Google Cloud Platform Strava webhook

This repository is designed to be deployed to a Cloud Function in Google Cloud Platform. It should a publicly visible endpoint which is called by Strava whenever an activity is added or changed to which you are subscribed.

The function handles two situations:

1. Initialisation
2. Message receipt, which is relayed to Pub/Sub on GCP.

This repo is one of four in an example module of how to load Strava data to Google BigQuery.

Initialisation

You should deploy this to a Cloud Function first, as you need to validate the endpoint URL to Strava. When deploying, you need to specify a random string as an environment variable VERIFY_TOKEN.

For an example of deploying using Terraform, please see my Terraform repo.

When deployed, you need to create a subscription. These instructions are simplified from the Strava API Documentation. You need a callback_url (the URL from the Cloud Function Trigger page) (e.g. https://region-project-id.cloudfunctions.net/strava-webhook), and your Strava API client_id and client_secret, both of which are on the Strava API page. To create the subscription, create a POST call to the end point as below, substituting your client_id, client_secret, callback_url, and verify_token which you should have put in Secret Manager.

curl -X POST https://www.strava.com/api/v3/push_subscriptions \
      -F client_id=5 \
      -F client_secret=7b2946535949ae70f015d696d8ac602830ece412 \
      -F 'callback_url=http://a-valid.com/url' \
      -F 'verify_token=STRAVA'

This call should trigger Strava to call your endpoint, and will handle receipt of the returned message, all whilst you wait for a response to this POST request. When successful, Strava will reply with your subscription_id, which you should then manually add as a version to Secret Manager for a secret called STRAVA_SUBSCRIPTION_ID.

Your webhook and subscription should then be available, but next you need to authorise your user against the client. This is covered in my Pull Cloud Function.

Environment Variables

This Cloud Function requires the following environment variables:

Environment Variable Name	Explanation
GOOGLE_APPLICATION_CREDENTIALS	A path to a JSON credentials file. Within GCP this is set automatically.
GCP_PROJECT	The Project Id in which specifically the Secret Manager secrets are stored. Within GCP this is set automatically.
VERIFY_TOKEN	A random string used to confirm the subscription. You need to provide this because you are going to trigger the subscription process manually.