danielniccoli / AzureFunctionsWithLitestarAndPydanticSample

This serves as a sample demonstrating the integration of LiteStar and Pydantic into Azure Functions.

Azure Functions with LiteStar and Pydantic integration

This serves as a sample demonstrating the integration of LiteStar and Pydantic into Azure Functions.

LiteStar includes built-in Pydantic support, offering features such as OpenAPI support with Swagger UI and ReDoc UI, as well as data validation using Pydantic, which incorporates JSON schema and provides JSON schema validation.

Installation

1. Clone this repository
2. Create a Python 3.11 venv at ./.venv

Sample HTTP Requests

The following PowerShell snippet sends a valid request to the API. LiteStar will parse and validate the JSON content in the body against the JSON schema of the Pydantic model.

$paramsSuccess = @{
    Method = "POST"
    Uri = "http://localhost:7071/securitygroup"
    Headers = @{
        "X-MS-CLIENT-PRINCIPAL-NAME"="[e-mail]"
        "X-MS-CLIENT-PRINCIPAL-ID"="eb2f63e0-6344-4bf3-b19b-274fec760547"
    }
    ContentType = "application/json"
    Body = @{
        "owner"="[e-mail]"
        "deputy"="ffa69a95-0c0f-4ecf-9d1b-28071a742010"
        "displayName"="Finance Team"
        "description"="Employees working in the finance department."
        "mailEnabled"=$true
    } | ConvertTo-Json

}
Invoke-RestMethod @paramsSuccess

The following PowerShell snippet sends an invalid request to the API. LiteStar will parse and validate the JSON content in the body against the JSON schema of the Pydantic model. The model and consequently the JSON schema requires the properties owner and deputy, which are missing in the request.

$paramsFails = @{
    Method = "POST"
    Uri = "http://localhost:7071/securitygroup"
    Headers = @{
        "X-MS-CLIENT-PRINCIPAL-NAME"="[e-mail]"
        "X-MS-CLIENT-PRINCIPAL-ID"="eb2f63e0-6344-4bf3-b19b-274fec760547"
    }
    ContentType = "application/json"
    Body = @{
        "displayName"="Finance Team"
        "description"="Employees working in the finance department."
        "mailEnabled"=$true
    } | ConvertTo-Json

}
Invoke-RestMethod @paramsFails

Once sent, the API returns the following error message:

{
    "status_code": 400,
    "detail": "Validation failed for POST https://localhost:7071/securitygroup",
    "extra": [
        {"message": "Field required", "key": "owner"},
        {"message": "Field required", "key": "deputy"}
    ]
}

💡 You can also check out the automatically generated OpenAPI-based documentation at:

• http://localhost:7071/schema (for ReDoc),
• http://localhost:7071/schema/swagger (for Swagger UI),
• http://localhost:7071/schema/elements (for Stoplight Elements),
• http://localhost:7071/schema/rapidoc (for RapiDoc),

Notes

The properties of this sample's Pydantic model SecurityGroupRequest adhere to Python's snake case convention. When serializing, Pydantic translates property names directly into JSON on a one-to-one basis. For this sample, we want Pydantic to convert property names to camel case. We can achieve this by passing by_alias=True. Since LiteStar handles this behavior, we must instead configure the Pydantic plugin with prefer_alias=True as shown below:

pydantic_plugin = PydanticPlugin(prefer_alias=True)
litestar_app = Litestar([securitygroup_post], plugins=[pydantic_plugin])

If the property names should be passed "as-is", then this would suffice:

litestar_app = Litestar([securitygroup_post])