Storage limit - Framework to get users and record emails sent

[LeslieOA]

Overarching user needs:

• Users need to receive warning emails from about nearing (milestones) their storage quota or exceeding it. User gets an email notification from support@web3.storage when they’ve hit the following thresholds: 75%, 80%, 85%, 90%, with instructions on how to request more.
• Admins (support@web3.storage) need to receive an email when a user has gone over their allowed storage quota.

Notion - Enforcing-user-storage-capacity-limits

We can compare a users default (1TiB) or increased (user_tag table, tag of STORAGE_LIMIT_BYTES) storage quota to what their current used storage.

Tasks

1. DB function to retrieve all users with storage used with a percentage from/to range of their allocated storage quota
   User details returned:

• Email
• First and last name
• Storage quota
• Storage used

2. DB function to save details of sent email

• User ID
• Email type
• Email message ID
• Sent at

3. Node function in the cron package to call the DB functions to get the users that need emailing and save details of email sent.

4. Send the email with MailChimp. This is split out into a sub-ticket: Storage limit - Add MailChimp email service #1153

---

Threshold milestones and email frequency (TBC):

• Weekly email: equal to or greater than 75% of storage quota used (but below 85%)
• Weekly email: equal to or greater than 85% of storage quota used (but below 95%)
• Daily email: equal to or greater than 90% of storage quota used

Note: This quota includes both uploads via the web UI and pins via the PSA (Pinning Service API).

A cron job every {daily} (at a minimum).

MailChimp's API is the preferred method of email automation.

Questions

Do we need a storage_usage_exceeded table (as a snapshot of users who are over their quota) or will querying on cron and upload/pin suffice?

CC @dchoi27 for email frequency.

[dchoi27]

SGTM - I'd say crank it up to daily at 90% (and replace the last 2 bullets)

[adamalton]

I'm re-opening this, because #1273 is marked as fixing this, so as that is not yet closed, it makes sense for this to still be open. (Although it's slightly confusing, as both #1156 and #1273 are both marked as fixing this!)