Add collective show

Provide a harmless way to look at collective state

confluent_server/bin/collective

@@ -1,6 +1,7 @@
 #!/usr/bin/env python
 
 import argparse
+import errno
 import os
 import socket
 import subprocess
@@ -22,6 +23,13 @@ except NameError:
 
 def make_certificate():
     umask = os.umask(0077)
+    try:
+        os.makedirs('/etc/confluent/cfg')
+    except OSError as e:
+        if e.errno == errno.EEXIST and os.path.isdir('/etc/confluent/cfg'):
+            pass
+        else:
+            raise
     if subprocess.check_call(
             'openssl ecparam -name secp384r1 -genkey -out '
             '/etc/confluent/privkey.pem'.split(' ')):
@@ -62,11 +70,18 @@ def join_collective(server, invitation):
                   {'status': 'Unknown response: ' + repr(res)})['status'])
 
 
+def show_collective():
+    s = client.Command().connection
+    tlvdata.send(s, {'collective': {'operation': 'show'}})
+    res = tlvdata.recv(s)
+    print(repr(res))
+
 def main():
     a = argparse.ArgumentParser(description='Confluent server utility')
     sp = a.add_subparsers(dest='command')
     gc = sp.add_parser('gencert', help='Generate Confluent Certificates for '
                                 'collective mode and remote CLI access')
+    sl = sp.add_parser('show', help='Show information about the collective')
     ic = sp.add_parser('invite', help='Generate a invitation to allow a new '
                                     'confluent instance to join as a '
                                     'collective member')
@@ -83,6 +98,8 @@ def main():
         show_invitation(cmdset.name)
     elif cmdset.command == 'join':
         join_collective(cmdset.server, cmdset.i)
+    elif cmdset.command == 'show':
+        show_collective()
 
 if __name__ == '__main__':
     main()

confluent_server/confluent/collective/manager.py

@@ -160,6 +160,21 @@ def handle_connection(connection, cert, request, local=False):
     else:
         if not local:
             return
+
+        if 'show' == operation:
+            try:
+                cfm.check_quorum()
+            except exc.DegradedCollective:
+                tlvdata.send(connection,
+                    {'collective':
+                         {'error': 'Collective does not have quorum'}})
+            if follower:
+                myleader = cfm.get_collective_member_by_address(
+                    currentleader)['name']
+            else:
+                myleader = get_myname()
+            tlvdata.send(connection, {'collective':  {'leader': myleader}})
+            return
         if 'invite' == operation:
             if follower:
                 tlvdata.send(connection,