jeffhollan/azure-functions-dapr-extension

Azure Functions dapr extensions

⚠️ This is a proof of concept extensions. It is not intended for production ⚠️

The Azure Functions dapr extension allows you to easily interact with the dapr APIs from an Azure Function. This would work in local and Kubernetes scenarios.

State management

The state management input and output bindings allow you to write state from your Azure Function.

JavaScript Example

module.exports = async function (context, req) {
    context.log('JavaScript HTTP trigger function processed a request.');

    // input binding
    var data = context.bindings.daprInput;

    // output binding
    context.bindings.daprOutput = {
        // stateStore: 'statestore-if-not-in-function.json'
        // key: 'key-if-not-in-function.json'
        value: data
    };

    context.res = {
        status: 200
    };
};

C# Example

[FunctionName("MyFunction")]
public static async Task<IActionResult> Run(
    [HttpTrigger(AuthorizationLevel.Function, "get", Route = "state/{key}")] HttpRequest req,
    // Input binding
    [DaprState(StateStore = "statestore", Key = "{key}")] string inputState,
    // Output binding - to override statestore or key bind to SaveStateOptions
    [DaprState(StateStore = "statestore", Key = "{key}-output")] IAsyncCollector<string> outputState,
    ILogger log)
{
    // ...
    await outputState.AddAsync(inputState);
}

Can bind to string, Stream, byte[], or SaveStateOptions.

Properties

Property Name	Description
DaprAddress	The address to reach dapr. Default is http://localhost:3500
StateStore	Name of the state store
Key	Key used to store the data

Invoke method

The invoke method output binding allows your function to invoke a downstream dapr app.

JavaScript Example

module.exports = async function (context, req) {
    context.log('JavaScript HTTP trigger function processed a request.');

    // output binding
    context.bindings.daprInvoke = {
        // appId: 'appId-if-not-in-function.json'
        // methodName: 'methodName-if-not-in-function.json'
        // httpVerb: `httpVerb-if-not-in-function.json'
        body: data
    };

    context.res = {
        status: 200
    };
};

C# Example

[FunctionName("MyFunction")]
public static async Task<IActionResult> Run(
    [HttpTrigger(AuthorizationLevel.Function, "get", Route = "invoke/{methodName}")] HttpRequest req,
    [DaprInvoke(AppId = "other-function", MethodName = "{methodName}", HttpVerb = "post")] IAsyncCollector<InvokeMethodOptions> output,
    ILogger log)
{
    // ..

    var outputContent = new InvokeMethodOptions(){
        Body = "SomeData"
    };

    await output.AddAsync(outputContent);
}

Properties

Property Name	Description
DaprAddress	The address to reach dapr. Default is http://localhost:3500
AppId	ID of the app to invoke
MethodName	Name of the method to invoke
HttpVerb	Http verb to use during invoke (e.g. get, put, post)
Body	Optional. Any content to send with invoke