[JENKINS-62340] ec2-1.50.3 doesn't clean known_hosts

When Jenkins is connected to the slaves in using the 'Connect by SSH Process' the slaves host key are not removed from the known_hosts  when the slave is deleted. 

It implies we will not be able to recreate a slaves with the same IPs which cause issues when Slaves are dynamically triggered. Currently i have to remove the SSH key verification to make it works.

---
Originally reported by angegar, imported from: ec2-1.50.3 doesn't clean known_hosts

• assignee: thoulen
  
• status: Open
  
• priority: Major
  
• component(s): ec2-plugin
  
• resolution: Unresolved
  
• votes: 0
  
• watchers: 1
  
• imported: 2025-12-06
  

Raw content of original issue

When Jenkins is connected to the slaves in using the 'Connect by SSH Process' the slaves host key are not removed from the known_hosts  when the slave is deleted. 


It implies we will not be able to recreate a slaves with the same IPs which cause issues when Slaves are dynamically triggered. Currently i have to remove the SSH key verification to make it works.

environment

```
Jenkins 2.236

Option : Connect by SSH Process = true
```

Start with the ec2-plugin path used by the “Connect by SSH Process” option and reproduce deletion of an agent whose host key is in known_hosts. Trace the agent deletion cleanup and verify that recreating an agent with the same IP succeeds with SSH host-key verification enabled; the issue names no files or tests.

Written by the indexing model from the issue text.