Aspire.Hosting.Azure.Functions does not use the typical connection string naming convention

[matthewhartz-qmerit]

Is there an existing issue for this?

• [x] I have searched the existing issues

Describe the bug

When configuring azure functions projects and passing in a reference to blob storage I noticed that the way we access connection strings in the functions application does not work the same was as an API service.

For example, I have this code: builder.AddProject<Projects.ApiService>("apiservice") .WithExternalHttpEndpoints() .WithReference(rabbitMQ) .WithReference(cosmos) .WithReference(blobs) .WaitFor(rabbitMQ) .WaitFor(blobs);

builder.AddAzureFunctionsProject<Projects.Functions>("functions") .WithExternalHttpEndpoints() .WithHostStorage(storage) .WithReference(blobs) .WaitFor(blobs) .WaitFor(storage);

but when access the connection string in the function I get null. var blobConnectionString = context.Configuration.GetConnectionString("Blobs")!;

My work around was to change the with reference to this: builder.AddAzureFunctionsProject<Projects.PanelInsights_Functions>("functions") .WithExternalHttpEndpoints() .WithHostStorage(storage) .WithReference(blobs, "ConnectionStrings:Blobs") .WaitFor(blobs) .WaitFor(storage);

Expected Behavior

.WithReference(blobs)

paired with: var blobConnectionString = context.Configuration.GetConnectionString("Blobs")!;

should get the value of the connection string

Steps To Reproduce

• Set up an API project and a Functions project
• Connect them using code provided above
• Verify how you access the connection string in both api project and functions project
• Notice that in the function project it returns null

Exceptions (if any)

No response

.NET Version info

9.0.7

Anything else?

No response

[davidfowl]

That's right, it's because functions projects are a bit strange with respect to configuration. Using the typical naming pattern breaks functons bindings so we use the alternative configuration pattern when applying configuration to functions.

[biltongza]

@davidfowl could you please elaborate/point to some docs on what the "alternative configuration pattern" is/means?