Azure functions host.json and function.json

 Azure functions host.json and function.json

Azure Functions is a serverless compute service that allows you to run code on-demand without the need to manage infrastructure. To configure the behavior of Azure Functions, you can use the host.json file. In this blog, we'll discuss what host.json is, how to use it, and its important features. 

What is host.json?

host.json is a configuration file for the Azure Functions host that defines the runtime behavior of your functions. It includes various configuration settings such as the function timeout, logging levels, default values for environment variables, and more.

Using host.json

To use host.json, you need to add it to the root of your function app directory. The file can contain various configuration settings that apply to all functions within the app, or it can contain settings specific to a particular function. If you have settings that apply to only one function, you can create a separate host.json file in the function's directory. 

host.json Settings

Here are some of the important settings that you can include in the host.json file: 

• version - Defines the version of the Azure Functions runtime that the function app should use.
• extensions - Allows you to enable or disable specific function extensions, such as the Azure Cosmos DB or Azure Event Hub extensions.
• logging - Allows you to configure the logging behavior of the function app, including the log level and the log destination.
• http - Allows you to configure HTTP-related settings, such as the default route prefix, the maximum request length, and more.
• durableTask - Allows you to configure settings for the Azure Durable Functions extension, such as the task hub name and the storage provider settings.
• functionTimeout - Defines the maximum time that a function can run before being terminated.
• environmentVariables - Allows you to define default values for environment variables that your functions use.

Conclusion

In conclusion, host.json is an important configuration file for Azure Functions that allows you to customize the behavior of your functions. It includes various settings that can be used to control the runtime behavior of your functions, such as the function timeout, logging behavior, and more. By understanding the different settings that you can include in host.json, you can configure your function app to meet your specific needs and optimize its performance.

What is function.json?

Function.json is a configuration file for individual functions in an Azure Function app that defines the input and output bindings, function trigger, and other function-specific settings. It provides a way to define the function signature, input and output types, and the way the function is triggered.

Using function.json

To use function.json, you need to add it to the function directory. The file contains various configuration settings that apply to the specific function. This file is used to define the input and output bindings, function trigger, and other function-specific settings.

function.json Settings

Here are some of the important settings that you can include in the function.json file: 

• bindings - Defines the input and output bindings for the function. This includes the type of binding, direction, name, and other specific properties.
• trigger - Defines the trigger for the function, such as an HTTP request, timer, or message queue.
• scriptFile - Defines the file that contains the function code.
• entryPoint - Defines the function entry point within the script file.
• disabled - Allows you to disable a specific function if it's no longer needed.
• name - The name of the function.
• direction - The direction of the binding, either "in" or "out". 

Conclusion

In conclusion, function.json is an important configuration file for individual functions in an Azure Function app that allows you to define the input and output bindings, function trigger, and other function-specific settings. By understanding the different settings that you can include in function.json, you can configure your function app to meet your specific needs and optimize its performance.