How to host and share Data Docs on GCS¶
This guide will explain how to host and share Data Docs on Google Cloud Storage. We recommend using IP-based access, which is achieved by deploying a simple Google App Engine app. Data Docs can also be served on Google Cloud Storage if the contents of the bucket are set to be publicly readable, but this is strongly discouraged.
Prerequisites: This how-to guide assumes you have already:
Set up a working deployment of Great Expectations
Installed and initialized the Google Cloud SDK (in order to use the gcloud CLI)
Have permissions to: list and create buckets, deploy Google App Engine apps, add app firewall rules
Steps
Create a Google Cloud Storage bucket using gsutil.
Make sure you modify the project name, bucket name, and region for your situation.
> gsutil mb -p my_org_project -l US-EAST1 -b on gs://my_org_data_docs/ Creating gs://my_org_data_docs/...
Create a directory for your Google App Engine app and add the following files.
We recommend placing it in your project directory, for examplegreat_expectations/team_gcs_app
.app.yaml (make sure to use your own bucket name)¶
1 2 3 runtime: python37 env_variables: CLOUD_STORAGE_BUCKET: my_org_data_docsrequirements.txt¶
1 2 flask>=1.1.0 google-cloud-storagemain.py¶
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 import logging import os from flask import Flask, request from google.cloud import storage app = Flask(__name__) # Configure this environment variable via app.yaml CLOUD_STORAGE_BUCKET = os.environ['CLOUD_STORAGE_BUCKET'] @app.route('/', defaults={'path': 'index.html'}) @app.route('/<path:path>') def index(path): gcs = storage.Client() bucket = gcs.get_bucket(CLOUD_STORAGE_BUCKET) try: blob = bucket.get_blob(path) content = blob.download_as_string() if blob.content_encoding: resource = content.decode(blob.content_encoding) else: resource = content except Exception as e: logging.exception("couldn't get blob") resource = "<p></p>" return resource @app.errorhandler(500) def server_error(e): logging.exception('An error occurred during a request.') return """ An internal error occurred: <pre>{}</pre> See logs for full stacktrace. """.format(e), 500
If you haven’t done so already, authenticate the gcloud CLI and set the project.
Insert the appropriate project name.¶> gcloud auth login && gcloud config set project <<project_name>>
Deploy your Google App Engine app.
Issue the following CLI command from within the app directory created above:
gcloud app deploy
.
Set up Google App Engine firewall for your app to control access.
Visit the following page for instructions on creating firewall rules: Creating firewall rules
Add a new GCS site to the data_docs_sites section of your great_expectations.yml.
You may also replace the default
local_site
if you would only like to maintain a single GCS Data Docs site.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 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 gs_site: # this is a user-selected name - you may select your own class_name: SiteBuilder store_backend: class_name: TupleGCSStoreBackend project: my_org_project # UPDATE the project name with your own bucket: my_org_data_docs # UPDATE the bucket name here to match the bucket you configured above site_index_builder: class_name: DefaultSiteIndexBuilder
Build the GCS Data Docs site.
Use the following CLI command:
great_expectations docs build --site-name gs_site
. If successful, the CLI will provide the object URL of the index page. Since the bucket is not public, this URL will be inaccessible. Rather, you will access the Data Docs site using the App Engine app configured above.> great_expectations docs build --site-name gs_site The following Data Docs sites will be built: - gs_site: https://storage.googleapis.com/my_org_data_docs/index.html Would you like to proceed? [Y/n]: Y Building Data Docs... Done building Data Docs
Test that everything was configured properly by launching your App Engine app.
Issue the following CLI command:
gcloud app browse
. If successful, the gcloud CLI will provide the URL to your app and launch it in a new browser window. The page displayed should be the index page of your Data Docs site.
Additional resources