Sending text messages (SMS) is silently failing on vector.im

[babolivier]

All look good in the logs:

Oct  5 10:14:15 corus sydent-vectoris[16661]: 2021-10-05 10:14:15,659 - sydent.validators.msisdnvalidator - 126 - INFO - Attempting to text code [...] to 44[my phone number] (country 44) with originator {'type': 'alpha', 'text': 'Element'}
Oct  5 10:14:15 corus sydent-vectoris[16661]: 2021-10-05 10:14:15,659 - twisted - 147 - INFO - "::ffff:10.101.0.14" - - [05/Oct/2021:10:14:14 +0000] "POST /_matrix/identity/api/v1/validate/msisdn/requestToken HTTP/1.1" 200 94 "-" "Synapse/1.44.0rc2 (b=matrix-org-hotfixes,ebbd37b66)"

But no text message is ever received.

Not sure whether this is due to #410 or if there's an issue with the OpenMarket API causing it to silently fail sending the text message.

A good first step would be fixing #410 so we can tell if the OM API responds with an error.

[callahad]

Could also be good to log event IDs so we can check status: https://www.openmarket.com/docs/Content/apis/v4http/get-status-json.htm

[babolivier]

I've released Sydent v2.4.4 which builds on top of v2.4.3 with #412 in addition to it. I've asked ops to deploy this new version onto vector.im, and when that'll be done we should be able to retrieve enough information from the Sydent logs to understand why this is happening.

[babolivier]

The main cause was #413: sendSMS got converted from inline callbacks into async/await in v2.4.0, and was used in a "fire and forget" sort of way. Except that doesn't work with async/await, so the function was never run. It's unclear why Sydent was never warning about this until we deployed #412, so we'll need to look into this.
However, now that #413 is merged, as well as #415 (which then revealed an issue that would respond with an error despite the request succeeding because we weren't using Twisted's structures correctly), SMS sending works as expected.