[ClusterLabs] [EXT] Fence Agents Format

[Windl, Ulrich]

Hi!

Some time ago, I had been asking for an improved fencing agent specification, because the existing documents made it impossible for me to write a fencing agent. I guess with such documentation, the questions below could have been answered as well...

Regards,
Ulrich

-----Original Message-----
From: Users <users-bounces at clusterlabs.org> On Behalf Of Or Raz
Sent: Monday, July 10, 2023 11:00 AM
To: users at clusterlabs.org
Subject: [EXT] [ClusterLabs] Fence Agents Format

Hi all,
My team has been working on a new operator which uses some of your Fence Agents (FA, i.e. fence_aws, fence_ipmilan, and etc.) to remediate an unhealthy Kubernetes node (see fence-agents-remediation <https://github.com/medik8s/fence-agents-remediation> ).
After looking on the recommended attributes for new FAs <https://github.com/ClusterLabs/fence-agents/blob/main/doc/FenceAgentAPI.md#attribute-specifications> , and the valid action attribute values <https://github.com/ClusterLabs/fence-agents/blob/main/doc/FenceAgentAPI.md#agent-operations-and-return-values> , 
I have some questions on the structure/format of the FAs command attributes and their responses:

1.	Will running a fence-agent without mentioning the action field will always choose the reboot option (e.g. the following call will reboot the node "fence_aws --access-key ACCESS_KEY --secret-key SECRET_KEY --plug i-INSTANCE_ID --region AWS_REGION")?
2.	Are there any must-have fields which are shared between all the FAs that you support? I assume the answer is no, since I didn't see any must fields which are mutual between fence_aws, and fence_ipmilan for instance. A must field is a field which is required for running the FA (e.g. access-key for fence_aws).
3.	Do the result responses to the FA are identical per action? E.g. For the reboot action, I have seen that on success I always receive `Success: Rebooted` for fence_aws, and fence_ipmilan. I am an uncertain whether that is correct for all the FAs.

Best regards,

OR