"no query API server reachable" error with Thanos Ruler

[sunilnerella]

Thanos, Prometheus and Golang version used:

thanos, version 0.30.2 (branch: HEAD, revision: fe3f5d2)
build user: root@6213df2115a5
build date: 20230131-20:03:09
go version: go1.19.5
platform: linux/amd64

Object Storage Provider: S3

What happened:
I have setup Thanos with Prometheus on 3 Servers.

Server - 1 --> Prometheus + Sidecar + Store + Query
Server - 2 --> Prometheus + Sidecar + Store + Query
Server -3 --> Ruler 

Server-3 configuration of Ruler is managed to connect with Server1 and Server2 through the below command
/bin/thanos rule --data-dir /var/lib/prometheus-ruler/ --eval-interval 30s --rule-file /etc/prometheus/alert/*.yml --alert.query-url http:/<prom-server-1>:9090 --alertmanagers.url http://localhost:9093 --objstore.config-file /etc/prometheus/bucket.yml --query http://<prom-server-1>:129090 --query http://<prom-server-2>:29090 --label 'monitor_cluster="eu1"' --label 'replica="prom-server101"'

After the setup and command execution, we find "no query API server reachable" error in the UI of Thanos Ruler.

Can someone help on what might have gone wrong?

What you expected to happen:
The alerts in Thanos Ruler should work properly

How to reproduce it (as minimally and precisely as possible):

Full logs to relevant components:

Anything else we need to know:

[wotkddl21]

Any update from this issue?

[Aracki]

related to #5321