Last time, we were trying to reinstall the undercloud so that it used a different IP block. The reinstall succeeded, but now the two Ironic nodes that would normally be provisioned as a compute node and a control node are in a very strange state.

The problem: both nodes have the power state ‘None’. Aside from it being very odd, this also means that we can’t do anything with the nodes as-is. The power state ‘None’ is a bit trickier to debug than the other ‘wrong’ states. There are some tips to help in debugging Ironic problems.

Run ironic node-list. You want the baremetal nodes to be in the following states: Power State == Off, Provisioning State == available, and Maintenance == False.

Maintenance mode

Nova will not schedule Ironic nodes that are in maintenance mode. If we want to be able to schedule a node in maintenance mode, we have to set it to some other state that Ironic will allow.

It is important to note that in any given state there will be state changes that are not allowed. See this state machine diagram for more information: 'state machine diagram' Image source

For example, the only operation an Ironic node in a deploy failed state will complete is deleted. So, if you want to get your node to the ‘Available’ state, first set its state to be deleted. From there, clean it; after the clean operation completes, the node will be available.

You will want to do something like:

ironic node-set-provision-state <node_uuid> manage

How to set Ironic Provisioning State

Orphaned nodes

You may also have orphaned Ironic nodes, where the node is available, but still has an instance_uuid assigned to it. To check if the node is available, run nova list and heat stack-list. If the stack is deleted and Nova does not show any servers up and running, then the baremetal node is still available.

This is something that Nova should do upon deletion, but in the case it failed to, clear the instance_uuid the node is holding onto by running

ironic node-update <node_uuid> remove instance_uuid

Note: don’t do what I did. Do not substitute the actual instance_uuid in.

Incorrect SSH credentials

You might be trying to do some operation upon Ironic nodes, but coming across the error message.

Failed to validate power driver interface. Can not delete instance. Error: SSH connection
cannot be established: Failed to establish SSH connection to host (HTTP 500)

To see which parameters are missing, run ironic node-validate <node>. You might see something like this:

$ ironic node-validate 94066ef2-8604-4041-962b-d68ccc5fdf4a  
| Interface  | Result | Reason                                                                                         |  
| boot       | True   |                                                                                                |  
| console    | False  | Missing 'ssh_terminal_port' parameter in node's 'driver_info'                                  |  
| deploy     | True   |                                                                                                |  
| inspect    | True   |                                                                                                |  
| management | True   |                                                                                                |  
| power      | False  | SSH connection cannot be established: Failed to establish SSH connection to host |  
| raid       | True   |                                                                                                |  

The provided SSH credentials are incorrect.

This is the part that Juan Antonio Osorio Robles (@jaosorior on IRC) worked on, but apparently it seemed that our system did not have the right credentials.

The steps he took to fix it were: 1. Added the undercloud public key to the authorized keys of the host server 2. Added the private key of the undercloud to Ironic. For each node do something like:

ironic node-update <node_uuid> add driver_info/ssh_key_contents="$(cat .ssh/id_rsa)"

With this in place, we were finally able to complete the operations we wanted to do.