"401 Unauthorized Error" due to DNS resolution failure when accessing Aria Operations Plugin in vCenter

Products

• VCF Operations/Automation (formerly VMware Aria Suite)

Issue/Introduction

After registering Aria Operations with vCenter you may see the following message when you access VMware Aria Operations remote plugin from vCenter:

401 Unauthorized Error : Unable to authorize VMware Aria Operations/vCenter Server API with the provided credentials

Please refer the below mentioned steps to resolve

• Ensure that the logged-in user account has enough privilege - i.e permissions to access MOB
• Ensure that the vCenter Adapter Instance in VMware Aria Operations is configured for the current vCenter and in collecting state.
• Ensure that all the vCenter Adapter Instances in VMware Aria Operations is in collecting state.

 

You may see the following error in /storage/log/vcops/log/unicorn.log:

2024-09-06 12:55:09.657  INFO 973594 --- [ajp-nio-127.0.0.1-8010-exec-10] c.v.v.u.security.SessionServiceImpl      : Obtaining new session for provided IP
2024-09-06 12:55:09.661 ERROR 973594 --- [ajp-nio-127.0.0.1-8010-exec-10] c.v.v.u.security.SessionServiceImpl      : Failed to Create :

org.springframework.web.client.ResourceAccessException: I/O error on POST request for "https://vcenter.example.com/api/ui/vcenter/session/clone-ticket": vcenter.example.com: Temporary failure in name resolution; nested exception is java.net.UnknownHostException:
 vcenter.example.com: Temporary failure in name resolution
        at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:791) ~[spring-web-5.3.31.jar:5.3.31]
        at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:717) ~[spring-web-5.3.31.jar:5.3.31]
        at org.springframework.web.client.RestTemplate.exchange(RestTemplate.java:608) ~[spring-web-5.3.31.jar:5.3.31]

Environment

VMware Aria Operations 8.x
VMware vCenter 8.0.0.10000 and later

Cause

The plugin requires permission to log in to Aria Operations via vCenter user.

Other causes:

• "401 Unauthorized Error" due to insufficient permissions when accessing Aria Operations Plugin in vCenter

Resolution

Ensure that DNS resolution is working properly on Aria operations. If Operations node is not able to perform nslookup against vCenter IP/FQDN, the plugin registration will be incomplete.

Example nslookup output:

root@localhost [ ~ ]# nslookup vcenter.example.com
Server:         192.168.1.1
Address:        192.168.1.1#53

Name:   vcenter.example.com
Address: 192.168.1.10

root@localhost [ ~ ]# nslookup 192.168.1.10
10.1.168.192.in-addr.arpa     name = vcenter.example.com

 

 Note: Ensure that both forward and reverse DNS lookup resolves IP and FQDN as per example above, including the short name.

Additional Information

This may affect the Aria Operations Remote Plugin that is used in vCenter 8.0.0.10000 or later. 

For more information on the Remote Plugin, see Integrating the Aria Operations plugin with vCenter Server