No events on a fresh new installation

I did a fresh new Sentry Onpremise installation (Centos 7) and I can access web interface, but it’s not catching events.

I didn’t change anything in the installation, I just ran ./install.sh

When I look at Nginx container, it’s receiving all requests normally:

10.47.16.212 - - [08/Mar/2021:21:05:51 +0000] "POST /api/2/store/ HTTP/1.1" 200 41 "-" "sentry.php/3.2.0" "-"
10.47.16.212 - - [08/Mar/2021:21:12:45 +0000] "POST /api/2/store/ HTTP/1.1" 200 41 "-" "sentry.php/3.2.0" "-"

But looking at Relay container, I see this errors:

2021-03-08T21:29:11Z [relay_server::actors::upstream] WARN: Network outage, scheduling another check in 60s
2021-03-08T21:30:02Z [relay_server::actors::upstream] ERROR: authentication encountered error: could not send request to upstream
caused by: could not send request using reqwest
caused by: error sending request for url (http://web:9000/api/0/relays/register/challenge/): error trying to connect: operation timed out

Anyone know what might be happening?

This means relay cannot talk to the web service (which is the Sentry backend). I’ve seen a bunch of posts from folks using CentOS similar to this and they all seemed to be resolved with a DNS or firewall setting change.