetailsExample
natsURLYNATS server address URL“nats://localhost:4222”
jwtNNATS decentralized authentication JWT“eyJhbGciOiJ…6yJV_adQssw5c”
seedKeyNNATS decentralized authentication seed key“SUACS34K232O…5Z3POU7BNIL4Y”
nameNNATS connection name“my-conn-name”
durableNameNDurable name“my-durable”
queueGroupNameNQueue group name“my-queue”
startSequenceNStart Sequence1
startTimeNStart Time in Unix format1630349391
deliverAllNSet deliver all as Replay Policytrue
flowControlNFlow Controltrue

Create a NATS server

You can run a NATS Server with JetStream enabled locally using Docker:

  1. docker run -d -p 4222:4222 nats:latest -js

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

Install NATS JetStream on Kubernetes by using the helm:

  1. helm repo add nats https://nats-io.github.io/k8s/helm/charts/
  2. helm install --set nats.jetstream.enabled=true my-nats nats/nats

This installs a single NATS server into the default namespace. To interact with NATS, find the service with:

  1. kubectl get svc my-nats

For more information on helm chart settings, see the Helm chart documentation.

Create JetStream

It is essential to create a NATS JetStream for a specific subject. For example, for a NATS server running locally use:

  1. nats -s localhost:4222 stream add myStream --subjects mySubject

Last modified July 27, 2022: Remove namespace element from component examples (#2647) (ff9de5c8)