This non static class is required for constructor injection in Azure function and collection of custom telemetry events.
If we create an azure function app in visual studio, it creates default with static keyword like this:
public static async Task<IActionResult> Run(
[HttpTrigger(AuthorizationLevel.Function, "get", "post", Route = null)] HttpRequest req,
ILogger log)
{
telemetryClient.TrackEvent(new Exception("Function started"));
}
But to use constructor dependency injection (for Temeltry client, i am using it), we need to remove static keyword.
public Function1(TelemetryClient telemetryClient)
{
_telemetryClient = telemetryClient;
}
Previously, Azure Functions only supported static classes/methods. This restriction made DI via constructor impossible. However later the support for non-static classes/methods was implemented (see Support Instance Functions).
So if you need to use DI via constructor, just change it to non-static. There are no consequences.
This is not entirely true though - I just ran into some trouble with non static timer triggered functions. In my case I needed dependency injection in terms of entity framework, but this non static instance is now causing me trouble in order to call the admin endpoint to trigger the function when doing development locally.
See more on how to normally invoke static timer triggered functions here:
What is the simplest way to run a timer-triggered Azure Function locally once?
Related
I have a working .NET6 in-proc Azure Function. I'm in the process of converting it to an isolated worker process (out-of-proc) .net7 function.
I have a HttpTrigger function that should get a file from the blob-storage. Since the blob-storage is case-sensitive and all files are saved in upper-case, I need to make the input upper-case as well.
With the in-proc function, I did that by injecting Microsoft.Azure.WebJobs.IBinder binder and then use binder.BindAsync<byte[]>(new Microsoft.Azure.WebJobs.BlobAttribute($"%BlobContainerName%/{fooUpper}", FileAccess.Read)
This is the .net6 in-proc function:
[Function(nameof(GetFile))]
public async Task<IActionResult> GetFile(
[HttpTrigger(AuthorizationLevel.Function, "get", Route = "bar/{foo}")] HttpRequest req,
Microsoft.Azure.WebJobs.IBinder binder, Microsoft.Azure.WebJobs.ExecutionContext context, string foo)
{
// The file name is always upper-case:
var fooUpper = foo.ToUpperInvariant();
var blobStream = await binder.BindAsync<byte[]>(
new Microsoft.Azure.WebJobs.BlobAttribute($"%BlobContainerName%/{fooUpper}", FileAccess.Read),
req.FunctionContext.CancellationToken).ConfigureAwait(false);
return await ExecuteAsync(fooUpper, context.FunctionDirectory, blobStream,
req.FunctionContext.CancellationToken)
.ConfigureAwait(false);
}
Of course, I tried migrating this function to a .net7 isolated function by replacing HttpRequest req with HttpRequestData req and it compiles but when I run it binder is always null.
What is the isolated function version of my function?
Do I need to create a custom attribute?
Or create some middleware that makes the URL upper-case?
Or should I create a service that I register during start-up and use with DI in the function class?
Please advice.
Check if my below findings helpful to fix your issue:
BlobContainerClient is no longer working in isolated mode
AFAIK, BlobContainerClient should work with the .NET Isolated Process Version 7 in Azure Functions using Azure.Storage.Blobs NuGet Package as shown in this SO Answer #75015570 by the user #HariKrishna and MS DOC.
If you use the NuGet Package Azure.Storage.Blobs, you can initialize the BlobContainerClient class-objects which is compatible in .NET Isolated Process and for working with the Blob Container Objects, you have to initialize the BlobServiceClient for Connecting to Storage Account and getting access to the Blob Container.
public HttpResponseData Run([Microsoft.Azure.Functions.Worker.HttpTrigger(AuthorizationLevel.Function, "get", Route = "bar/{foo}")] HttpRequestData req,
BlobContainerClient blobContainerClient, IBinder binder, ExecutionContext executionContext)
Here is the GitHub Article on Azure Functions .NET Isolated Process of using the Ibinder input parameter for data binding and there are some examples provided in the same article for working in the context of Ibinder and StorageAccountAttribute such as Microsoft.Azure.WebJobs.BlobAttribute.
I am unclear on how the scopeId parameter of the SingletonAttribute works. Specifically does the scopeId parameter work for HTTP Trigger Azure Functions when you bind it to a route parameter? How does the binding work? What variables/values can I bind to?
For example:
[Singleton("{input}", Mode = SingletonMode.Listener)]
public async Task<IActionResult> Run([HttpTrigger(AuthorizationLevel.Anonymous, "post", Route = "v1/{input:length(1,30)}")] Microsoft.AspNetCore.Http.HttpRequest req, string input, ILogger log) {
return new OkObjectResult(input + " world");
}
A HTTP POST request to this function with the URI 'v1/hello' would return: "Hello world".
But would the Singleton attribute work such that all requests to 'v1/hello' would run serially whereas two simultaneous requests with one to 'v1/first' and the other to 'v1/second' would run in parallel?
I see from this answer that for Service Bus Triggers you can bind to properties within the Message object directly.
Also in the documentation there is an example of a Queue Trigger Function with scopeId binding to a property in the WorkItem object.
It's unclear what's supported for HTTP Trigger Functions.
You have two ways to implement singleton mode in Azure function.
The first:
You can do this by setting WEBSITE_MAX_DYNAMIC_APPLICATION_SCALE_OUT or maxConcurrentCalls.
Singleton Azure function running as separate instances
The second type:
Create a complete Function project, similar to webapp, and implement it in Configure.
Use dependency injection in .NET Azure Functions
public class Startup : FunctionsStartup
{
public override void Configure(IFunctionsHostBuilder builder)
{
builder.Services.AddHttpClient();
builder.Services.AddSingleton<IMyService>((s) => {
return new MyService();
});
builder.Services.AddSingleton<ILoggerProvider, MyLoggerProvider>();
}
}
I got a reply from Microsoft on GitHub: https://github.com/MicrosoftDocs/azure-docs/issues/69011#issuecomment-771922910
"Binding expressions for Singleton have the same behavior as those for general input/output bindings. That is, any binding data from the trigger is available for reference.
In the case of HttpTrigger, that includes any POCO members if you’re binding to a POCO type, as well as any route parameters.
In regards to your code, SingletonMode.Listener is not what you want for your requirement. If you're just trying to serialize individual invocations of the function then you should use the default mode, i.e. [Singleton(“{input}”)].
To answer your question – yes, this would serialize all invocations of v1/hello, allowing v1/first and v1/second to run concurrently."
I'm working on exploring the following 2 features of Azure App Configuration in Azure Function's Http Trigger
Externalizing the App Settings
Feature Flags
Below is how i'm getting the reference of the configuration
So, when I use _configuration["SomeAppSettingKey"], I'm able to retrieve the value. So, I'm able to achieve #1 feature mentioned above.
My Question is, How do we retrieve the Feature Flag information? I have tried the below ways.
I would appreciate if someone could help me in understanding how to retrieve it in Azure Functions (I'm using V3)? A Sample code or any reference to documentation would be helpful.
Thanks.
Update1:
I can deserialize the json content as shown below. But, is this is the right approach?
Where FeatureManager is a class that I have defined as shown below.
all you need is to call UseFeatureFlags() function as part of AddAzureAppConfiguration to let the App Configuration provider know you want to use feature flags. An example can be found following the link below. It uses the FunctionsStartup and dependency injection (DI) of Azure Functions. An instance of a feature manager is put into the DI.
https://github.com/Azure/AppConfiguration/blob/master/examples/DotNetCore/AzureFunction/FunctionApp/Startup.cs
The link below shows how you can obtain the instance of IFeatureManagerSnapshot from DI and use it as part of your Azure Functions call.
https://github.com/Azure/AppConfiguration/blob/master/examples/DotNetCore/AzureFunction/FunctionApp/ShowBetaFeature.cs
Deserialize JSON is not a good idea, every time you will add new key you need to modify your class.
private static IConfiguration Configuration { set; get; }
static Function1()
{
var builder = new ConfigurationBuilder();
builder.AddAzureAppConfiguration(Environment.GetEnvironmentVariable("ConnectionString"));
Configuration = builder.Build();
}
public static async Task<IActionResult> Run(
[HttpTrigger(AuthorizationLevel.Anonymous, "get", "post", Route = null)] HttpRequest req, ILogger log)
{
log.LogInformation("C# HTTP trigger function processed a request.");
string keyName = "TestApp:Settings:Message";
string message = Configuration[keyName];
return message != null
? (ActionResult)new OkObjectResult(message)
: new BadRequestObjectResult($"Please create a key-value with the key '{keyName}' in App Configuration.");
}
I am playing around with Azure functions and trying to setup an intricate construct of pipes and filters (the pattern). I am using Azure functions for this.
My starting point is a HTTP triggered Azure function. That collects some JSON from the body of the request and should pass this message to a Azure Service Bus.
I must be missing something here (I have done this before in RabbitMQ with console apps) but how do I post a message to a service bus from a HTTP triggered Azure function.
I found several references talking about configuring my function.json (what ever that is - im building in Visual Studio).
How does this input/output (trigger/binding) thing work - im guessing that is the problem here...or??
I have my first Azure function in place and is receiving the data from the HTTP - so far so good. But how to proceed?
** Update **
Still cant get it to Work. Got this code and it fails with an http500. (it also says i need to see the og - where is that log?)
public static class EI_WooCommerce_Hub
{
[FunctionName("EI_WooCommerce_Hub")]
[return: ServiceBus("eilogging", Connection = "EIIntegrationServiceBusConnection")]
public async static Task<string> Run([HttpTrigger(AuthorizationLevel.Function, "get", "post", Route = "EIWooCommerceHub/name/")]HttpRequestMessage req, TraceWriter log)
{
log.Info("Webhook triggered from: ");
return "Hello World to queue";
}
}
** Update 2 **
This seems to be a config problem. In the application settings on the function app I kept getting an authorization error for the servicebus. I added the default "AzureWebJobsServiceBus" setting with the connectionstring, then it worked. It could not pick up my own connection string for some reason.
You should use Service Bus output binding. Since you mentioned Visual Studio, I assume C#. The simplest ever example looks like this:
[FunctionName("ServiceBusOutput")]
[return: ServiceBus("myqueue", Connection = "ServiceBusConnection")]
public static string ServiceBusOutput([HttpTrigger] dynamic input)
{
return input.Text;
}
Then add an application setting called ServiceBusConnection with the connection string to a namespace with queue myqueue (or rename in attribute constructor).
You can find more in Azure Service Bus bindings for Azure Functions - Output.
When you build in Visual Studio, then the function.json is created automatically. All you have to do is to define your triggers and output as attributes of the function parameters (see here: https://learn.microsoft.com/en-us/azure/azure-functions/functions-bindings-service-bus#output)
A minimalistic example:
[FunctionName("HttpTriggerCSharp")]
public static async Task<HttpResponseMessage> Run(
[HttpTrigger(AuthorizationLevel.Function, "get")] HttpRequestMessage req,
[ServiceBus("myqueue")] out string sbMessage,
TraceWriter log)
{
log.Info("C# HTTP trigger function processed a request.");
// parse query parameter
string name = req.GetQueryNameValuePairs()
.FirstOrDefault(q => string.Compare(q.Key, "name", true) == 0)
.Value;
sbMessage = name;
}
I have a series of Azure Functions, and I'd like to keep track of them by the InovcationId. In Application Insights, the InvocationId is called the operation_Id.
What I'm trying to do is set the operation_Id to be the same across several different Azure Functions.
I can read this property inside the Azure Function when I pass in ExecutionContext by following this answer, but I can't seem to alter it. Is there some way to change this value from inside the Azure Function?
public static class TestOperationId
{
[FunctionName("TestOperationId")]
public static async Task<HttpResponseMessage> Run([HttpTrigger(AuthorizationLevel.Function, "get", "post", Route = null)]HttpRequestMessage req,
ILogger log,
ExecutionContext exeCtx
)
{
var input = await req.Content.ReadAsStringAsync();
log.Info(input);
exeCtx.InvocationId = Guid.Parse(input);
return req.CreateResponse(HttpStatusCode.OK);
}
}
The definition for the InvocationId field is defined as
Provides the invocation ID, uniquely identifying the current invocation
Azure Functions doesn't provide changing this, as it would mean that code could override the platform's methods to detect unique invocations of Functions, which would interfere with things like Billing and Metrics for the platform.
It sounds like what you really want is cross-function correlation. There is work being done with the Application Insights team to help support this, but in the meantime, you can see solutions that others are currently utilizing, like here.