Failed to connect to the host via ssh: Host key verification failed - jenkins

Question

I am facing an issue while executing the ansible-playbook form Jenkins,
like :
PLAY [centos-slave-02] *********************************************************
TASK [Gathering Facts] *********************************************************
fatal: [centos-slave-02]: UNREACHABLE! => {"changed": false, "msg": "Failed to connect to the host via ssh: Host key verification failed.", "unreachable": true}
PLAY RECAP *********************************************************************
centos-slave-02 : ok=0 changed=0 unreachable=1 failed=0 skipped=0 rescued=0 ignored=0
but I am able to get ping-pong response and each time its asking for
Matching host key in /var/jenkins_home/.ssh/known_hosts:5 :
jenkins#c11582cb5024:~/jenkins-ansible$ ansible -i hosts -m ping centos-slave-02
Warning: the ECDSA host key for 'centos-slave-02' differs from the key for the IP address '172.19.0.3'
Offending key for IP in /var/jenkins_home/.ssh/known_hosts:2
Matching host key in /var/jenkins_home/.ssh/known_hosts:5
Are you sure you want to continue connecting (yes/no)? yes
centos-slave-02 | SUCCESS => {
"ansible_facts": {
"discovered_interpreter_python": "/usr/bin/python"
},
"changed": false,
"ping": "pong"
}
could anyone please fix this issue!thanks in advance.

Answer 1

Your known_hosts file in the jenkins-ansible host already has an entry for the host centos-slave-02. Now that the centos-slave-02 host's identity has changed, a new entry needs to be added. But the existing entry in the file is throwing this warning.
Warning: the ECDSA host key for 'centos-slave-02' differs from the key for the IP address '172.19.0.3'
Offending key for IP in /var/jenkins_home/.ssh/known_hosts:2
Matching host key in /var/jenkins_home/.ssh/known_hosts:5
You can either manually edit the /var/jenkins_home/.ssh/known_hosts file to remove the key for this centos-slave-02 host or run the below command,
ssh-keygen -R centos-slave-02
The workaround with ansible would be to add this line in ansible.cfg under [defaults] section,
[defaults]
host_key_checking = False
This will disable HostKeyChecking when making SSH connections.

Answer 2

Make sure you don't use sudo in your jenkin build Exec command.