Serverless Data API with Azure Functions

A short example that demonstrates how to use Azure Functions and Azure Blob Storage to build a serverless data sharing API. The sample uses a HTTP Trigger and Blob storage input binding, to return data from a file over HTTP.

Instructions for use

1. Ensure you have the pre-requisite tools and extensions for Azure Functions development (VS Code, the Azure Functions Extension, and Azure Functions Core Tools are recommended - you can find more details on getting started here)
2. Clone this repo to your local machine using git clone ..
3. cd into the folder, and launch VS code with code .
4. Create a local.settings.json file with the following structure. Update the MyStorageConnectionAppSetting with the connection string to your storage account that you would like to share data from.

{
  "IsEncrypted": false,
  "Values": {
    "AzureWebJobsStorage": "",
    "FUNCTIONS_WORKER_RUNTIME": "python",
    "MyStorageConnectionAppSetting": "$STORAGE_CONNECTION_STRING"
  }
}

1. In your storage account, create a storage container called data, add a folder, and a file within that folder, e.g. /curated/data.txt. If you want to point the function at an existing container, you can update this in the path value of the inputblob binding in the function.json file.

Local emulation

1. Run the function locally by running func start, or starting debug mode in VS Code (Run > Start Debugging, or press F5)
2. Retrieve data by heading to the url in your browser, or issuing a curl request against the endpoint, e.g.

curl http://localhost:7071/api/data/curated/data.txt

Running in Azure Functions on Azure

Details on how to package and deploy your function can be found in the documentation

Limitations

• NB: This example function does not include any authentication mechanism - deploying as-is, with a connection your storage account is not advised (unless of course this is what you are attempting to achieve!) as it is creating a publically callable endpoint into your storage account. If the data in your storage account is sensitive in nature, do not do this.
• This function returns a 404 error if the folder or file does not exist. It would be great to instead return a list of available files within the folder for download.