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How to host and share Data Docs on Azure Blob Storage

This guide will explain how to host and share Data DocsHuman readable documentation generated from Great Expectations metadata detailing Expectations, Validation Results, etc. on Azure Blob Storage. Data Docs will be served using an Azure Blob Storage static website with restricted access.

Prerequisites: This how-to guide assumes you have:
## Steps

1. Create an Azure Blob Storage static website

  • Create a storage account.
  • In settings select Static website to display the configuration page for static websites.
  • Select Enabled to enable static website hosting for the storage account.
  • Write "index.html" in Index document.

Note the Primary endpoint url. Your team will be able to consult your data doc on this url when you have finished this tutorial. You could also map a custom domain to this endpoint. A container called $web should have been created in your storage account.

2. Configure the config_variables.yml file with your Azure Storage credentials

Get the Connection string of the storage account you have just created.

We recommend that Azure Storage credentials be stored in the config_variables.yml file, which is located in the uncommitted/ folder by default, and is not part of source control. The following lines add Azure Storage credentials under the key AZURE_STORAGE_CONNECTION_STRING. Additional options for configuring the config_variables.yml file or additional environment variables can be found here.

AZURE_STORAGE_CONNECTION_STRING: "DefaultEndpointsProtocol=https;EndpointSuffix=core.windows.net;AccountName=<YOUR-STORAGE-ACCOUNT-NAME>;AccountKey=<YOUR-STORAGE-ACCOUNT-KEY==>"

3. Add a new Azure site to the data_docs_sites section of your great_expectations.yml

data_docs_sites:
local_site:
class_name: SiteBuilder
show_how_to_buttons: true
store_backend:
class_name: TupleFilesystemStoreBackend
base_directory: uncommitted/data_docs/local_site/
site_index_builder:
class_name: DefaultSiteIndexBuilder
az_site: # this is a user-selected name - you may select your own
class_name: SiteBuilder
store_backend:
class_name: TupleAzureBlobStoreBackend
container: \$web
connection_string: ${AZURE_STORAGE_CONNECTION_STRING}
site_index_builder:
class_name: DefaultSiteIndexBuilder

You may also replace the default local_site if you would only like to maintain a single Azure Data Docs site.

note

Since the container is called $web, if we simply set container: $web in great_expectations.yml then Great Expectations would unsuccessfully try to find the variable called web in config_variables.yml. We use an escape char \ before the $ so the substitute_config_variable method will allow us to reach the $web container.

You also may configure Great Expectations to store your ExpectationsA verifiable assertion about data. and Validation ResultsGenerated when data is Validated against an Expectation or Expectation Suite. in this Azure Storage account. You can follow the documentation from the guides for Expectations and Validation Results but be sure you set container: \$web in place of the other container name.

The following options are available for this backend:

  • container: The name of the Azure Blob container to store your data in.
  • connection_string: The Azure Storage connection string. This can also be supplied by setting the AZURE_STORAGE_CONNECTION_STRING environment variable.
  • prefix: All paths on blob storage will be prefixed with this string.
  • account_url: The URL to the blob storage account. Any other entities included in the URL path (e.g. container or blob) will be discarded. This URL can be optionally authenticated with a SAS token. This can only be used if you don't configure the connection_string. You can also configure this by setting the AZURE_STORAGE_ACCOUNT_URL environment variable.

The most common authentication methods are supported:

  • SAS token authentication: append the SAS token to account_url or make sure it is set in the connection_string.
  • Account key authentication: include the account key in the connection_string.
  • When none of the above authentication methods are specified, the DefaultAzureCredential will be used which supports most common authentication methods. You still need to provide the account url either through the config file or environment variable.

4. Build the Azure Blob Data Docs site

You can create or modify an Expectation SuiteA collection of verifiable assertions about data. and this will build the Data Docs website. Or you can use the following CLICommand Line Interface command: great_expectations docs build --site-name az_site.

> great_expectations docs build --site-name az_site

The following Data Docs sites will be built:

- az_site: https://<your-storage-account>.blob.core.windows.net/$web/index.html

Would you like to proceed? [Y/n]: y

Building Data Docs...

Done building Data Docs

If successful, the CLI will provide the object URL of the index page. You may secure the access of your website using an IP filtering mechanism.

5. Limit the access to your company

  • On your Azure Storage Account Settings click on Networking
  • Allow access from Selected networks
  • You can add access to Virtual Network
  • You can add IP ranges to the firewall

More details are available here.