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README.md |
README.md
Redis and Dapr
Dapr can use Redis in two ways:
- For state persistence and restoration
- 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.
Option 1: 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.
-
Install Redis into your cluster:
helm repo add bitnami https://charts.bitnami.com/bitnami helm install redis bitnami/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.
-
Run
kubectl get pods
to see the Redis containers now running in your cluster. -
Add
redis-master:6379
as theredisHost
in your redis.yaml file. For example:metadata: - name: redisHost value: redis-master:6379
-
Next, we'll get our Redis password, which is slightly different depending on the OS we're using:
- Windows: Run below commands
# Create a file with your encoded password. kubectl get secret --namespace default redis -o jsonpath="{.data.redis-password}" > encoded.b64 # put your redis password in a text file called `password.txt`. certutil -decode encoded.b64 password.txt # Copy the password and delete the two files.
- Windows: If you are using Powershell, it would be even easier.
PS C:\> $base64pwd=kubectl get secret --namespace default redis -o jsonpath="{.data.redis-password}" PS C:\> $redispassword=[System.Text.Encoding]::UTF8.GetString([System.Convert]::FromBase64String($base64pwd)) PS C:\> $base64pwd="" PS C:\> $redispassword
- 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
Option 2: Creating an Azure Cache for Redis service
Note: This approach requires having an Azure Subscription.
-
Open the Azure Portal to start the Azure Redis Cache creation flow. Log in if necessary.
-
Fill out the necessary information
-
Click "Create" to kickoff deployment of your Redis instance.
-
Once your instance is created, you'll need to grab your access key. Navigate to "Access Keys" under "Settings" and copy your key.
-
We need the hostname of your Redis instance, which we can retrieve from the "Overview" in Azure. It should look like
xxxxxx.redis.cache.windows.net:6380
. -
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 providedredis.yaml
. If you're creating a project from the ground up, you'll create aredis.yaml
file as specified in Configuration.As the connection to Azure is encrypted, make sure to add the following block to the
metadata
section of yourredis.yaml
file.metadata: - name: enableTLS value: "true"
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 options to create a Redis Database
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
namespace: default
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
namespace: default
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
Self Hosted Mode
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 components
dir containing the YAML file and provide the path to the dapr run
command with the flag --components-path
.
If you initialized Dapr using dapr init --slim
, the Dapr CLI did not create a Redis instance or a default configuration file for it. Follow these instructions to create a Redis store. Create the redis.yaml
following the configuration instructions in a components
dir and provide the path to the dapr run
command with the flag --components-path
.