ansible configuration

[Sakshi Jain]

So basically two users 

User1 , user2   user is a sudo user 

There are 5 servers : server1 , server2 , server3, server4, server5

We need password less connection from server1 to all other servers 

 I am facing issue with key password less authnetication

Tha playbook are be executed as sudo user that I have mentioned in the playbook as
become: yes

become_user : user2

I have copied the public key ~/.ssh/id_rsa.pub of user2 from server1  to ~/.ssh/authorized keys in all the other servers 

But its not working 

I am able to login with user1 and user2 from server1 to server2 to all the servers 

But when I am trying to execute the playbook it throws error 

I have tried to mention ansible_user= user1 in the inventory 

What shall I do ?

[Sakshi Jain]

also while executing the playbook from server1 , shall we execute as user1 or user2  ? 
and in inventory shall i mention as user1 or user2 
as in playbook, it needs the privileged permission from the sudo user