Build Azure functions and integrate them with Azure Cosmos DB data models

Leverage Azure functions and Cosmos DB for building serverless applications (English Edition)

Hansamali Gamage

• Publisher: BPB Publications
• Year: 2021
• eBook ISBN: 9789389328387
• Topic: Computer Science
• Subtopic: Cloud Computing
• Index: Computer Science

Build Azure functions and integrate them with Azure Cosmos DB data models
Key Features

• Expert-led coverage on integrating Azure functions
  
• Industry-proven examples and best practices on implementation of Azure Cosmos DB
  
• Learn to work on performance optimization and error handling
  
• Integration of Azure function with other Azure services Description
  This book provides examples to start with Azure functions and Azure Cosmos DB. It demonstrates the features available in both of the mentioned Azure services and discusses them in detail with some real-world examples. Reading a csv file and write to a Cosmos DB table store, Read emails using Microsoft Graph API and save them in a Cosmos DB, Cosmos DB trigger function to send SMS notifications to clients, A queue trigger to create new nodes in the Cosmos DB graph data store are some of them. You will be able to see the above case studies with code samples implemented in C#.NET Core, TypeScript, and Python. It consists of a very basic example, two intermediate samples, then and an advanced level one.You will experience the triggers and input/output bindings available for a function, like queue trigger, blob trigger, and Cosmos DB trigger to name a few. Also, you will be able to see some interesting features available in Azure functions like performance optimizations, scalability of a function app, geographical distribution of the function in different locations, error handling, writing unit tests for the functions to avoid breaking changes, how to ensure a function app is secure, and then how to deploy a function, and monitor and troubleshoot a function app.At the end of this book, you will gain strong experience in using Azure functions and how to manage serverless applications seamlessly without any failure with utmost performance. What you will learn
  
• You will be able to create an Azure function and integrate it with many Azure services including the Azure Cosmos DB
  
• You will get experience implementing a function using programming languages like C#.NET Core, TypeScript, and Python.
  
• You will get hands-on experience on the performance optimizing of a function, how to scale them, how to apply security to the function app, error handling and testing in a function. Who this book is for
  This book is for developers who want to get the knowledge and experience in Azure Functions and Azure Cosmos DB. If you have a programming knowledge of.NET, TypeScript, Python, or any other programming language, it will be enough to understand the concepts and samples in this book. If you have worked with a cloud technology or have experience in any of the Azure cloud services, then it will be a definite advantage.. Table of Contents
  1. Beginning Azure Function Apps
  2. Your First Azure Function App
  3. Let's Get Started with Cosmos DB
  4. Structure Your Data in Cosmos DB
  5. Your First Cosmos DB
  6. Serverless Design Patterns
  7. Performance and Scalability of a Function App
  8. Geo-Distribution in a Function App
  9. Error Handling and Testing
  10. Secure Your Function App
  11. Deployments in a Function App
  12. Monitor and Troubleshoot Function Apps
  13. Azure Functions with Cosmos DB Table API
  14. Azure Functions with Cosmos DB SQL API
  15. Cosmos DB Trigger in Azure Function
  16. Azure Functions with Cosmos DB Gremlin API About the Author
  Hansamali Gamage is an enthusiastic and dedicated professional with over eight years of experience in.NET stack, Azure, and front-end technologies. She has also been an MVP (Azure) for three consecutive years and is a Microsoft Certified Trainer. She is a frequent speaker at tech conferences and an award-winning writer on the Microsoft Tech Net forum. Blog links: http://hansamaligamage.blogspot.com/
  LinkedIn Profile: https://www.linkedin.com/in/hansamali-gamage-37777a50/
  

CHAPTER 1

Beginning Azure Function Apps

Introduction

In the first chapter of this book, we are going to talk about the Azure serverless architecture and why we should consider using this architecture in our applications. You will then go through some real-world business scenarios in the next section of the chapter.

This chapter will give you a basic idea of all the services in the serverless platform such as Azure Functions, Logic Apps, Event Grid, and Cosmos DB. Then it will walk you through different paradigms such as applications hosted in on-prem, Iaas, PaaS, and serverless applications.

Then, it will focus more on the main topic of the book: Azure functions. It will talk about the features of functions, different service integrations on functions such as Cosmos DB, Event Grid, Storage, and Notification Hub. After that, you will be able to get a better viewpoint of the released and experimental languages; and functions supported with different runtime versions.

You can learn about the heart of the function app, triggers and bindings in the next section of the chapter. In the end, you will get an idea of the different pricing options to host a function app and check the pros and cons of it.

Prerequisites

It would be better to have these prerequisites before going through this chapter:

• You should have an Azure subscription to try out the sample applications demonstrated in the chapter.
• Experience and understanding of different Azure services
• Experience in the C# or JavaScript languages

Structure

• Azure serverless architecture
  • What is Azure serverless architecture
  • Why serverless architecture
  • Real-world case studies of serverless applications
    • A single page web application
    • Web application backend
    • Mobile application backend
    • IOT backend
    • Real-time file processing
    • Real-time stream processing
    • Automating tasks
    • SaaS Integration
  • Azure serverless platform
    • Azure Functions
    • Logic Apps
    • Event Grid
  • Before it is serverless
    • Applications in on-prem
    • IaaS
    • PaaS
    • Serverless applications
• First s teps with Azure function
  • What is an Azure function?
  • Features of Azure functions
  • Service integrations
  • Azure Cosmos DB
  • Azure Event Hub
  • Azure Event Grid
  • Azure Notification Hub
  • Azure Service Bus
  • Azure Storage
    • Blob storage
    • Azure file storage
    • Queue storage
    • Table storage
  • Azure Logic Apps
  • Azure SignalR
  • Microsoft Graph
  • Power BI
  • Twilio API
  • SendGrid API
• Language support for functions
  • C#
  • F#
  • JavaScript
  • Java
  • Python
  • TypeScript
  • Php
  • Batch
  • Bash
  • Powershell
• Triggers and bindings
  • Triggers
    • HttpTrigger
    • TimerTrigger
    • CosmosDBTrigger
    • BlobTrigger
    • QueueTrigger
    • EventGridTrigger
    • EventHubTrigger
    • ServiceBusTrigger
    • SendGridTrigger
    • GraphAPITrigger
    • NotificationHubTrigger
    • SignalRTrigger
    • TableStorageTrigger
  • Bindings
    • Azure Storage
      

      Blob Storage
      

      Queue Storage
      

      Table Storage
      

      Cosmos DB
      

      Event Grid
      

      Event Hub
      

      Http and Webhook
      

      Microsoft Graph
      

      Mobile Apps
      

      Notification Hub
      

      SendGrid
      

      Service Bus
      

      SignalR
      

      Timer
      

      Twilio
• Type of functions
  • Serverless web applications
  • Serverless mobile backend
  • Timer-based processing
  • Real-time file processing
  • Real-time stream processing
  • Real-time bot processing
• Pricing in Azure functions
  • Consumption plan
    • Function scaling in consumption plan
    • Billing in consumption plan
  • App Service Plan
    • Function scaling in app service plan
    • Billing in app service plan
    • When to use app service plan

Objective

• You will get an understanding of Azure serverless architecture and different application deployment paradigms like IaaS, PaaS, and serverless.
• You will get an understanding of the Azure functions and their features. Moreover, the services that you can integrate with functions such as Cosmos DB, Event Hub, Service Bus, Storage, and Logic Apps and third party services such as Twilio API and SendGrid.
• Then you will get an idea of language support for functions in different runtime versions along with experimental languages.
• Triggers and bindings on an Azure function are the primary building blocks in a function app; you will get a basic idea of them as well.
• Finally, you will cover an important part when deciding to move your code to an Azure function which is pricing plans. You’ll get an idea of different pricing plans available, their features, and when to use which plan.

Azure serverless architecture

In the first section of this chapter, let’s see what Azure serverless architecture is, why we need to go for serverless architecture, and what are its benefits. Then, let’s see some real-world scenarios where Azure serverless architecture is used and try to understand the applicability of it in our business domain.

Let’s explore Azure serverless platforms such as Azure Functions, Azure Logic Apps, and Azure Event Grid in detail and their features. You will get a basic understanding of these three Azure services under the serverless architecture. This book is going to give you a high-level understanding of the Azure functions using hands-on demos and real-world business scenarios.

The final section of this chapter describes the application deployment paradigms from applications deployed in a physical on-prem server, and then Infrastructure as a Service (IaaS) which provides a virtual environment to deploy your applications through virtual machines or hyper-v without worrying about the scaling and resource management. After IaaS, it talks about Platform as a Service (PaaS) that provides an environment to host your application without worrying about the operating system updates or security patches.

If you want to deploy a .NET web application, you will get all the required packages and libraries to host your application in this container and there is no need to install them manually. In the end, we will explore the latest serverless architecture after walking through all the paradigms and exploring its features. The serverless platform is a microservice-based architecture that focuses on application development instead of the platform. You can focus only on the application. There is no need to think about the host it’s running. When it comes to the pricing, in previous paradigms, you had to pay for the continuous running application. But in serverless code, you only pay for what you use in the application and only for the time the application runs.

What is Azure serverless architecture?

Azure serverless architecture focuses on developing applications faster without worrying about the application infrastructure. So, we don’t have to handle server or infrastructure. There is no need to worry about the operating system, its infrastructure, or configurations. We can only focus on the function implementation; in fact, server management and capacity planning is invisible to us and handled by Azure. Serverless code is event-driven; it works with triggers and bindings. Let’s talk about triggers and bindings in detail in the later stages of this chapter.

Why serverless architecture

Let’s see why serverless architecture is essential in real-world business applications. What are the features in that architecture and what is their usage?

• Build apps faster using serverless functions.
• There is no need to handle server or infrastructure and there are no administrative tasks.
• We don’t have to worry about the operating system, its configurations
• We can focus only on the function implementation and business logic.
• Applications can be scaled on demand without worrying about the infrastructure.
• Applications have high availability.
• Service billing is based on pay as you go: the number of resources consumed or the time our code is running.
• Create modern applications with real-time triggers and bindings
• Integrate Azure services such as Cosmos DB, Logic Apps, or else, use third-party services such as SendGrid and Twilio SMS API
• Work with intelligent services such as Azure machine learning and cognitive services

Real-world case studies of serverless applications

We have understood the features of serverless code and why we should go for a serverless architecture in the previous sections. Let’s explore some real-world case studies that used serverless code in their applications.

A single-page web application

We can create a SPA with a REST API service backend and deploy it into Azure. Single Page Application (SPA) will dynamically load the content to the page instead of a full-page load from the server. Angular, React, Vue, and, Ember JS are the most popular SPA frameworks to build web applications. In this way, you can use an Azure function to host your site and its pages and App calls functions using a webhook url and process its data. If we deploy a web application in a serverless environment, it will reduce the deploymen...

Table of contents

• Cover Page
• Title Page
• Copyright Page
• Dedication Page
• About the Author
• About the Reviewer
• Preface
• Errata
• Table of Contents
• 1. Beginning Azure Function Apps
• 2. Your First Azure Function App
• 3. Let’s Get Started with Cosmos DB
• 4. Structure Your Data in Cosmos DB
• 5. Your First Cosmos DB
• 6. Serverless Design Patterns
• 7. Performance and Scalability of a Function App
• 8. Geo-Distribution in a Function App
• 9. Error Handling and Testing
• 10. Secure Your Function App
• 11. Deployments in a Function App
• 12. Monitor and Troubleshoot Function Apps
• 13. Azure Functions with Cosmos DB Table API
• 14. Azure Functions with Cosmos DB SQL API
• 15. Cosmos DB Trigger in Azure Function
• 16. Azure Functions with Cosmos DB Gremlin API
• Index