Add configuration options for DISK_WAIT

https://review.openstack.org/#/c/320295/ introduced two internal
variables: _DISK_WAIT_ATTEMPTS and _DISK_WAIT_DELAY. These values are
hardcoded. This patch adds configuration options for these so
that an operator can change them based on their own needs/fleet of
hardware.

Change-Id: I2ba97669ec710fb4a435307466cd8add9c2293ba
Closes-Bug: #1585663

ironic_python_agent/config.py

@@ -128,6 +128,18 @@ cli_opts = [
                default=APARAMS.get('ipa-hardware-initialization-delay', 0),
                help='How much time (in seconds) to wait for hardware to '
                     'initialize before proceeding with any actions.'),
+
+    cfg.IntOpt('disk_wait_attempts',
+               default=APARAMS.get('ipa-disk-wait-attempts', 10),
+               help='The number of times to try and check to see if '
+                    'at least one suitable disk has appeared in inventory '
+                    'before proceeding with any actions.'),
+
+    cfg.IntOpt('disk_wait_delay',
+               default=APARAMS.get('ipa-disk-wait-delay', 3),
+               help='How much time (in seconds) to wait between attempts '
+                    'to check if at least one suitable disk has appeared '
+                    'in inventory.'),
 ]
 
 CONF.register_cli_opts(cli_opts)