Google Cloud Storage OAuth backend

[ccaruceru]

Summary

Add Google Cloud Storage (GCS) support for OAuth installation and state stores, as a follow up from slackapi/bolt-python#962 (comment).
(ported from ccaruceru/slack-multireact/multi_reaction_add/oauth)

Testing

• create/reuse a slack app and install it in a workspace
• use Bolt to write a small app to ask the user for some permissions on app installation, in conjunction with the newly added GCS storage
  e.g.

from google.cloud.storage import Client
from slack_bolt import App
from slack_bolt.oauth.oauth_settings import OAuthSettings
from slack_sdk.oauth.state_store.google_cloud_storage import GoogleCloudStorageOAuthStateStore
from slack_sdk.oauth.installation_store.google_cloud_storage import GoogleCloudStorageInstallationStore

bucket_name = "GOOGLE_BUCKET_NAME"
slack_client_id = "SLACK_CLIENT_ID"
slack_client_secret = "SLACK_CLIENT_SECRET"
slack_signing_secret = "SLACK_SIGNING_SECRET"

storage_client = Client()

app = App(
    signing_secret=slack_signing_secret,
    oauth_settings=OAuthSettings(
        install_page_rendering_enabled=False,
        client_id=slack_client_id,
        client_secret=slack_client_secret,
        scopes=[],  # scopes for bot operations
        user_scopes=["reactions:write"], # scopes for operations on behalf of user
        installation_store=GoogleCloudStorageInstallationStore(
            storage_client=storage_client,
            bucket_name=bucket_name,
            client_id=slack_client_id
        ),
        state_store=GoogleCloudStorageOAuthStateStore(
            storage_client=storage_client,
            bucket_name=bucket_name,
            expiration_seconds=600
        )
    )
)

@app.event("message")
def handle_message_events(event, client, context):
    """Listens for messages containing 'thumbs up' and reacts with a :thumbsup: emoji"""
    text = event.get("text", "").lower()
    channel = event.get("channel")
    timestamp = event.get("ts")
    if "thumbs up" in text:
        client.token = context.user_token
        client.reactions_add(
            channel=channel,
            name="thumbsup",
            timestamp=timestamp,
        )
        print("Added :thumbsup: reaction!")

• go to app's /slack/install page
  • observe a temporary oauth token is issued in the bucket
• finish the install flow
  • observe that the temporary token is gone
  • observe that bot* and installer* files are created
• interact with the newly added app (e.g. for the above app: add/invite the app to a public channel, type a message with "thumbs up" in it and see if the 👍 emoji is added to the message)
  • check that there are no errors in the app logs
  • check that the bot and installer files are unchanged

Category

• slack_sdk.web.WebClient (sync/async) (Web API client)
• slack_sdk.webhook.WebhookClient (sync/async) (Incoming Webhook, response_url sender)
• slack_sdk.socket_mode (Socket Mode client)
• slack_sdk.signature (Request Signature Verifier)
• slack_sdk.oauth (OAuth Flow Utilities)
• slack_sdk.models (UI component builders)
• slack_sdk.scim (SCIM API client)
• slack_sdk.audit_logs (Audit Logs API client)
• slack_sdk.rtm_v2 (RTM client)
• /docs (Documents)
• /tutorial (PythOnBoardingBot tutorial)
• tests/integration_tests (Automated tests for this library)

Requirements

• I've read and understood the Contributing Guidelines and have done my best effort to follow them.
• I've read and agree to the Code of Conduct.
• I've run python3 -m venv .venv && source .venv/bin/activate && ./scripts/run_validation.sh after making the changes.

[ccaruceru]

Since the time I wrote the original code, I saw there are a couple additions to the other installation stores (like the S3 one) compared to what I did, like historical data and more situations to handle when finding and deleting installs. Let me know what are your thoughts on the proposed changes and if we should tackle those too in this PR 🙂

[seratch]

Hi @ccaruceru, thanks for sending this pull request! As you can see here, all the existing built-in installation store implementations pass the same set of scenario tests. If we accept a new one, it must pass the same tests. I'm not sure if you have time or are willing to spend more time, but adding complete test assets to ensure the same quality would be appreciated.

[ccaruceru]

hi @seratch! I'll have a look at the tests this week and see if I can come up with something similar 👌🏻