Azure WebJobs Web PubSub client library for .NET

This extension provides functionality for receiving Web PubSub webhook calls in Azure Functions, allowing you to easily write functions that respond to any event published to Web PubSub.

Source code |Package |API reference documentation |Product documentation |Samples

Getting started

Install the package

Install the Web PubSub extension withNuGet:

dotnet add package Microsoft.Azure.WebJobs.Extensions.WebPubSub

Prerequisites

You must have anAzure subscription and an Azure resource group with a Web PubSub resource. Follow thisstep-by-step tutorial to create an Azure Web PubSub instance.

Authenticate the client

In order to let the extension work with Azure Web PubSub service, you will need to provide a validConnectionString.

You can find theKeys for you Azure Web PubSub service in theAzure Portal.

TheAzureWebJobsStorage connection string is used to preserve the processing checkpoint information as required refer toStorage considerations

For the local development use thelocal.settings.json file to store the connection string,<connection-string> can be set toWebPubSubConnectionString as default supported in the extension, or you can set customized names by mapping it withConnection = <connection-string> in function binding attributes:

{  "Values": {    "AzureWebJobsStorage": "UseDevelopmentStorage=true",    "<connection-string>": "Endpoint=https://<webpubsub-name>.webpubsub.azure.com;AccessKey=<access-key>;Version=1.0;"  }}

When deployed use theapplication settings to set the connection string.

Key concepts

Using Web PubSub input binding

Please follow theinput binding tutorial to learn about using this extension for buildingWebPubSubConnection to create Websockets connection to service with input binding.

Using Web PubSub output binding

Please follow theoutput binding tutorial to learn about using this extension for publishing Web PubSub messages.

Using Web PubSub trigger

Please follow thetrigger binding tutorial to learn about triggering an Azure Function when an event is sent from service upstream.

InConnect andUserEvent events, function will respect return values to send back service. Then service will depend on the response to proceed the request or else. The responses and events are paired. For example,Connect will only respectConnectEventResponse orEventErrorResponse, and ignore other returns. WhenEventErrorResponse is returned, service will drop client connection. Please follow thetrigger binding return value tutorial to learn about using the trigger return value.

Examples

Functions that uses Web PubSub input binding

public static class WebPubSubConnectionBindingFunction{    [FunctionName("WebPubSubConnectionBindingFunction")]    public static WebPubSubConnection Run(        [HttpTrigger(AuthorizationLevel.Anonymous, "get", "post")] HttpRequest req,        [WebPubSubConnection(Hub = "hub", UserId = "{query.userid}", Connection = "<connection-string>")] WebPubSubConnection connection)    {        Console.WriteLine("login");        return connection;    }}

Functions that uses Web PubSub output binding

public static class WebPubSubOutputBindingFunction{    [FunctionName("WebPubSubOutputBindingFunction")]    public static async Task RunAsync(        [HttpTrigger(AuthorizationLevel.Anonymous, "get", "post")] HttpRequest req,        [WebPubSub(Hub = "hub", Connection = "<connection-string>")] IAsyncCollector<WebPubSubAction> action)    {        await action.AddAsync(WebPubSubAction.CreateSendToAllAction("Hello Web PubSub!", WebPubSubDataType.Text));    }}

Functions that uses Web PubSub trigger

[FunctionName("WebPubSubTriggerFunction")]public static void Run(    ILogger logger,    [WebPubSubTrigger("hub", WebPubSubEventType.User, "message")] UserEventRequest request,    string data,    WebPubSubDataType dataType){    logger.LogInformation("Request from: {user}, data: {data}, dataType: {dataType}",        request.ConnectionContext.UserId, data, dataType);}

Functions that uses Web PubSub trigger return value

public static class WebPubSubTriggerReturnValueFunction{    [FunctionName("WebPubSubTriggerReturnValueFunction")]    public static UserEventResponse Run(        [WebPubSubTrigger("hub", WebPubSubEventType.User, "message")] UserEventRequest request)    {        return request.CreateResponse(BinaryData.FromString("ack"), WebPubSubDataType.Text);    }}

Functions that handles MQTT Client "connect" event

[FunctionName("mqttConnect")]public static WebPubSubEventResponse Run(        [WebPubSubTrigger("hub", WebPubSubEventType.System, "connect", ClientProtocols = WebPubSubTriggerAcceptedClientProtocols.Mqtt)] MqttConnectEventRequest request,        ILogger log){    if (request.ConnectionContext.ConnectionId != "attacker")    {        return request.CreateMqttResponse(request.ConnectionContext.UserId, Array.Empty<string>(), new string[] { "webpubsub.joinLeaveGroup.group1", "webpubsub.sendToGroup.group2" });    }    else    {        if (request.Mqtt.ProtocolVersion == MqttProtocolVersion.V311)        {            return request.CreateMqttV311ErrorResponse(MqttV311ConnectReturnCode.NotAuthorized);        }        else        {            return request.CreateMqttV50ErrorResponse(MqttV500ConnectReasonCode.NotAuthorized);        }    }}

Troubleshooting

Please refer toMonitor Azure Functions for troubleshooting guidance.

Next steps

Read theintroduction to Azure Function orcreating an Azure Function guide.

Contributing

See ourCONTRIBUTING.md for details on building,testing, and contributing to this library.

This project welcomes contributions and suggestions. Most contributions requireyou to agree to a Contributor License Agreement (CLA) declaring that you havethe right to, and actually do, grant us the rights to use your contribution. Fordetails, visitcla.microsoft.com.

This project has adopted theMicrosoft Open Source Code of Conduct.For more information see theCode of Conduct FAQor contactopencode@microsoft.com with anyadditional questions or comments.