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My note on Azure Functions

3 Hosting Plans

Consumption Plan

  • an ideal serverless plan but you may encounter a cold-start phenomenon

  • You can’t use Virtual Network

Premium Plan

  • Execute the code as soon as the function is triggered

  • Virtual network support. Often the lack of this VNet support is the hurdle in adopting the function in corporate environment

Dedicated Plan

  • The same as the App Service Plan in Azure WebApp

Running functions locally

  • Start Storage Emulator

  • Start Cosmos DB Emulator, if your function uses Cosmos DB

AzureStorageEmulator.exe start
func start

Calling HTTP trigger function endpoint

You can get “Function Url” from Azure Portal. Go to function app > Functions. Select the function you are testing and then you can see a link, “Get Function Url” on the top of the page. The function url will be something like this


You can call the endpoint from Postman. If the resource is protected, you would need an Access Token to call the endpoint. Otherwise, you will get 401 Unauthorized. To get the token, use Azure CLI command,

az account get-access-token --resource=api://<your-tennant-id>/<function-resource-name>

Then you can call the endpoint.

curl --location --request POST 'https://<function-resource-name>.azurewebsites.net/api/v1/<function-name>' \
--header 'Authorization: Bearer <your-access-token>' \
--header 'Content-Type: application/json' \
--data-raw '{
    "applicationIds": "33b19e41-3d0c-433a-8f24-f39ce44c5adb"