How-To: Manage configuration from a store

Learn how to get application configuration and subscribe for changes

This example uses the Redis configuration store component to demonstrate how to retrieve a configuration item.

Diagram showing get configuration of example service

Note

If you haven’t already, try out the configuration quickstart for a quick walk-through on how to use the configuration API.

Create a configuration item in store

Create a configuration item in a supported configuration store. This can be a simple key-value item, with any key of your choice. As mentioned earlier, this example uses the Redis configuration store component.

Run Redis with Docker

docker run --name my-redis -p 6379:6379 -d redis:6

Save an item

Using the Redis CLI, connect to the Redis instance:

redis-cli -p 6379

Save a configuration item:

MSET orderId1 "101||1" orderId2 "102||1"

Configure a Dapr configuration store

Save the following component file to the default components folder on your machine. You can use this as the Dapr component YAML:

For Kubernetes using kubectl.
When running with the Dapr CLI.

Note

Since the Redis configuration component has identical metadata to the Redis statestore.yaml component, you can simply copy/change the Redis state store component type if you already have a Redis statestore.yaml.

apiVersion: dapr.io/v1alpha1
kind: Component
metadata:
  name: configstore
spec:
  type: configuration.redis
  metadata:
  - name: redisHost
    value: localhost:6379
  - name: redisPassword
    value: <PASSWORD>

Retrieve Configuration Items

Get configuration items

The following example shows how to get a saved configuration item using the Dapr Configuration API.

using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using Dapr.Client;

const string CONFIG_STORE_NAME = "configstore";

var builder = WebApplication.CreateBuilder(args);
builder.Services.AddDaprClient();
var app = builder.Build();

using var client = app.Services.GetRequiredServices<DaprClient>();

var configuration = await client.GetConfiguration(CONFIG_STORE_NAME, [ "orderId1", "orderId2" ]);
Console.WriteLine($"Got key=\n{configuration[0].Key} -> {configuration[0].Value}\n{configuration[1].Key} -> {configuration[1].Value}");

//dependencies
import io.dapr.client.DaprClientBuilder;
import io.dapr.client.DaprClient;
import io.dapr.client.domain.ConfigurationItem;
import io.dapr.client.domain.GetConfigurationRequest;
import io.dapr.client.domain.SubscribeConfigurationRequest;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;

//code
private static final String CONFIG_STORE_NAME = "configstore";

public static void main(String[] args) throws Exception {
    try (DaprClient client = (new DaprClientBuilder()).build()) {
      List<String> keys = new ArrayList<>();
      keys.add("orderId1");
      keys.add("orderId2");
      GetConfigurationRequest req = new GetConfigurationRequest(CONFIG_STORE_NAME, keys);
      try {
        Mono<List<ConfigurationItem>> items = client.getConfiguration(req);
        items.block().forEach(ConfigurationClient::print);
      } catch (Exception ex) {
        System.out.println(ex.getMessage());
      }
    }
}

#dependencies
from dapr.clients import DaprClient
#code
with DaprClient() as d:
        CONFIG_STORE_NAME = 'configstore'
        keys = ['orderId1', 'orderId2']
        #Startup time for dapr
        d.wait(20)
        configuration = d.get_configuration(store_name=CONFIG_STORE_NAME, keys=[keys], config_metadata={})
        print(f"Got key={configuration.items[0].key} value={configuration.items[0].value} version={configuration.items[0].version}")

package main

import (
	"context"
  "fmt"

	dapr "github.com/dapr/go-sdk/client"
)

func main() {
	ctx := context.Background()
	client, err := dapr.NewClient()
	if err != nil {
		panic(err)
	}
	items, err := client.GetConfigurationItems(ctx, "configstore", ["orderId1","orderId2"])
	if err != nil {
		panic(err)
	}
  for key, item := range items {
    fmt.Printf("get config: key = %s value = %s version = %s",key,(*item).Value, (*item).Version)
  }
}

import { CommunicationProtocolEnum, DaprClient } from "@dapr/dapr";

// JS SDK does not support Configuration API over HTTP protocol yet
const protocol = CommunicationProtocolEnum.GRPC;
const host = process.env.DAPR_HOST ?? "localhost";
const port = process.env.DAPR_GRPC_PORT ?? 3500;

const DAPR_CONFIGURATION_STORE = "configstore";
const CONFIGURATION_ITEMS = ["orderId1", "orderId2"];

async function main() {
  const client = new DaprClient(host, port, protocol);
  // Get config items from the config store
  try {
    const config = await client.configuration.get(DAPR_CONFIGURATION_STORE, CONFIGURATION_ITEMS);
    Object.keys(config.items).forEach((key) => {
      console.log("Configuration for " + key + ":", JSON.stringify(config.items[key]));
    });
  } catch (error) {
    console.log("Could not get config item, err:" + error);
    process.exit(1);
  }
}

main().catch((e) => console.error(e));

Launch a dapr sidecar:

dapr run --app-id orderprocessing --dapr-http-port 3601

In a separate terminal, get the configuration item saved earlier:

curl http://localhost:3601/v1.0/configuration/configstore?key=orderId1

Launch a Dapr sidecar:

dapr run --app-id orderprocessing --dapr-http-port 3601

In a separate terminal, get the configuration item saved earlier:

Invoke-RestMethod -Uri 'http://localhost:3601/v1.0/configuration/configstore?key=orderId1'

Below are code examples that leverage SDKs to subscribe to keys [orderId1, orderId2] using configstore store component.

using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using Dapr.Client;
using System.Text.Json;

const string DAPR_CONFIGURATION_STORE = "configstore";
var CONFIGURATION_ITEMS = new List<string> { "orderId1", "orderId2" };

var builder = WebApplication.CreateBuilder(args);
builder.Services.AddDaprClient();
var app = builder.Build();

var client = app.Services.GetRequiredService<DaprClient>();

// Subscribe for configuration changes
var subscribe = await client.SubscribeConfiguration(DAPR_CONFIGURATION_STORE, CONFIGURATION_ITEMS);

// Print configuration changes
await foreach (var items in subscribe.Source)
{
  // First invocation when app subscribes to config changes only returns subscription id
  if (items.Keys.Count == 0)
  {
    Console.WriteLine("App subscribed to config changes with subscription id: " + subscribe.Id);
    subscriptionId = subscribe.Id;
    continue;
  }
  var cfg = JsonSerializer.Serialize(items);
  Console.WriteLine("Configuration update " + cfg);
}