running systemctl via ssh without asking for password

Question

I want to run ssh without asking for password and invoke systemctl without password i tried doing the following:

ssh -t <user>@<host> "echo <password> | sudo -S systemctl status kubelet"

and:

sshpass -p '$<password>' ssh -t -o 'StrictHostKeyChecking=no' <user>@<host> 'sudo service kubelet restart

also:

 echo <password> | ssh -tt <user>@<host> "sudo service kubelet restart"

i added the user to the sudoers and i am able to run systemctl without password all the commands from above ask for a password except:

sshpass -p '$<password>' ssh -t -o 'StrictHostKeyChecking=no' <user>@<host> 'sudo service kubelet restart

which gives me no prompt and looks like it worked but did nothing.

Answer 1

sshpass only passes password for your ssh connection. But your "sudo service kubelet restart" - command itself asks for sudo password separately. Your systemctl status command does not need sudo privilege, that's why it goes through. Try it like this:

sshpass -p '$<password>' ssh -t -o 'StrictHostKeyChecking=no' <user>@<host> "echo <password> | sudo -S service kubelet restart"

Answer 2

I used python3 for this solution, and tho not elegant but it works(this is not the full script but only the relevant part).

initiate_restart = [
    "echo <password> | sudo -S systemctl restart kubelet",
    "echo <password> | sudo -S systemctl restart docker",
]
node = paramiko.SSHClient()
print(node)
node.set_missing_host_key_policy(paramiko.AutoAddPolicy())
try:
    node.connect(hostname=get_ip, username=user_name, password=node_pass)
    with open("/tmp/reset_log.log", "a") as f:
        f.write(date + ' Restarting ' + 'Node-' + get_ip + "\n")
except:
    print("[!] Cannot connect to the SSH Server")
    with open("/tmp/reset_log.log", "a") as f:
        f.write(date + ' Could not connect to' + ' Node-' + get_ip + "\n")
    exit()
for command in initiate_restart:
    print("="*50, command, "="*50)
    stdin, stdout, stderr = node.exec_command(command)
    print(stdout.read().decode())
    err = stderr.read().decode()
    if err:
        print(err)