Fix clear cache to clear valkey instead of filesystem cache

[kalilsn]

Issue(s) Resolved

Resolves #1233

High-level Explanation of PR

After #1131 we no longer cache data on the filesystem, and instead store it in redis. In both local development and in the sandbox deployments, we regularly run the reset command, which also attempts to clear the cache. Since that cache-clearing function wasn't working, we could end up with stale data in the sandbox cache.

Test Plan

It's easiest to see this clear the cache if you install redis-cli (or some kind of gui redis app). redis-cli monitor will let you see commands as they come in, and redis cli scan 100 will print 100 keys so you can see if there's data in the cache.

• With the valkey cache running (pnpm -w dev:cache:start) and after using the app a bit, run redis cli scan 100 to show there's data in the cache
• Optionally, run redis-cli monitor in a separate terminal
• Run pnpm clear-cache
• Scan again and see that the cache is clear + observe the flushall command sent in the monitor window

To actually recreate the initial sandbox bug requires a bit more effort, since you need to check out a previous commit (1c21713d4321f728ee4b6362f2b63675542868c1) and run reset.

I've also confirmed that this reset succeeds on lightsail by sshing into the preview instance for this branch and confirming that the migrations container exits with status 0 and that you can see the cache clearing command run in the logs for that container.

Notes

I don't think this is an issue in prod. My guess is the reason we're seeing strange behavior is that the seed scripts have a mixture of hardcoded and generated data, so we end up with some cache hits to stale data after reset. But that doesn't entirely make sense, so lmk if you have other ideas.

[tefkah]

Seems to work! No clue what's happening in the preview env tho

[kalilsn]

No clue what's happening in the preview env tho

Failing to load env vars :(. dotenv doesn't put env vars in the environment so I was using source. but source throws an error if the passed file doesn't exist (.env.local), so I would have needed some pretty ugly conditionals to make that version work everywhere.

[tefkah]

my guess is that that will also not work, could you not do echo 'FLUSHALL' | dotenv -e .... -- nc ...?

[tefkah]

if that also doesn't work i'd just write a separate script 😅

[kalilsn]

I think what I have now should work. I'm using dotenv ... -p VALKEY_HOST which just prints out the specific var I'm trying to use.

echo 'FLUSHALL' | dotenv -e .... -- nc ... doesn't actually set environment variables, it populates process.env. So only a node script will actually be able to access those (not nc).