Generate stack name as a valid hostname

Truncate cluster name to 30 characters, map ('_', '.') to '-' and remove non
alpha-numeric characters.

Change-Id: Ibb2bddc5b602a34d0e2bebd1f6bb197669bf21ec
Close-Bug: #1718947

magnum/drivers/heat/driver.py

@@ -14,6 +14,9 @@ import abc
 import os
 import six
 
+from string import ascii_letters
+from string import digits
+
 from oslo_config import cfg
 from oslo_log import log as logging
 from oslo_utils import importutils
@@ -109,8 +112,18 @@ class HeatDriver(driver.Driver):
                                                          env_files)
         tpl_files.update(env_map)
 
+        # Make sure we end up with a valid hostname
+        valid_chars = set(ascii_letters + digits + '-')
+
+        # valid hostnames are 63 chars long, leaving enough room
+        # to add the random id (for uniqueness)
+        stack_name = cluster.name[:30]
+        stack_name = stack_name.replace('_', '-')
+        stack_name = stack_name.replace('.', '-')
+        stack_name = ''.join(filter(valid_chars.__contains__, stack_name))
+
         # Make sure no duplicate stack name
-        stack_name = '%s-%s' % (cluster.name, short_id.generate_id())
+        stack_name = '%s-%s' % (stack_name, short_id.generate_id())
         if cluster_create_timeout:
             heat_timeout = cluster_create_timeout
         else:

magnum/tests/unit/conductor/handlers/test_k8s_cluster_conductor.py

@@ -755,7 +755,7 @@ class TestClusterConductorWithK8s(base.TestCase):
                           mock_generate_id):
 
         mock_generate_id.return_value = 'xx-xx-xx-xx'
-        expected_stack_name = 'expected_stack_name-xx-xx-xx-xx'
+        expected_stack_name = 'expected-stack-name-xx-xx-xx-xx'
         expected_template_contents = 'template_contents'
         dummy_cluster_name = 'expected_stack_name'
         expected_timeout = 15
@@ -796,7 +796,7 @@ class TestClusterConductorWithK8s(base.TestCase):
             mock_generate_id):
 
         mock_generate_id.return_value = 'xx-xx-xx-xx'
-        expected_stack_name = 'expected_stack_name-xx-xx-xx-xx'
+        expected_stack_name = 'expected-stack-name-xx-xx-xx-xx'
         expected_template_contents = 'template_contents'
         dummy_cluster_name = 'expected_stack_name'
         expected_timeout = CONF.cluster_heat.create_timeout
@@ -836,7 +836,7 @@ class TestClusterConductorWithK8s(base.TestCase):
             mock_generate_id):
 
         mock_generate_id.return_value = 'xx-xx-xx-xx'
-        expected_stack_name = 'expected_stack_name-xx-xx-xx-xx'
+        expected_stack_name = 'expected-stack-name-xx-xx-xx-xx'
         expected_template_contents = 'template_contents'
         dummy_cluster_name = 'expected_stack_name'
         cluster_timeout = 0

releasenotes/notes/bug-1718947-0d4e67529e2817d7.yaml

@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    From now on, server names are prefixed with the cluster name.
+    The cluster name is truncated to 30 characters, ('_', '.') are mapped to '-'
+    and non alpha-numeric characters are removed to ensure FQDN compatibility.