Attribute | Details |
---|---|
Dapr runtime version | v0.11 |
Language | TypeScript |
Environment | Local |
This tutorial and sample demonstrates how to use Dapr in a TypeScript application. You will deploy a TypeScript app that reads and write state via Dapr. The following architecture diagram illustrates the components that make up this sample:
This sample requires you to have the following installed on your machine:
- Docker
- Node.js version 8 or greater
- Typescript:
npm install -g typescript
- Postman [Optional]
Follow instructions to download and install the Dapr CLI and initialize Dapr with dapr init
.
Now that Dapr has been setup locally, clone the repo, then navigate to the hello-typescript
sample:
git clone https://github.com/dapr/samples.git
cd samples/hello-typescript
In the app.ts
file you'll find a simple express
application, which exposes two route handlers.
THe Dapr client is initialized as below:
var client = new dapr.dapr_grpc.DaprClient(
`localhost:${daprGrpcPort}`, grpc.credentials.createInsecure());
Next, take a look at the neworder
handler:
app.post('/neworder', (req, res) => {
const data = req.body.data;
const orderId = data.orderId;
console.log("Got a new order! Order ID: " + orderId);
var save = new dapr.dapr_pb.SaveStateRequest();
save.setStoreName(stateStoreName)
var state = new dapr.common_pb.StateItem();
state.setKey("order");
state.setValue(Buffer.from(JSON.stringify(data)));
save.addStates(state);
client.saveState(save, (error, _) => {
if (error) {
console.log(error);
res.status(500).send({message: error});
} else {
console.log("Successfully persisted state.");
res.status(200).send();
}
});
});
The endpoint neworder
will receive and handle messages. The handler logs the incoming order id ans persists it using Dapr's state store.
Finally, check the order
handler:
app.get('/order', (_req, res) => {
var get = new dapr.dapr_pb.GetStateRequest();
get.setStoreName(stateStoreName)
get.setKey("order");
client.getState(get, (error, response) => {
if (error) {
console.log(error);
res.status(500).send({message: error});
} else {
console.log('Got!');
console.log(String.fromCharCode.apply(null, response.getData()));
res.status(200).send(String.fromCharCode.apply(null, response.getData()));
}
});
});
It will retrieve the state persisted with order
key and return the content as the payload in the HTTP response.
-
Install dependencies:
npm install
This will install
typescript
,express
andbody-parser
, among any other dependencies that are shown inpackage.json
. -
Run Node.js app with Dapr:
npm start
The command should output text that looks like the following, along with logs:
Starting Dapr with id nodeapp. HTTP Port: 3500. gRPC Port: 9165
You're up and running! Both Dapr and your app logs will appear here.
...
Note: The
start
command is defined in thepackage.json
file asdapr run --app-id=nodeapp --dapr-http-port=3500 --app-port=3000 -- ts-node-dev --inspect --ignore-watch node_modules app.ts
.
Now that Dapr and the Node.js app are running, you can POST messages against it, using different tools. Note: here you are POSTing against port 3000 - if you used a different port, be sure to update your URL accordingly.
First, POST the message by using Dapr cli in a new command line terminal:
Windows Command Prompt
dapr invoke --verb POST --app-id nodeapp --method neworder --data "{\"data\": { \"orderId\": \"41\" } }"
Windows PowerShell
dapr invoke --verb POST --app-id nodeapp --method neworder --data '{\"data\": { \"orderId\": \"41\" } }'
Linux or MacOS
dapr invoke --verb POST --app-id nodeapp --method neworder --data '{"data": { "orderId": "41" } }'
Next, GET the content of the persisted order:
dapr invoke --verb GET --app-id nodeapp --method order
And the response should be:
{"orderId":"41"}
Now, you can also do the same using curl
with:
curl -XPOST -d @sample.json -H "Content-Type:application/json" http://localhost:3500/v1.0/invoke/nodeapp/method/neworder
curl -XGET http://localhost:3500/v1.0/invoke/nodeapp/method/order
Or, you can also do this using the Visual Studio Code Rest Client Plugin
POST http://localhost:3500/v1.0/invoke/nodeapp/method/neworder
{
"data": {
"orderId": "42"
}
}
GET http://localhost:3500/v1.0/invoke/nodeapp/method/order
You can also use the Postman GUI.
Open Postman and create a POST request against http://localhost:3500/v1.0/invoke/nodeapp/method/neworder
In your terminal window, you should see logs indicating that the message was received and state was updated:
== APP == Got a new order! Order ID: 42
== APP == Successfully persisted state.
Now, to make sure that the method definition was successfully invoked, verify that the the response is:
Got a new order! Order ID: 41
Additionally the log in the node application started with Dapr should be
== APP == Got a new order! Order ID: 41
In this sample, the project is setup in a way that code changes do not require the app to be restarted. Make a simple code change and see how it is loaded without the need to restart Dapr runtime or the app. The following log message can be modified and a new GET request made to reproduce this feature.
console.log('Found order!');
To stop your service from running, simply stop the "npm" process. Alternatively, you can spin down your service with the Dapr CLI "stop" command. For example, to spin down the service, run this command in a new command line terminal:
dapr stop --app-id nodeapp
To see that services have stopped running, run dapr list
, noting that your services no longer appears!
Now that you've gotten Dapr running locally on your machine with state store, consider these next steps:
- Learn more about Dapr in the Dapr overview documentation.
- Explore other Dapr concepts such as building blocks and components in the Dapr concepts documentation.
- Look at other APIs available in the Dapr's JavaScript SDK.