launch: remove local mode for sshfp records

The "non-local" mode was added to this for the old Bionic based bridge
node, whose version of ssh-keyscan didn't have "-D", so we had to
actually log into the remote host to query its keys.

Now this runs on a Jammy node, we can remove this and just use the
remote probe.  We don't have to worry about comaptability of this
tool, so I've just removed these bits.

Change-Id: Ie8254a965597db5695ff1613fc4ebf8cc26f3a25

launch/src/opendev_launch/sshfp.py

@@ -3,19 +3,11 @@
 import argparse
 import subprocess
 
-def generate_sshfp_records(hostname, ip, local):
+def generate_sshfp_records(hostname, ip):
     '''Given a hostname and and IP address, scan the IP address (hostname
     not in dns yet) and return a bind string with sshfp records'''
 
-    if local:
+    p = ['ssh-keyscan', '-D', ip]
-        p = ['ssh-keyscan', '-D', ip]
-    else:
-        # Handle being run via sudo which is the usual way
-        # this is run.
-        p = ['ssh', '-o', 'StrictHostKeyChecking=no',
-             '-i', '/root/.ssh/id_rsa',
-             'root@%s' % ip, 'ssh-keygen', '-r', ip]
-
     s = subprocess.run(p,
                        stdout=subprocess.PIPE,
                        stderr=subprocess.PIPE).stdout.decode('utf-8')
@@ -46,19 +38,17 @@ def generate_sshfp_records(hostname, ip, local):
     return ret
 
 
-def sshfp_print_records(hostname, ip, local=False):
+def sshfp_print_records(hostname, ip):
-    print(generate_sshfp_records(hostname, ip, local))
+    print(generate_sshfp_records(hostname, ip))
 
 
 def main():
     parser = argparse.ArgumentParser()
     parser.add_argument("hostname", help="hostname")
     parser.add_argument("ip", help="address to scan")
-    parser.add_argument("--local", action='store_true',
-                        help="Run keyscan locally, rather than via ssh")
     args = parser.parse_args()
 
-    sshfp_print_records(args.hostname, args.ip, args.local)
+    sshfp_print_records(args.hostname, args.ip)
 
 if __name__ == '__main__':
     main()