How to connect Azure ARO private cluster?

Question

How to connect Azure ARO private cluster?

Saravanan Krishnan 40

I have created Private ARO (Azure Redhat Openshift) cluster and peered between the hub and vnet where cluster created. But still I could not able to connect the cluster from the jump host which created in hub vnet.

When I connect the cluter from jump host below is the error message.

aro@kcns-jump-host:~$ oc login $apiServer -u kubeadmin -p XXXXXXXXX

error: dial tcp: lookup api.kcns.in on 127.0.0.53:53: no such host - verify you have provided the correct host and port and that the server is currently running.

aro@kcns-jump-host:~$ echo $apiServer

https://api.kcns.in:6443/

aro@kcns-jump-host:~$

Prrudram-MSFT 28,156 Reputation points

2024-04-29T08:26:50.8+00:00
@Saravanan Krishnan

It seems that the error message is related to the DNS resolution. The error message "no such host" indicates that the DNS server is not able to resolve the hostname "api.kcns.in".

To resolve this issue, you can try the following steps:

Check if the DNS server is configured correctly on the jump host. You can check the DNS configuration by looking at the /etc/resolv.conf file. This command will display the DNS server IP addresses configured on the jump host. Make sure that the DNS server IP address is correct and reachable.

Check if the DNS server is able to resolve the hostname "api.kcns.in". You can check this by running the following command:
nslookup api.kcns.in
This command will display the IP address of the hostname "api.kcns.in". If the DNS server is not able to resolve the hostname, you can try to add the hostname and IP address mapping to the "/etc/hosts" file on the jump host.

Check Firewall Rules: Ensure that there are no firewall rules blocking the connection to the API server on port 6443.
If the above steps do not work, you can try to use the IP address of the API server instead of the hostname.

Please let me know if this helps.

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Prrudram-MSFT 28,156 Reputation points

2024-04-29T08:26:50.8+00:00

@Saravanan Krishnan

It seems that the error message is related to the DNS resolution. The error message "no such host" indicates that the DNS server is not able to resolve the hostname "api.kcns.in".

To resolve this issue, you can try the following steps:

Check if the DNS server is configured correctly on the jump host. You can check the DNS configuration by looking at the /etc/resolv.conf file. This command will display the DNS server IP addresses configured on the jump host. Make sure that the DNS server IP address is correct and reachable.

Check if the DNS server is able to resolve the hostname "api.kcns.in". You can check this by running the following command:
nslookup api.kcns.in
This command will display the IP address of the hostname "api.kcns.in". If the DNS server is not able to resolve the hostname, you can try to add the hostname and IP address mapping to the "/etc/hosts" file on the jump host.

Check Firewall Rules: Ensure that there are no firewall rules blocking the connection to the API server on port 6443.
If the above steps do not work, you can try to use the IP address of the API server instead of the hostname.

Please let me know if this helps.

Answer 1

Hello Saravanan Krishnan

Could you please tell me if you have full access from tje JumpHost server?

From the Jump host what is the output of both commands below?

nslookup URL_of_aro_cluster_console/api

and

dig URL_of_aro_cluster_console/api

After you performed the az login and credentials setup

you are able to list the cluster?

# List ARO Clusters :

az aro list -o table

Also you can check the aro cluster information and try using kubeadmin as following:

# Get Kubeadmin Access :

az aro list-credentials --name $AROCluster --resource-group $ARORG


kubeadminPassword=$(az aro list-credentials --name $AROCluster --resource-group $ARORG --query=kubeadminPassword -o tsv)

kubeadminUsername=$(az aro list-credentials --name $AROCluster --resource-group $ARORG --query=kubeadminUsername -o tsv)

AROAPISrvURL=$(az aro show -g $ARORG -n $AROCluster --query apiserverProfile.url -o tsv)

oc login $AROAPISrvURL -u $kubeadminUsername -p $kubeadminPassword

Let me know if this information was helpful, and upvote

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How to connect Azure ARO private cluster?

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