Azure Functions are a powerful tool for building scalable apps. They allow developers to create serverless functions that can handle a high volume of requests without worrying about scaling or maintenance.
With Azure Functions, you can deploy your functions to the cloud in just a few clicks. This is made possible by the Azure Functions runtime, which automatically scales to meet changing demand.
Developers can choose from a range of triggers and bindings to create custom functions that integrate with their existing systems and services. This flexibility is a key benefit of using Azure Functions.
By leveraging Azure Functions, you can reduce the complexity and cost associated with managing your own servers and infrastructure.
Building and Deployment
Building and deployment of Azure Functions can be a straightforward process. You can create a Function app artifact using the .NET CLI by running the `dotnet publish` command, which restores packages, compiles the functions, and outputs all the files needed to run the Function app into a single folder.
To deploy your Function app, you can use the Azure Portal, Visual Studio, or the Azure CLI. The Azure Portal allows you to create a Function app and deploy it with a few clicks. Visual Studio provides a more comprehensive tooling experience, including the ability to debug and test your Function app locally before deploying it to Azure. The Azure CLI provides a command-line interface for deploying your Function app.
The deployment process involves transforming the build artifact, pushing it to Azure, and verifying that the application is running as expected. You can use a well-known Continuous Deployment tool, such as Azure DevOps or Octopus Deploy, to automate the deployment process. These tools provide first-class support for Azure Functions, giving you access to everything you need to deploy and configure your Function app.
Here are some deployment options:
[Build at Scale]
Building at scale is a crucial aspect of deploying serverless apps. The .NET CLI does the brunt of the work when you call dotnet publish on the project containing your functions, restoring packages, compiling the functions, and outputting all the files needed to run the Function app into a single folder.
To build a deployable Function app artifact, you'll need to call dotnet publish on your project, which will create an output folder containing all the necessary files. The output folder needs to be zipped up into a single archive for deployment.
The build process is triggered by a commit to a long-lived branch, typically via Pull Request, and happens once per commit to the long-lived branch. The process consists of building, unit testing, and archiving the output folder into a zip file.
You can use a well-known Continuous Deployment tool, such as Azure DevOps or Octopus Deploy, to deploy your Function app artifacts to Azure. Both tools have first-class support for Functions, giving you access to everything you need to deploy and configure your Function app.
Here are some benefits of using Azure DevOps for deployment:
Function
A function in Azure Functions is a deployable unit that needs to be invoked, and that's where triggers come in - they're the events that cause a single function to run.
Triggers are configured by a binding and there are several types available to cover common scenarios. Each function in a function app has its own trigger.
To make the name of the function friendly, use the FunctionName attribute, especially when you have several classes with a RunAsync function.
The output binding specifies what resource the function should connect to, and in the .NET Framework, a return statement will put the data where it belongs - in this case, the queue named greetings-queue as defined previously.
After creating a function, you can try it out by choosing to run or debug it, which starts the local web server and shows a link to URL in Rider's Terminal window.
You can also create an HTTP Request instead of testing with a URL, which is a great way to keep some sample data to send in the request without having to type it in every time you test it.
vs Web Jobs
Azure Functions and Web Jobs are both used to run background tasks in Azure, but they have some key differences. Azure Functions is built on top of Web Jobs with added capabilities.
Azure Functions can be triggered with any of the configured triggers, but it doesn't run continuously. On the other hand, Web Jobs are of two types: Triggered Web Jobs and Continuous Web Jobs.
Azure Functions support various languages like C#, F#, JavaScript, node.js, and more. Web Jobs also support various languages like C#, F#, JavaScript, and more.
Azure Functions is a separate App Service that runs in the App Service Plan. Web Jobs, on the other hand, run as a background service for the App services like Web App, API Apps, and mobile Apps.
Here's a quick comparison of Azure Functions and Web Jobs:
Resource Creation
Creating a resource on Azure is a crucial step in deploying your Azure Function. You can create a Function app manually through the Create Resource option in the portal, via the Azure CLI, or by way of an ARM template, and they all work equally well.
To create a Function app, you'll need to provide some necessary details, which can be done manually or programmatically. Once you've got a running Function app, it's time to push your compiled code to the cloud.
You can create a Function app in two ways: through the Azure portal or using Visual Studio. The Azure portal method involves clicking on Create a resource, selecting Azure Functions App in the Compute section, and then clicking Create.
Runtime Versions
Azure Functions runtimes are related to the major version of .NET. You can find the equivalent .NET version for each runtime version in the table below.
Azure Functions 2.x is Generally Available, while 1.x is in maintenance mode. Migrating from 1.x to a later version is simple and straightforward, and can be done from the Azure portal itself.
API and Function Apps
Azure Functions are built and deployed with a focus on scalability and flexibility. A function is a deployable unit, and each function in a function app has its own trigger, configured by a binding.
Each function has its own trigger, which is the event that causes a single function to run. Triggers cover common scenarios, such as launching a function in response to an HTTP request or a timer.
Input and output bindings are mechanisms that allow you to connect to resources, such as a CosmosDB data store or a queue. You can use return statements to put data into the queue, as defined in the output binding attribute.
Unit Tests
Unit tests are a crucial part of the build process for API and Function Apps.
The build process is where unit tests should be run, specifically targeting classes that contain function triggers and business logic. Ideally, you're unit testing the classes that contain the function triggers, along with any other classes that contain business logic.
Writing unit tests for a class that contains purely business logic is just like you'd do elsewhere in .NET. On the other hand, until recently, it wasn't easy to test the function trigger classes.
There are no restrictions from a test runner perspective, so whether you prefer MsTest, nUnit, or xUnit, you're all set.
API
Azure Functions API is a crucial part of building scalable and efficient applications. It's a deployable unit that needs to be invoked, and that's where triggers come in - the event that causes a single function to run.
A trigger is configured by a binding, and there are several trigger types available, covering common scenarios. Each function in a function app has its own trigger, making it easy to manage and monitor.
Input and output bindings are mechanisms that allow you to connect to resources, such as CosmosDB data stores or queues. This makes it easy to chain resources together in Azure.
The function's name is RunAsync, but using the FunctionName attribute makes it more friendly and easier to manage. This is especially useful when you have several different classes with a RunAsync function.
Using a return statement will put the data where it belongs, in this case, the queue named greetings-queue as defined in the output binding. This is a great way to handle data in Azure Functions.
When creating a function, you can try it out by choosing to run or debug it. This will execute the function locally, and you may need to configure some options in package.json.
Logic Apps
Logic Apps are a powerful tool for defining workflows that consume a range of APIs as connectors. These connectors can perform a series of actions defined in the workflow.
Azure Logic Apps can be triggered with APIs as connectors, and it can also have multiple triggers in a workflow. This flexibility makes it a great choice for complex workflows that require multiple inputs.
You can define a workflow in Azure Logic Apps using the Logic App designer, which allows you to easily connect to various APIs and services.
The monitoring capabilities of Azure Logic Apps include Log Analytics and Azure Monitor.
Here's a comparison of Azure Logic Apps and Azure Functions in a table format:
Deployment Process
The deployment process is where the magic happens, transforming your build artifact into a running application on Azure. This involves pushing the build artifact to Azure and verifying that everything is working as expected.
The deployment process can be broken down into several steps, some of which are straightforward, while others require a bit more thought. But having the right tool for the job makes all the difference.
You can manually deploy Function app artifacts to Azure using both the CLI and API. However, for production-grade work, it's highly recommended to use a well-known Continuous Deployment tool like Azure DevOps or Octopus Deploy.
Both Azure DevOps and Octopus Deploy have first-class support for Functions, giving you access to everything you need to deploy and configure your Function app. This includes the ability to create build and deployment pipelines with ease.
One of the neat shortcuts to creating your build and deployment pipelines with Azure DevOps is to use the Deployment Center option on the Platform features page. Here, you can tell Azure DevOps to create a Build Pipeline and Release Pipeline definition for you, provided your code lives on GitHub, Azure Repos, or BitBucket.
Comparison and Updates
Azure Functions 2.0 brings a lot of exciting updates to the table.
The new Functions quick start now allows you to get started with Azure Functions by selecting your programming language of choice.
One notable change is that the runtime is now built on .NET Core 2.1, which is a significant improvement over the previous version's .NET Framework support.
Deployment has also become easier, with the option to run code directly from a package.
Azure Functions 2.0 also introduces changes to .Net Function loading.
Tooling updates are available for Visual Studio, CLI, and VS Code, making it easier to develop and deploy Azure Functions.
A consumption-based SLA is now available, providing a more flexible and cost-effective option for users.
Here's a quick rundown of the key updates in Azure Functions 2.0:
- New Functions quick start by selected programming language
- Updated runtime built on .NET Core 2.1
- Deployment: Run code from a package
- .Net Function loading changes
- Tooling Update: Visual Studio, CLI and VS Code
- Consumption-based SLA
Management and Properties
You can manage your Azure assets, such as function apps and storage accounts, using the Azure Toolkit in Rider. This plugin offers a range of context-sensitive options for managing assets.
To deploy your Azure Functions, simply right-click in the Solution Window and choose Publish to Azure. You'll need to enter some basic information, like your subscription and storage options, resource groups, and hosting plans.
The Azure Portal is also available for managing cloud resources, and you can use a combination of Rider's Azure Explorer, the Azure CLI, and the Azure Portal to get the job done.
Manage Function Apps
You can manage function apps using Rider's Azure Explorer, which provides context-sensitive options for managing assets like function apps, storage accounts, and app services.
Right-clicking on the nodes in Azure Explorer reveals a range of management options, making it easy to navigate and manage your Azure resources.
The Azure Portal is also available online, offering an alternative way to manage cloud resources.
To deploy a function app, right-click in the Solution Window and choose Publish | Publish to Azure, then enter the required information for Azure, such as subscription and storage options.
You can also use the Azure Cloud Shell through Tools | Azure | Start Azure Cloud Shell for more flexibility in managing your Azure resources.
View Properties
Viewing the properties of your Azure Function App can be a crucial step in understanding its configuration and performance. You can view properties like App state, Region, Operating System, and Hosts.
To get a better grasp of your Azure Function App's properties, you can check its App state, which indicates its current status. This can be useful for troubleshooting or scaling issues.
The Region property shows where your Azure Function App is hosted, which is essential for understanding latency and data residency. This is especially important for applications that require low latency or strict data compliance.
Azure Function Apps can run on various Operating Systems, including Windows and Linux. This flexibility allows you to choose the best OS for your specific use case.
You can also view the properties of individual Azure Functions, including their type, direction, and methods. This can be helpful for understanding the functionality and behavior of each function.
Getting Started Guide
To get started with Azure Functions, you'll first need to choose a runtime stack, which determines the programming languages and frameworks you can use. This decision will impact the code you write and the tools you need to install.
Azure Functions supports multiple runtime stacks, including .NET Core, Node.js, Python, and Java.
You can create a new Azure Functions project using the Azure Functions Core Tools, which can be installed via npm or a package manager for your chosen runtime stack.
To create a new Azure Functions project, navigate to the Azure Functions Core Tools documentation to learn more about the command-line interface and how to use it to create a new project.
You'll also need to create a new Azure Functions project in Visual Studio or Visual Studio Code, depending on your preferred development environment.
Sources
- https://blog.jetbrains.com/dotnet/2020/10/29/build-serverless-apps-with-azure-functions/
- https://marcroussy.com/2019/08/15/building-deploying-azure-functions/
- https://azure.microsoft.com/en-us/products/functions
- https://turbo360.com/guide/azure-functions
- https://mohan-balaji.medium.com/getting-started-with-azure-functions-a-step-by-step-guide-e18f16764017
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