Upgrading from 1.21.3 to 1.24.15 results in 503 errors

[GAndreou97]

Hi all, apologies if this has been asked before, I have not been able to find an answer.

We are trying to upgrade an old RKE2 setup, we initially went from 1.21.3 to 1.22.17 without any issues.

However when trying to upgrade to 1.24.x, we are getting stuck with a load of 503 errors. We are using istio 1.16.5, with the same virtual services and gateway setup that was working on 1.21 and 1.22.

We can see the 503 errors in the instio ingressgateway pod, but there is no further information.

We've been looking at this for a while and are not sure how to proceed, any suggestions would be appreciated

[GAndreou97]

Just thought i'd leave the resolution here for anyone that comes across it.

The issue was actually caused by one of our network policies, seems like it wasn't causing an issue in 1.22.17 but was blocking communication in 1.23 onwards