configure-redis

Redis and Dapr

Dapr can use Redis in two ways:

1. For state persistence and restoration
2. For enabling pub/sub async style message delivery

Creating a Redis Store

Dapr can use any Redis instance - containerized, running on your local dev machine, or a managed cloud service. If you already have a Redis store, move on to the Configuration section.

Creating a Redis Cache in your Kubernetes Cluster using Helm

We can use Helm to quickly create a Redis instance in our Kubernetes cluster. This approach requires Installing Helm v3.

1. Install Redis into your cluster:

helm install redis stable/redis

Note that you need a Redis version greater than 5, which is what Dapr' pub/sub functionality requires. If you're intending on using Redis as just a state store (and not for pub/sub), also a lower version can be used.

2. Run kubectl get pods to see the Redis containers now running in your cluster.

3. Add redis-master:6379 as the redisHost in your redis.yaml file. For example:

    metadata:
    - name: redisHost
      value: redis-master:6379

4. Next, we'll get our Redis password, which is slightly different depending on the OS we're using:

• Windows: Run kubectl get secret --namespace default redis -o jsonpath="{.data.redis-password}" > encoded.b64, which will create a file with your encoded password. Next, run certutil -decode encoded.b64 password.txt, which will put your redis password in a text file called password.txt. Copy the password and delete the two files.

• Linux/MacOS: Run kubectl get secret --namespace default redis -o jsonpath="{.data.redis-password}" | base64 --decode and copy the outputted password.

  Add this password as the redisPassword value in your redis.yaml file. For example:

      metadata:
      - name: redisPassword
        value: lhDOkwTlp0

Creating an Azure Managed Redis Cache

Note: this approach requires having an Azure Subscription.

1. Open this link to start the Azure Redis Cache creation flow. Log in if necessary.
2. Fill out necessary information and check the "Unblock port 6379" box, which will allow us to persist state without SSL.
3. Click "Create" to kickoff deployment of your Redis instance.
4. Once your instance is created, you'll need to grab your access key. Navigate to "Access Keys" under "Settings" and copy your key.
5. Run kubectl get svc and copy the cluster IP of your redis-master.
6. Finally, we need to add our key and our host to a redis.yaml file that Dapr can apply to our cluster. If you're running a sample, you'll add the host and key to the provided redis.yaml. If you're creating a project from the ground up, you'll create a redis.yaml file as specified in Configuration. Set the redisHost key to [IP FROM PREVIOUS STEP]:6379 and the redisPassword key to the key you copied in step 4. Note: In a production-grade application, follow secret management instructions to securely manage your secrets.

NOTE: Dapr pub/sub uses Redis Streams that was introduced by Redis 5.0, which isn't currently available on Azure Managed Redis Cache. Consequently, you can use Azure Managed Redis Cache only for state persistence.

Other ways to Create a Redis Database

• AWS Redis
• GCP Cloud MemoryStore

Configuration

Dapr can use Redis as a statestore component (for state persistence and retrieval) or as a messagebus component (for pub/sub). The following yaml files demonstrates how to define each. Note: yaml files below illustrate secret management in plain text. In a production-grade application, follow secret management instructions to securely manage your secrets.

Configuring Redis for State Persistence and Retrieval

Create a file called redis-state.yaml, and paste the following:

apiVersion: dapr.io/v1alpha1
kind: Component
metadata:
  name: statestore
spec:
  type: state.redis
  metadata:
  - name: redisHost
    value: <HOST>
  - name: redisPassword
    value: <PASSWORD>

Configuring Redis for Pub/Sub

Create a file called redis-pubsub.yaml, and paste the following:

apiVersion: dapr.io/v1alpha1
kind: Component
metadata:
  name: messagebus
spec:
  type: pubsub.redis
  metadata:
  - name: redisHost
    value: <HOST>
  - name: redisPassword
    value: <PASSWORD>

Apply the configuration

Kubernetes

kubectl apply -f redis-state.yaml

kubectl apply -f redis-pubsub.yaml

Standalone

By default the Dapr CLI creates a local Redis instance when you run dapr init. However, if you want to configure a different Redis instance, create a directory named components in the root path of your Dapr binary and then copy your redis.yaml into that directory.