Azure_HTTPTriggerFunctionSample

Description

This is a sample application which uses a HTTP trigger function to process a message. I have created this for my learning purpose and to improve my technical skils and wanted to implemented what i have learnt in some crash course.

Features

• POST message to cloud
• All request to the triggered are Audited
• Once message is processed the similar information can be posted in azure queue for further process
• Azure queue are completely configurable from localSettings.json file
• Supports both Service bus queue and Storage queue
• Queue can be created dynamicaly on the fly
• Health check endpoint to verify the app status

Technology Used

• Azure Function (HTTP Trigger)
• .Net Core
• Entity Framework Core
• Azure storage
• Azure service bus

Concepts Covered

• Dependency Injection
• Delegates
• Static
• Interface implementation
• SOLID Principle
• Linq

Tools used (needed to work on this)

• Visual Studion 2019

How to configure

Once the repo gets cloned to your local machine and open the solution file from your loacl visual studio IDE. Bfore run and explore there are few configuraions has to be modified according to your development environment

Connection Strings

This the primay settings we need to take care of and below are varios typers of connection string we have used in this project

Data base

As this application tracking each request and process the request we have been making entries in data base. please change your connection string in the settings json file

 "SampleApp_ConnectionString": 
  "Data Source=<DB serever>;Initial Catalog=SampleApp;Integrated Security=True;TrustServerCertificate=False;ApplicationIntent=ReadWrite;MultiSubnetFailover=False"    

Storage Account

As this application send the mesage to the storage account queue based on configuraion. please change your connection string in the settings json file

 "SampleApp_StorageAccount_ConnectionString": "<place your storage account connection string>"    

Service Bus

As this application send the mesage to the Service bus queue based on configuraion. please change your connection string in the settings json file

     "SampleApp_ServiceBus_ConnectionString": <place your connection string>

Queue Name

This application provide option to configure the queue name based on need, we have inrtroduced this configuration. Make sure the queue name must be in lower case to avoid failure

     "SampleApp_ServiceBus_QueueName": <Service bus queue>,
     "SampleApp_StorageQueueName": <storage queue>,

Configuration which decides to use Azure service bus OR Storage account

Based on this setting application post the message to either service bus or storage account

     "AzureQueueAssets": <we must use one from below with same format>
     "ServiceBus|Queue" This will post the message on to the Queue in azure service bus
     "ServiceBus|Topic" This will post the message on to the Topic in azure service bus. You could have choosen other than BASIC pricing tier when creating azure service bus. Basic tier doesn't support Topic feature.
     "StorageAccount|Queue" This will post the message on to the Queue in azure storage account

Data base set up

SQL DDL scripts are created and available under solution folder.

.    
├── SampleFunctionApp
│   └── SampleApp.Shared
│       └── SQLScripts
│         └── DDL Script.sql

Sample message format

Since this app is using HTTP trigger the sample post request body is available under SampleFunctionApp\SampleApp.Shared\SQLScripts (Message)

{
  "UserName": "palkalaislevand",
  "FirstName": "Palkalaiselvan",
  "LastName": "Dhamotharan",
  "EmailAddress": "[email protected]",
  "Department": "Information Technology"
}

Custom Key-based Authentication

To set up custom key-based authentication, follow these steps:

1. Add a custom key to your local.settings.json file:

   {
     "IsEncrypted": false,
     "Values": {
       "AzureWebJobsStorage": "UseDevelopmentStorage=true",
       "FUNCTIONS_WORKER_RUNTIME": "dotnet",
       "SampleApp_ConnectionString": "Data Source=(localdb)\\ProjectsV13;Initial Catalog=SampleApp;Integrated Security=True;TrustServerCertificate=False;ApplicationIntent=ReadWrite;MultiSubnetFailover=False",
       "SampleApp_ServiceBus_ConnectionString": "Endpoint=sb://developmentaccount.servicebus.windows.net/;SharedAccessKeyName=RootManageSharedAccessKey;SharedAccessKey=2m+dy8rXboZmHrDdqkDod46Hg/DThH9aYEM1ZYFWUpo=",
       "SampleApp_ServiceBus_QueueName": "sbuserdetailsqueue",
       "SampleApp_ServiceBus_TopicName": "sbuserdetailstopic",
       "SampleApp_StorageAccount_ConnectionString": "DefaultEndpointsProtocol=https;AccountName=storaccpocctr;AccountKey=SzlfpjbTy+VpR0DqJHt6Wb4/TP1MEPV0eIsjHepxSxXQ5e3RitFTwwz5clAxWxXAloNO2Hc2yZvePHks65I/qg==;EndpointSuffix=core.windows.net",
       "SampleApp_StorageQueueName": "squserdetailsqueue",
       "AzureQueueAssets": "ServiceBus|Queue",
       "CustomAuthKey": "your-custom-key"
     }
   }

2. Update your HTTP trigger functions to use the custom key for authentication. For example, in UserDetailsTrigger.cs, pass the custom key to the Authorize method:

   [FunctionName(nameof(UserDetailsTrigger))]
   public async Task<IActionResult> Run([HttpTrigger(AuthorizationLevel.Function, "post", Route = "v1/userdetails")] HttpRequest req,
       ILogger logger)
   {
       string customKey = req.Headers["CustomAuthKey"];
       return await Request(req, logger)
           .Authorize(AuthorizationLevel.Function, customKey)
           .Run(Work);
   }

3. Implement the ValidateCustomKey method in BaseHttpTrigger.cs to perform custom key-based authentication:

   public class BaseHttpTrigger
   {
       // Existing code...
   
       public bool ValidateCustomKey(string customKey)
       {
           string expectedKey = Environment.GetEnvironmentVariable("CustomAuthKey");
           return customKey == expectedKey;
       }
   }

4. Update the Authorize method in BaseHttpTrigger.cs to accept a custom key and validate it using ValidateCustomKey:

   public RequestContext Authorize(AuthorizationLevel authorizationLevel, string customKey)
   {
       _authorizationLevel = authorizationLevel;
       if (!ValidateCustomKey(customKey))
       {
           throw new UnauthorizedAccessException("Invalid custom key");
       }
       return this;
   }