@ramirogm I just did some more digging and found this thread. I checked the logs on the host OS and found:
# journalctl --no-pager
e874ef2 balenad[1236]: time="2022-12-08T16:42:38.781516230Z" level=error msg="[resolver] error writing resolver resp, dns: bad rdata"
To further verify that the container name length is involved I deployed a third test container with an extra long name. This container is identical to the other two test containers except for the name and I can reproduce the issue.
Looking into the container names, it seems that the naming schema has been changed in Balena in some update between 2.68 and 2.89. See the two screenshots below.
Balena OS 2.101.11, long names.
Balena OS 2.68.1, short names.
I’m not sure if that’s the root cause or a symptom. I’m a bit surprised that this apparently doesn’t cause any issues in other setups, since network communication between containers is a very common thing. Can you confirm that and do you maybe have some insights into the changes made and a possible solution.