azure-functions-libpostal

An Azure Function project which utilizes libpostal, a C library for parsing and normalizing street addresses. This can be useful for matching address strings with a database, and it can be used with Azure Cognitive Search to split an address over multiple index fields.

Due to C binding required for Libpostal, we need to create an Azure Function on Linux using a custom container. This will require a Premium plan or Dedicated (App Service) plan.

How to deploy

You can easily deploy this Azure Function in your own Azure environment, by clicking the Deploy to Azure button.

This will deploy an Azure Function app with a dedicated App Service plan (B3 sku) using the published Docker container on GitHub Container Registry. The project can easily be forked to make code changes and/or infrastructure changes.

Endpoints

/api/ParseAddress (GET/POST)

Input:

{
	"address": "Evert van de Beekstraat 354, 1118 CZ Schiphol, Nederland",
}

or

https://[APP_NAME].azurewebsites.net/api/ParseAddress?address=Evert%20van%20de%20Beekstraat%20354,%201118%20CZ%20Schiphol,%20Nederland

Output:

{
	"road": "evert van de beekstraat",
	"house_number": "354",
	"postcode": "1118cz",
	"city": "schiphol",
	"country": "nederland"
}

/api/ParseAddressCognitiveSearch (POST)

Input:

{
    "values": [
      {
        "recordId": "a1",
        "data":
           {
             "address": 
                "Evert van de Beekstraat 354, 1118 CZ Schiphol, Nederland "
           }
      },
      {
        "recordId": "b5",
        "data":
           {
             "address": 
                "One Microsoft Way, Redmond, WA 98052, United States"
           }
      },
      {
        "recordId": "c3",
        "data":
           {
             "address": null
           }
      }
    ]
}

Output:

{
    "values": [
        {
            "recordId": "a1",
            "data": {
                "road": "evert van de beekstraat",
                "house_number": "354",
                "postcode": "1118cz",
                "city": "schiphol",
                "country": "nederland"
            }
        },
        {
            "recordId": "b5",
            "data": {
                "house": "one",
                "road": "microsoft way",
                "city": "redmond",
                "state": "wa",
                "postcode": "98052",
                "country": "united states"
            }
        },
        {
            "recordId": "c3",
            "errors": [
                {
                    "message": "Could not complete operation for record."
                }
            ]
        }
    ]
}

Use with Cognitive Search

{
    "skills": [
      {
        "@odata.type": "#Microsoft.Skills.Custom.WebApiSkill",
        "name": "ParseAddressSkill",
        "description": "This skill calls an Azure Function binding to libpostal for fast international address parsing/normalization.",
        "uri": "https://[YOUR-DEPLOYED-FUNCTION].azurewebsites.net/api/ParseAddressCognitiveSearch",
        "context": "/document",
        "inputs": [
          {
            "name": "address",
            "source": "/document/address"
          }
        ],
        "outputs": [
		  {
            "name": "house",
            "targetName": "house"
          },
          {
            "name": "road",
            "targetName": "road"
          },
		  {
            "name": "house_number",
            "targetName": "house_number"
          },
		  {
            "name": "postcode",
            "targetName": "postcode"
          },
		  {
            "name": "city",
            "targetName": "city"
          },
		  {
            "name": "state",
            "targetName": "state"
          },
		  {
            "name": "country",
            "targetName": "country"
          }               
        ]
      }
  ]
}

Contribute to this repository

Project Structure

The main project folder (<project_root>) can contain the following files:

• local.settings.json - Used to store app settings and connection strings when running locally. This file doesn't get published to Azure. To learn more, see local.settings.file.
• requirements.txt - Contains the list of Python packages the system installs when publishing to Azure.
• host.json - Contains global configuration options that affect all functions in a function app. This file does get published to Azure. Not all options are supported when running locally. To learn more, see host.json.
• .vscode/ - (Optional) Contains store VSCode configuration. To learn more, see VSCode setting.
• .venv/ - (Optional) Contains a Python virtual environment used by local development.
• Dockerfile - (Optional) Used when publishing your project in a custom container.
• tests/ - (Optional) Contains the test cases of your function app. For more information, see Unit Testing.
• .funcignore - (Optional) Declares files that shouldn't get published to Azure. Usually, this file contains .vscode/ to ignore your editor setting, .venv/ to ignore local Python virtual environment, tests/ to ignore test cases, and local.settings.json to prevent local app settings being published.

Each function has its own code file and binding configuration file (function.json).

Developing your Python function using VS Code

This project includes a devcontainer that can be used on GitHub Codespaces or Visual Studio Code with Docker. During first build, it wil compile the Libpostal C module and download all training data. If you have not already, please checkout our quickstart to get you started with Azure Functions developments in Python.

Publishing your function app to Azure

For more information on deployment options for Azure Functions, please visit this guide.

License

MIT