The documentation you are viewing is for Dapr v1.13 which is an older version of Dapr. For up-to-date documentation, see the latest version.
Quickstart: Service Invocation
With Dapr’s Service Invocation building block, your application can communicate reliably and securely with other applications.
![Diagram showing the steps of service invocation](/images/serviceinvocation-quickstart/service-invocation-overview.png)
Dapr offers several methods for service invocation, which you can choose depending on your scenario. For this Quickstart, you’ll enable the checkout service to invoke a method using HTTP proxy in the order-processor service and by either:
- Running all applications in this sample simultaneously with the Multi-App Run template file, or
- Running one application at a time
Learn more about Dapr’s methods for service invocation in the overview article.
Run using Multi-App Run
Select your preferred language before proceeding with the Quickstart.
Step 1: Pre-requisites
For this example, you will need:
Step 2: Set up the environment
Clone the sample provided in the Quickstarts repo.
git clone https://github.com/dapr/quickstarts.git
From the root of the Quickstart clone directory, navigate to the quickstart directory.
cd service_invocation/python/http
Install the dependencies for the order-processor
and checkout
apps:
cd ./order-processor
pip3 install -r requirements.txt
cd ../checkout
pip3 install -r requirements.txt
cd ..
Step 3: Run the order-processor
and checkout
services
With the following command, simultaneously run the following services alongside their own Dapr sidecars:
- The
order-processor
service - The
checkout
service
dapr run -f .
Note: Since Python3.exe is not defined in Windows, you may need to change
python3
topython
in thedapr.yaml
file before runningdapr run -f .
Expected output
== APP - order-processor == Order received : Order { orderId = 1 }
== APP - checkout == Order passed: Order { OrderId = 1 }
== APP - order-processor == Order received : Order { orderId = 2 }
== APP - checkout == Order passed: Order { OrderId = 2 }
== APP - order-processor == Order received : Order { orderId = 3 }
== APP - checkout == Order passed: Order { OrderId = 3 }
== APP - order-processor == Order received : Order { orderId = 4 }
== APP - checkout == Order passed: Order { OrderId = 4 }
== APP - order-processor == Order received : Order { orderId = 5 }
== APP - checkout == Order passed: Order { OrderId = 5 }
== APP - order-processor == Order received : Order { orderId = 6 }
== APP - checkout == Order passed: Order { OrderId = 6 }
== APP - order-processor == Order received : Order { orderId = 7 }
== APP - checkout == Order passed: Order { OrderId = 7 }
== APP - order-processor == Order received : Order { orderId = 8 }
== APP - checkout == Order passed: Order { OrderId = 8 }
== APP - order-processor == Order received : Order { orderId = 9 }
== APP - checkout == Order passed: Order { OrderId = 9 }
== APP - order-processor == Order received : Order { orderId = 10 }
== APP - checkout == Order passed: Order { OrderId = 10 }
== APP - order-processor == Order received : Order { orderId = 11 }
== APP - checkout == Order passed: Order { OrderId = 11 }
== APP - order-processor == Order received : Order { orderId = 12 }
== APP - checkout == Order passed: Order { OrderId = 12 }
== APP - order-processor == Order received : Order { orderId = 13 }
== APP - checkout == Order passed: Order { OrderId = 13 }
== APP - order-processor == Order received : Order { orderId = 14 }
== APP - checkout == Order passed: Order { OrderId = 14 }
== APP - order-processor == Order received : Order { orderId = 15 }
== APP - checkout == Order passed: Order { OrderId = 15 }
== APP - order-processor == Order received : Order { orderId = 16 }
== APP - checkout == Order passed: Order { OrderId = 16 }
== APP - order-processor == Order received : Order { orderId = 17 }
== APP - checkout == Order passed: Order { OrderId = 17 }
== APP - order-processor == Order received : Order { orderId = 18 }
== APP - checkout == Order passed: Order { OrderId = 18 }
== APP - order-processor == Order received : Order { orderId = 19 }
== APP - checkout == Order passed: Order { OrderId = 19 }
== APP - order-processor == Order received : Order { orderId = 20 }
== APP - checkout == Order passed: Order { OrderId = 20 }
Exited App successfully
What happened?
Running dapr run -f .
in this Quickstart started both the subscriber and publisher applications using the dapr.yaml
Multi-App Run template file.
dapr.yaml
Multi-App Run template file
Running the Multi-App Run template file with dapr run -f .
starts all applications in your project. In this Quickstart, the dapr.yaml
file contains the following:
version: 1
apps:
- appDirPath: ./order-processor/
appID: order-processor
appPort: 8001
command: ["python3", "app.py"]
- appID: checkout
appDirPath: ./checkout/
command: ["python3", "app.py"]
order-processor
service
The order-processor
service receives the call from the checkout
service:
@app.route('/orders', methods=['POST'])
def getOrder():
data = request.json
print('Order received : ' + json.dumps(data), flush=True)
return json.dumps({'success': True}), 200, {
'ContentType': 'application/json'}
app.run(port=8001)
checkout
service
In the checkout
service, you’ll notice there’s no need to rewrite your app code to use Dapr’s service invocation. You can enable service invocation by simply adding the dapr-app-id
header, which specifies the ID of the target service.
headers = {'dapr-app-id': 'order-processor'}
result = requests.post(
url='%s/orders' % (base_url),
data=json.dumps(order),
headers=headers
)
Step 1: Pre-requisites
For this example, you will need:
Step 2: Set up the environment
Clone the sample provided in the Quickstarts repo.
git clone https://github.com/dapr/quickstarts.git
From the root of the Quickstart clone directory, navigate to the quickstart directory.
cd service_invocation/javascript/http
Install the dependencies for the order-processor
and checkout
apps:
cd ./order-processor
npm install
cd ../checkout
npm install
cd ..
Step 3: Run the order-processor
and checkout
services
With the following command, simultaneously run the following services alongside their own Dapr sidecars:
- The
order-processor
service - The
checkout
service
dapr run -f .
Expected output
== APP - order-processor == Order received : Order { orderId = 1 }
== APP - checkout == Order passed: Order { OrderId = 1 }
== APP - order-processor == Order received : Order { orderId = 2 }
== APP - checkout == Order passed: Order { OrderId = 2 }
== APP - order-processor == Order received : Order { orderId = 3 }
== APP - checkout == Order passed: Order { OrderId = 3 }
== APP - order-processor == Order received : Order { orderId = 4 }
== APP - checkout == Order passed: Order { OrderId = 4 }
== APP - order-processor == Order received : Order { orderId = 5 }
== APP - checkout == Order passed: Order { OrderId = 5 }
== APP - order-processor == Order received : Order { orderId = 6 }
== APP - checkout == Order passed: Order { OrderId = 6 }
== APP - order-processor == Order received : Order { orderId = 7 }
== APP - checkout == Order passed: Order { OrderId = 7 }
== APP - order-processor == Order received : Order { orderId = 8 }
== APP - checkout == Order passed: Order { OrderId = 8 }
== APP - order-processor == Order received : Order { orderId = 9 }
== APP - checkout == Order passed: Order { OrderId = 9 }
== APP - order-processor == Order received : Order { orderId = 10 }
== APP - checkout == Order passed: Order { OrderId = 10 }
== APP - order-processor == Order received : Order { orderId = 11 }
== APP - checkout == Order passed: Order { OrderId = 11 }
== APP - order-processor == Order received : Order { orderId = 12 }
== APP - checkout == Order passed: Order { OrderId = 12 }
== APP - order-processor == Order received : Order { orderId = 13 }
== APP - checkout == Order passed: Order { OrderId = 13 }
== APP - order-processor == Order received : Order { orderId = 14 }
== APP - checkout == Order passed: Order { OrderId = 14 }
== APP - order-processor == Order received : Order { orderId = 15 }
== APP - checkout == Order passed: Order { OrderId = 15 }
== APP - order-processor == Order received : Order { orderId = 16 }
== APP - checkout == Order passed: Order { OrderId = 16 }
== APP - order-processor == Order received : Order { orderId = 17 }
== APP - checkout == Order passed: Order { OrderId = 17 }
== APP - order-processor == Order received : Order { orderId = 18 }
== APP - checkout == Order passed: Order { OrderId = 18 }
== APP - order-processor == Order received : Order { orderId = 19 }
== APP - checkout == Order passed: Order { OrderId = 19 }
== APP - order-processor == Order received : Order { orderId = 20 }
== APP - checkout == Order passed: Order { OrderId = 20 }
Exited App successfully
What happened?
Running dapr run -f .
in this Quickstart started both the subscriber and publisher applications using the dapr.yaml
Multi-App Run template file.
dapr.yaml
Multi-App Run template file
Running the Multi-App Run template file with dapr run -f .
starts all applications in your project. In this Quickstart, the dapr.yaml
file contains the following:
version: 1
apps:
- appDirPath: ./order-processor/
appID: order-processor
appPort: 5001
command: ["npm", "start"]
- appID: checkout
appDirPath: ./checkout/
command: ["npm", "start"]
order-processor
service
The order-processor
service receives the call from the checkout
service:
app.post('/orders', (req, res) => {
console.log("Order received:", req.body);
res.sendStatus(200);
});
checkout
service
In the checkout
service, you’ll notice there’s no need to rewrite your app code to use Dapr’s service invocation. You can enable service invocation by simply adding the dapr-app-id
header, which specifies the ID of the target service.
let axiosConfig = {
headers: {
"dapr-app-id": "order-processor"
}
};
const res = await axios.post(`${DAPR_HOST}:${DAPR_HTTP_PORT}/orders`, order , axiosConfig);
console.log("Order passed: " + res.config.data);
Step 1: Pre-requisites
For this example, you will need:
Step 2: Set up the environment
Clone the sample provided in the Quickstarts repo.
git clone https://github.com/dapr/quickstarts.git
From the root of the Quickstart clone directory, navigate to the quickstart directory.
cd service_invocation/csharp/http
Install the dependencies for the order-processor
and checkout
apps:
cd ./order-processor
dotnet restore
dotnet build
cd ../checkout
dotnet restore
dotnet build
cd ..
Step 3: Run the order-processor
and checkout
services
With the following command, simultaneously run the following services alongside their own Dapr sidecars:
- The
order-processor
service - The
checkout
service
dapr run -f .
Expected output
== APP - order-processor == Order received : Order { orderId = 1 }
== APP - checkout == Order passed: Order { OrderId = 1 }
== APP - order-processor == Order received : Order { orderId = 2 }
== APP - checkout == Order passed: Order { OrderId = 2 }
== APP - order-processor == Order received : Order { orderId = 3 }
== APP - checkout == Order passed: Order { OrderId = 3 }
== APP - order-processor == Order received : Order { orderId = 4 }
== APP - checkout == Order passed: Order { OrderId = 4 }
== APP - order-processor == Order received : Order { orderId = 5 }
== APP - checkout == Order passed: Order { OrderId = 5 }
== APP - order-processor == Order received : Order { orderId = 6 }
== APP - checkout == Order passed: Order { OrderId = 6 }
== APP - order-processor == Order received : Order { orderId = 7 }
== APP - checkout == Order passed: Order { OrderId = 7 }
== APP - order-processor == Order received : Order { orderId = 8 }
== APP - checkout == Order passed: Order { OrderId = 8 }
== APP - order-processor == Order received : Order { orderId = 9 }
== APP - checkout == Order passed: Order { OrderId = 9 }
== APP - order-processor == Order received : Order { orderId = 10 }
== APP - checkout == Order passed: Order { OrderId = 10 }
== APP - order-processor == Order received : Order { orderId = 11 }
== APP - checkout == Order passed: Order { OrderId = 11 }
== APP - order-processor == Order received : Order { orderId = 12 }
== APP - checkout == Order passed: Order { OrderId = 12 }
== APP - order-processor == Order received : Order { orderId = 13 }
== APP - checkout == Order passed: Order { OrderId = 13 }
== APP - order-processor == Order received : Order { orderId = 14 }
== APP - checkout == Order passed: Order { OrderId = 14 }
== APP - order-processor == Order received : Order { orderId = 15 }
== APP - checkout == Order passed: Order { OrderId = 15 }
== APP - order-processor == Order received : Order { orderId = 16 }
== APP - checkout == Order passed: Order { OrderId = 16 }
== APP - order-processor == Order received : Order { orderId = 17 }
== APP - checkout == Order passed: Order { OrderId = 17 }
== APP - order-processor == Order received : Order { orderId = 18 }
== APP - checkout == Order passed: Order { OrderId = 18 }
== APP - order-processor == Order received : Order { orderId = 19 }
== APP - checkout == Order passed: Order { OrderId = 19 }
== APP - order-processor == Order received : Order { orderId = 20 }
== APP - checkout == Order passed: Order { OrderId = 20 }
Exited App successfully
What happened?
Running dapr run -f .
in this Quickstart started both the subscriber and publisher applications using the dapr.yaml
Multi-App Run template file.
dapr.yaml
Multi-App Run template file
Running the Multi-App Run template file with dapr run -f .
starts all applications in your project. In this Quickstart, the dapr.yaml
file contains the following:
version: 1
apps:
- appDirPath: ./order-processor/
appID: order-processor
appPort: 7001
command: ["dotnet", "run"]
- appID: checkout
appDirPath: ./checkout/
command: ["dotnet", "run"]
order-processor
service
The order-processor
service receives the call from the checkout
service:
app.MapPost("/orders", (Order order) =>
{
Console.WriteLine("Order received : " + order);
return order.ToString();
});
checkout
service
In the Program.cs file for the checkout
service, you’ll notice there’s no need to rewrite your app code to use Dapr’s service invocation. You can enable service invocation by simply adding the dapr-app-id
header, which specifies the ID of the target service.
var client = new HttpClient();
client.DefaultRequestHeaders.Accept.Add(new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue("application/json"));
client.DefaultRequestHeaders.Add("dapr-app-id", "order-processor");
var response = await client.PostAsync($"{baseURL}/orders", content);
Console.WriteLine("Order passed: " + order);
Step 1: Pre-requisites
For this example, you will need:
- Dapr CLI and initialized environment.
- Java JDK 17 (or greater):
- Oracle JDK, or
- OpenJDK
- Apache Maven, version 3.x.
Step 2: Set up the environment
Clone the sample provided in the Quickstarts repo.
git clone https://github.com/dapr/quickstarts.git
From the root of the Quickstart clone directory, navigate to the quickstart directory.
cd service_invocation/java/http
Install the dependencies for the order-processor
and checkout
apps:
cd ./order-processor
mvn clean install
cd ../checkout
mvn clean install
cd ..
Step 3: Run the order-processor
and checkout
services
With the following command, simultaneously run the following services alongside their own Dapr sidecars:
- The
order-processor
service - The
checkout
service
dapr run -f .
Expected output
== APP - order-processor == Order received : Order { orderId = 1 }
== APP - checkout == Order passed: Order { OrderId = 1 }
== APP - order-processor == Order received : Order { orderId = 2 }
== APP - checkout == Order passed: Order { OrderId = 2 }
== APP - order-processor == Order received : Order { orderId = 3 }
== APP - checkout == Order passed: Order { OrderId = 3 }
== APP - order-processor == Order received : Order { orderId = 4 }
== APP - checkout == Order passed: Order { OrderId = 4 }
== APP - order-processor == Order received : Order { orderId = 5 }
== APP - checkout == Order passed: Order { OrderId = 5 }
== APP - order-processor == Order received : Order { orderId = 6 }
== APP - checkout == Order passed: Order { OrderId = 6 }
== APP - order-processor == Order received : Order { orderId = 7 }
== APP - checkout == Order passed: Order { OrderId = 7 }
== APP - order-processor == Order received : Order { orderId = 8 }
== APP - checkout == Order passed: Order { OrderId = 8 }
== APP - order-processor == Order received : Order { orderId = 9 }
== APP - checkout == Order passed: Order { OrderId = 9 }
== APP - order-processor == Order received : Order { orderId = 10 }
== APP - checkout == Order passed: Order { OrderId = 10 }
== APP - order-processor == Order received : Order { orderId = 11 }
== APP - checkout == Order passed: Order { OrderId = 11 }
== APP - order-processor == Order received : Order { orderId = 12 }
== APP - checkout == Order passed: Order { OrderId = 12 }
== APP - order-processor == Order received : Order { orderId = 13 }
== APP - checkout == Order passed: Order { OrderId = 13 }
== APP - order-processor == Order received : Order { orderId = 14 }
== APP - checkout == Order passed: Order { OrderId = 14 }
== APP - order-processor == Order received : Order { orderId = 15 }
== APP - checkout == Order passed: Order { OrderId = 15 }
== APP - order-processor == Order received : Order { orderId = 16 }
== APP - checkout == Order passed: Order { OrderId = 16 }
== APP - order-processor == Order received : Order { orderId = 17 }
== APP - checkout == Order passed: Order { OrderId = 17 }
== APP - order-processor == Order received : Order { orderId = 18 }
== APP - checkout == Order passed: Order { OrderId = 18 }
== APP - order-processor == Order received : Order { orderId = 19 }
== APP - checkout == Order passed: Order { OrderId = 19 }
== APP - order-processor == Order received : Order { orderId = 20 }
== APP - checkout == Order passed: Order { OrderId = 20 }
Exited App successfully
What happened?
Running dapr run -f .
in this Quickstart started both the subscriber and publisher applications using the dapr.yaml
Multi-App Run template file.
dapr.yaml
Multi-App Run template file
Running the Multi-App Run template file with dapr run -f .
starts all applications in your project. In this Quickstart, the dapr.yaml
file contains the following:
version: 1
apps:
- appDirPath: ./order-processor/
appID: order-processor
appPort: 9001
command: ["java", "-jar", "target/OrderProcessingService-0.0.1-SNAPSHOT.jar"]
- appID: checkout
appDirPath: ./checkout/
command: ["java", "-jar", "target/CheckoutService-0.0.1-SNAPSHOT.jar"]
order-processor
service
The order-processor
service receives the call from the checkout
service:
public String processOrders(@RequestBody Order body) {
System.out.println("Order received: "+ body.getOrderId());
return "CID" + body.getOrderId();
}
checkout
service
In the checkout
service, you’ll notice there’s no need to rewrite your app code to use Dapr’s service invocation. You can enable service invocation by simply adding the dapr-app-id
header, which specifies the ID of the target service.
.header("Content-Type", "application/json")
.header("dapr-app-id", "order-processor")
HttpResponse<String> response = httpClient.send(request, HttpResponse.BodyHandlers.ofString());
System.out.println("Order passed: "+ orderId)
Step 1: Pre-requisites
For this example, you will need:
Step 2: Set up the environment
Clone the sample provided in the Quickstarts repo.
git clone https://github.com/dapr/quickstarts.git
From the root of the Quickstart clone directory, navigate to the quickstart directory.
cd service_invocation/go/http
Install the dependencies for the order-processor
and checkout
apps:
cd ./order-processor
go build .
cd ../checkout
go build .
cd ..
Step 3: Run the order-processor
and checkout
services
With the following command, simultaneously run the following services alongside their own Dapr sidecars:
- The
order-processor
service - The
checkout
service
dapr run -f .
Expected output
== APP - order-processor == Order received : Order { orderId = 1 }
== APP - checkout == Order passed: Order { OrderId = 1 }
== APP - order-processor == Order received : Order { orderId = 2 }
== APP - checkout == Order passed: Order { OrderId = 2 }
== APP - order-processor == Order received : Order { orderId = 3 }
== APP - checkout == Order passed: Order { OrderId = 3 }
== APP - order-processor == Order received : Order { orderId = 4 }
== APP - checkout == Order passed: Order { OrderId = 4 }
== APP - order-processor == Order received : Order { orderId = 5 }
== APP - checkout == Order passed: Order { OrderId = 5 }
== APP - order-processor == Order received : Order { orderId = 6 }
== APP - checkout == Order passed: Order { OrderId = 6 }
== APP - order-processor == Order received : Order { orderId = 7 }
== APP - checkout == Order passed: Order { OrderId = 7 }
== APP - order-processor == Order received : Order { orderId = 8 }
== APP - checkout == Order passed: Order { OrderId = 8 }
== APP - order-processor == Order received : Order { orderId = 9 }
== APP - checkout == Order passed: Order { OrderId = 9 }
== APP - order-processor == Order received : Order { orderId = 10 }
== APP - checkout == Order passed: Order { OrderId = 10 }
== APP - order-processor == Order received : Order { orderId = 11 }
== APP - checkout == Order passed: Order { OrderId = 11 }
== APP - order-processor == Order received : Order { orderId = 12 }
== APP - checkout == Order passed: Order { OrderId = 12 }
== APP - order-processor == Order received : Order { orderId = 13 }
== APP - checkout == Order passed: Order { OrderId = 13 }
== APP - order-processor == Order received : Order { orderId = 14 }
== APP - checkout == Order passed: Order { OrderId = 14 }
== APP - order-processor == Order received : Order { orderId = 15 }
== APP - checkout == Order passed: Order { OrderId = 15 }
== APP - order-processor == Order received : Order { orderId = 16 }
== APP - checkout == Order passed: Order { OrderId = 16 }
== APP - order-processor == Order received : Order { orderId = 17 }
== APP - checkout == Order passed: Order { OrderId = 17 }
== APP - order-processor == Order received : Order { orderId = 18 }
== APP - checkout == Order passed: Order { OrderId = 18 }
== APP - order-processor == Order received : Order { orderId = 19 }
== APP - checkout == Order passed: Order { OrderId = 19 }
== APP - order-processor == Order received : Order { orderId = 20 }
== APP - checkout == Order passed: Order { OrderId = 20 }
Exited App successfully
What happened?
Running dapr run -f .
in this Quickstart started both the subscriber and publisher applications using the dapr.yaml
Multi-App Run template file.
dapr.yaml
Multi-App Run template file
Running the Multi-App Run template file with dapr run -f .
starts all applications in your project. In this Quickstart, the dapr.yaml
file contains the following:
version: 1
apps:
- appDirPath: ./order-processor/
appID: order-processor
appPort: 6006
command: ["go", "run", "."]
- appID: checkout
appDirPath: ./checkout/
command: ["go", "run", "."]
order-processor
service
In the order-processor
service, each order is received via an HTTP POST request and processed by the getOrder
function.
func getOrder(w http.ResponseWriter, r *http.Request) {
data, err := ioutil.ReadAll(r.Body)
if err != nil {
log.Fatal(err)
}
log.Printf("Order received : %s", string(data))
}
checkout
service
In the checkout
service, you’ll notice there’s no need to rewrite your app code to use Dapr’s service invocation. You can enable service invocation by simply adding the dapr-app-id
header, which specifies the ID of the target service.
req.Header.Add("dapr-app-id", "order-processor")
response, err := client.Do(req)
Run one application at a time
Select your preferred language before proceeding with the Quickstart.
Step 1: Pre-requisites
For this example, you will need:
Step 2: Set up the environment
Clone the sample provided in the Quickstarts repo.
git clone https://github.com/dapr/quickstarts.git
Step 3: Run order-processor
service
In a terminal window, from the root of the Quickstart clone directory
navigate to order-processor
directory.
cd service_invocation/python/http/order-processor
Install the dependencies and build the application:
pip3 install -r requirements.txt
Run the order-processor
service alongside a Dapr sidecar.
dapr run --app-port 8001 --app-id order-processor --app-protocol http --dapr-http-port 3501 -- python3 app.py
Note: Since Python3.exe is not defined in Windows, you may need to use
python app.py
instead ofpython3 app.py
.
@app.route('/orders', methods=['POST'])
def getOrder():
data = request.json
print('Order received : ' + json.dumps(data), flush=True)
return json.dumps({'success': True}), 200, {
'ContentType': 'application/json'}
app.run(port=8001)
Step 4: Run checkout
service
In a new terminal window, from the root of the Quickstart clone directory
navigate to the checkout
directory.
cd service_invocation/python/http/checkout
Install the dependencies and build the application:
pip3 install -r requirements.txt
Run the checkout
service alongside a Dapr sidecar.
dapr run --app-id checkout --app-protocol http --dapr-http-port 3500 -- python3 app.py
Note: Since Python3.exe is not defined in Windows, you may need to use
python app.py
instead ofpython3 app.py
.
In the checkout
service, you’ll notice there’s no need to rewrite your app code to use Dapr’s service invocation. You can enable service invocation by simply adding the dapr-app-id
header, which specifies the ID of the target service.
headers = {'dapr-app-id': 'order-processor'}
result = requests.post(
url='%s/orders' % (base_url),
data=json.dumps(order),
headers=headers
)
Step 5: Use with Multi-App Run
You can run the Dapr applications in this quickstart with the Multi-App Run template. Instead of running two separate dapr run
commands for the order-processor
and checkout
applications, run the following command:
dapr run -f .
To stop all applications, run:
dapr stop -f .
Step 6: View the Service Invocation outputs
Dapr invokes an application on any Dapr instance. In the code, the sidecar programming model encourages each application to talk to its own instance of Dapr. The Dapr instances then discover and communicate with one another.
checkout
service output:
== APP == Order passed: {"orderId": 1}
== APP == Order passed: {"orderId": 2}
== APP == Order passed: {"orderId": 3}
== APP == Order passed: {"orderId": 4}
== APP == Order passed: {"orderId": 5}
== APP == Order passed: {"orderId": 6}
== APP == Order passed: {"orderId": 7}
== APP == Order passed: {"orderId": 8}
== APP == Order passed: {"orderId": 9}
== APP == Order passed: {"orderId": 10}
order-processor
service output:
== APP == Order received: {"orderId": 1}
== APP == Order received: {"orderId": 2}
== APP == Order received: {"orderId": 3}
== APP == Order received: {"orderId": 4}
== APP == Order received: {"orderId": 5}
== APP == Order received: {"orderId": 6}
== APP == Order received: {"orderId": 7}
== APP == Order received: {"orderId": 8}
== APP == Order received: {"orderId": 9}
== APP == Order received: {"orderId": 10}
Step 1: Pre-requisites
For this example, you will need:
Step 2: Set up the environment
Clone the sample provided in the Quickstarts repo.
git clone https://github.com/dapr/quickstarts.git
Step 3: Run order-processor
service
In a terminal window, from the root of the Quickstart clone directory
navigate to order-processor
directory.
cd service_invocation/javascript/http/order-processor
Install the dependencies:
npm install
Run the order-processor
service alongside a Dapr sidecar.
dapr run --app-port 5001 --app-id order-processor --app-protocol http --dapr-http-port 3501 -- npm start
app.post('/orders', (req, res) => {
console.log("Order received:", req.body);
res.sendStatus(200);
});
Step 4: Run checkout
service
In a new terminal window, from the root of the Quickstart clone directory
navigate to the checkout
directory.
cd service_invocation/javascript/http/checkout
Install the dependencies:
npm install
Run the checkout
service alongside a Dapr sidecar.
dapr run --app-id checkout --app-protocol http --dapr-http-port 3500 -- npm start
In the checkout
service, you’ll notice there’s no need to rewrite your app code to use Dapr’s service invocation. You can enable service invocation by simply adding the dapr-app-id
header, which specifies the ID of the target service.
let axiosConfig = {
headers: {
"dapr-app-id": "order-processor"
}
};
const res = await axios.post(`${DAPR_HOST}:${DAPR_HTTP_PORT}/orders`, order , axiosConfig);
console.log("Order passed: " + res.config.data);
Step 5: Use with Multi-App Run
You can run the Dapr applications in this quickstart with the Multi-App Run template. Instead of running two separate dapr run
commands for the order-processor
and checkout
applications, run the following command:
dapr run -f .
To stop all applications, run:
dapr stop -f .
Step 6: View the Service Invocation outputs
Dapr invokes an application on any Dapr instance. In the code, the sidecar programming model encourages each application to talk to its own instance of Dapr. The Dapr instances then discover and communicate with one another.
checkout
service output:
== APP == Order passed: {"orderId": 1}
== APP == Order passed: {"orderId": 2}
== APP == Order passed: {"orderId": 3}
== APP == Order passed: {"orderId": 4}
== APP == Order passed: {"orderId": 5}
== APP == Order passed: {"orderId": 6}
== APP == Order passed: {"orderId": 7}
== APP == Order passed: {"orderId": 8}
== APP == Order passed: {"orderId": 9}
== APP == Order passed: {"orderId": 10}
order-processor
service output:
== APP == Order received: {"orderId": 1}
== APP == Order received: {"orderId": 2}
== APP == Order received: {"orderId": 3}
== APP == Order received: {"orderId": 4}
== APP == Order received: {"orderId": 5}
== APP == Order received: {"orderId": 6}
== APP == Order received: {"orderId": 7}
== APP == Order received: {"orderId": 8}
== APP == Order received: {"orderId": 9}
== APP == Order received: {"orderId": 10}
Step 1: Pre-requisites
For this example, you will need:
Step 2: Set up the environment
Clone the sample provided in the Quickstarts repo.
git clone https://github.com/dapr/quickstarts.git
Step 3: Run order-processor
service
In a terminal window, from the root of the Quickstart clone directory
navigate to order-processor
directory.
cd service_invocation/csharp/http/order-processor
Install the dependencies:
dotnet restore
dotnet build
Run the order-processor
service alongside a Dapr sidecar.
dapr run --app-port 7001 --app-id order-processor --app-protocol http --dapr-http-port 3501 -- dotnet run
Below is the working code block from the order processor’s Program.cs
file.
app.MapPost("/orders", (Order order) =>
{
Console.WriteLine("Order received : " + order);
return order.ToString();
});
Step 4: Run checkout
service
In a new terminal window, from the root of the Quickstart clone directory
navigate to the checkout
directory.
cd service_invocation/csharp/http/checkout
Install the dependencies:
dotnet restore
dotnet build
Run the checkout
service alongside a Dapr sidecar.
dapr run --app-id checkout --app-protocol http --dapr-http-port 3500 -- dotnet run
In the Program.cs file for the checkout
service, you’ll notice there’s no need to rewrite your app code to use Dapr’s service invocation. You can enable service invocation by simply adding the dapr-app-id
header, which specifies the ID of the target service.
var client = new HttpClient();
client.DefaultRequestHeaders.Accept.Add(new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue("application/json"));
client.DefaultRequestHeaders.Add("dapr-app-id", "order-processor");
var response = await client.PostAsync($"{baseURL}/orders", content);
Console.WriteLine("Order passed: " + order);
Step 5: Use with Multi-App Run
You can run the Dapr applications in this quickstart with the Multi-App Run template. Instead of running two separate dapr run
commands for the order-processor
and checkout
applications, run the following command:
dapr run -f .
To stop all applications, run:
dapr stop -f .
Step 6: View the Service Invocation outputs
Dapr invokes an application on any Dapr instance. In the code, the sidecar programming model encourages each application to talk to its own instance of Dapr. The Dapr instances then discover and communicate with one another.
checkout
service output:
== APP == Order passed: Order { OrderId: 1 }
== APP == Order passed: Order { OrderId: 2 }
== APP == Order passed: Order { OrderId: 3 }
== APP == Order passed: Order { OrderId: 4 }
== APP == Order passed: Order { OrderId: 5 }
== APP == Order passed: Order { OrderId: 6 }
== APP == Order passed: Order { OrderId: 7 }
== APP == Order passed: Order { OrderId: 8 }
== APP == Order passed: Order { OrderId: 9 }
== APP == Order passed: Order { OrderId: 10 }
order-processor
service output:
== APP == Order received: Order { OrderId: 1 }
== APP == Order received: Order { OrderId: 2 }
== APP == Order received: Order { OrderId: 3 }
== APP == Order received: Order { OrderId: 4 }
== APP == Order received: Order { OrderId: 5 }
== APP == Order received: Order { OrderId: 6 }
== APP == Order received: Order { OrderId: 7 }
== APP == Order received: Order { OrderId: 8 }
== APP == Order received: Order { OrderId: 9 }
== APP == Order received: Order { OrderId: 10 }
Step 1: Pre-requisites
For this example, you will need:
- Dapr CLI and initialized environment.
- Java JDK 17 (or greater):
- Oracle JDK, or
- OpenJDK
- Apache Maven, version 3.x.
Step 2: Set up the environment
Clone the sample provided in the Quickstarts repo.
git clone https://github.com/dapr/quickstarts.git
Step 3: Run order-processor
service
In a terminal window, from the root of the Quickstart clone directory
navigate to order-processor
directory.
cd service_invocation/java/http/order-processor
Install the dependencies:
mvn clean install
Run the order-processor
service alongside a Dapr sidecar.
dapr run --app-id order-processor --app-port 9001 --app-protocol http --dapr-http-port 3501 -- java -jar target/OrderProcessingService-0.0.1-SNAPSHOT.jar
public String processOrders(@RequestBody Order body) {
System.out.println("Order received: "+ body.getOrderId());
return "CID" + body.getOrderId();
}
Step 4: Run checkout
service
In a new terminal window, from the root of the Quickstart clone directory
navigate to the checkout
directory.
cd service_invocation/java/http/checkout
Install the dependencies:
mvn clean install
Run the checkout
service alongside a Dapr sidecar.
dapr run --app-id checkout --app-protocol http --dapr-http-port 3500 -- java -jar target/CheckoutService-0.0.1-SNAPSHOT.jar
In the checkout
service, you’ll notice there’s no need to rewrite your app code to use Dapr’s service invocation. You can enable service invocation by simply adding the dapr-app-id
header, which specifies the ID of the target service.
.header("Content-Type", "application/json")
.header("dapr-app-id", "order-processor")
HttpResponse<String> response = httpClient.send(request, HttpResponse.BodyHandlers.ofString());
System.out.println("Order passed: "+ orderId)
Step 5: Use with Multi-App Run
You can run the Dapr applications in this quickstart with the Multi-App Run template. Instead of running two separate dapr run
commands for the order-processor
and checkout
applications, run the following command:
dapr run -f .
To stop all applications, run:
dapr stop -f .
Step 6: View the Service Invocation outputs
Dapr invokes an application on any Dapr instance. In the code, the sidecar programming model encourages each application to talk to its own instance of Dapr. The Dapr instances then discover and communicate with one another.
checkout
service output:
== APP == Order passed: 1
== APP == Order passed: 2
== APP == Order passed: 3
== APP == Order passed: 4
== APP == Order passed: 5
== APP == Order passed: 6
== APP == Order passed: 7
== APP == Order passed: 8
== APP == Order passed: 9
== APP == Order passed: 10
order-processor
service output:
== APP == Order received: 1
== APP == Order received: 2
== APP == Order received: 3
== APP == Order received: 4
== APP == Order received: 5
== APP == Order received: 6
== APP == Order received: 7
== APP == Order received: 8
== APP == Order received: 9
== APP == Order received: 10
Step 1: Pre-requisites
For this example, you will need:
Step 2: Set up the environment
Clone the sample provided in the Quickstarts repo.
git clone https://github.com/dapr/quickstarts.git
Step 3: Run order-processor
service
In a terminal window, from the root of the Quickstart clone directory
navigate to order-processor
directory.
cd service_invocation/go/http/order-processor
Install the dependencies:
go build .
Run the order-processor
service alongside a Dapr sidecar.
dapr run --app-port 6006 --app-id order-processor --app-protocol http --dapr-http-port 3501 -- go run .
Each order is received via an HTTP POST request and processed by the
getOrder
function.
func getOrder(w http.ResponseWriter, r *http.Request) {
data, err := ioutil.ReadAll(r.Body)
if err != nil {
log.Fatal(err)
}
log.Printf("Order received : %s", string(data))
}
Step 4: Run checkout
service
In a new terminal window, from the root of the Quickstart clone directory
navigate to the checkout
directory.
cd service_invocation/go/http/checkout
Install the dependencies:
go build .
Run the checkout
service alongside a Dapr sidecar.
dapr run --app-id checkout --app-protocol http --dapr-http-port 3500 -- go run .
In the checkout
service, you’ll notice there’s no need to rewrite your app code to use Dapr’s service invocation. You can enable service invocation by simply adding the dapr-app-id
header, which specifies the ID of the target service.
req.Header.Add("dapr-app-id", "order-processor")
response, err := client.Do(req)
Step 5: Use with Multi-App Run
You can run the Dapr applications in this quickstart with the Multi-App Run template. Instead of running two separate dapr run
commands for the order-processor
and checkout
applications, run the following command:
dapr run -f .
To stop all applications, run:
dapr stop -f .
Step 6: View the Service Invocation outputs
Dapr invokes an application on any Dapr instance. In the code, the sidecar programming model encourages each application to talk to its own instance of Dapr. The Dapr instances then discover and communicate with one another.
checkout
service output:
== APP == Order passed: {"orderId":1}
== APP == Order passed: {"orderId":2}
== APP == Order passed: {"orderId":3}
== APP == Order passed: {"orderId":4}
== APP == Order passed: {"orderId":5}
== APP == Order passed: {"orderId":6}
== APP == Order passed: {"orderId":7}
== APP == Order passed: {"orderId":8}
== APP == Order passed: {"orderId":9}
== APP == Order passed: {"orderId":10}
order-processor
service output:
== APP == Order received : {"orderId":1}
== APP == Order received : {"orderId":2}
== APP == Order received : {"orderId":3}
== APP == Order received : {"orderId":4}
== APP == Order received : {"orderId":5}
== APP == Order received : {"orderId":6}
== APP == Order received : {"orderId":7}
== APP == Order received : {"orderId":8}
== APP == Order received : {"orderId":9}
== APP == Order received : {"orderId":10}
Tell us what you think!
We’re continuously working to improve our Quickstart examples and value your feedback. Did you find this Quickstart helpful? Do you have suggestions for improvement?
Join the discussion in our discord channel.
Next Steps
- Learn more about Service Invocation as a Dapr building block
- Learn more about how to invoke Dapr’s Service Invocation with:
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