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

This installs a single NATS server into the default namespace. To interact with NATS, find the service with: kubectl get svc my-nats.

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 June 23, 2022: Merge pull request #2550 from ItalyPaleAle/cosmosdb-harcoded-dapr-version (cf03237)