diff --git a/tests/unit/cli/test_create_docker_role.py b/tests/unit/cli/test_create_docker_role.py
new file mode 100644
index 00000000..b6f68acc
--- /dev/null
+++ b/tests/unit/cli/test_create_docker_role.py
@@ -0,0 +1,137 @@
+import unittest
+import ipaddress
+import os
+import shutil
+import tempfile
+from ruamel.yaml import YAML
+
+# Import functions to test; adjust path as needed
+from cli.create_docker_role import (
+    get_next_network,
+    get_next_port,
+    load_yaml_with_comments,
+    dump_yaml_with_comments,
+    render_templates
+)
+
+class TestCreateDockerRoleCLI(unittest.TestCase):
+    def setUp(self):
+        # Temporary directory for YAML files and templates
+        self.tmpdir = tempfile.mkdtemp()
+        self.ports_file = os.path.join(self.tmpdir, '09_ports.yml')
+        self.networks_file = os.path.join(self.tmpdir, '10_networks.yml')
+
+    def tearDown(self):
+        shutil.rmtree(self.tmpdir)
+
+    def test_get_next_network_multiple(self):
+        networks = {
+            'defaults_networks': {
+                'local': {
+                    'app1': {'subnet': '192.168.0.0/28'},
+                    'app2': {'subnet': '192.168.0.16/28'},
+                }
+            }
+        }
+        next_net = get_next_network(networks, 28)
+        self.assertEqual(next_net, ipaddress.ip_network('192.168.0.32/28'))
+
+    def test_get_next_network_single(self):
+        networks = {
+            'defaults_networks': {
+                'local': {
+                    'only': {'subnet': '10.0.0.0/24'},
+                }
+            }
+        }
+        next_net = get_next_network(networks, 24)
+        self.assertEqual(next_net, ipaddress.ip_network('10.0.1.0/24'))
+
+    def test_get_next_port_existing(self):
+        ports = {
+            'ports': {
+                'localhost': {
+                    'http': {'app1': '8000', 'app2': '8001'}
+                }
+            }
+        }
+        next_port = get_next_port(ports, 'http')
+        self.assertEqual(next_port, 8002)
+
+    def test_get_next_port_empty(self):
+        ports = {
+            'ports': {
+                'localhost': {
+                    'ldap': {}
+                }
+            }
+        }
+        next_port = get_next_port(ports, 'ldap')
+        self.assertEqual(next_port, 1)
+
+    def test_yaml_load_dump_preserves_comments(self):
+        # Initialize ruamel.yaml
+        yaml = YAML()
+        yaml.preserve_quotes = True
+        # Create sample file with comment
+        content = (
+            '# Ports file\n'
+            'ports:\n'
+            '  localhost:\n'
+            '    http:\n'
+            '      app1: 8000  # existing port\n'
+        )
+        with open(self.ports_file, 'w') as f:
+            f.write(content)
+        # Load and modify
+        data = load_yaml_with_comments(self.ports_file)
+        data['ports']['localhost']['http']['app2'] = 8001
+        dump_yaml_with_comments(data, self.ports_file)
+        # Check comment and new entry
+        text = open(self.ports_file).read()
+        self.assertIn('# existing port', text)
+        self.assertIn('app2: 8001', text)
+
+    def test_render_creates_and_overwrites_skips_merges(self):
+        # Prepare source and dest directories
+        src = os.path.join(self.tmpdir, 'src')
+        dst = os.path.join(self.tmpdir, 'dst')
+        os.makedirs(src)
+        os.makedirs(dst)
+        # Template file
+        tpl = os.path.join(src, 'file.txt.j2')
+        with open(tpl, 'w') as f:
+            f.write('Line1\nLine2')
+        out_file = os.path.join(dst, 'file.txt')
+        # Test create
+        render_templates(src, dst, {})
+        with open(out_file) as f:
+            self.assertEqual(f.read(), 'Line1\nLine2')
+        # Test overwrite
+        with open(out_file, 'w') as f:
+            f.write('Old')
+        import builtins
+        original_input = builtins.input
+        builtins.input = lambda _: '1'
+        render_templates(src, dst, {})
+        with open(out_file) as f:
+            self.assertEqual(f.read(), 'Line1\nLine2')
+        # Test skip
+        with open(out_file, 'w') as f:
+            f.write('Old')
+        builtins.input = lambda _: '2'
+        render_templates(src, dst, {})
+        with open(out_file) as f:
+            self.assertEqual(f.read(), 'Old')
+        # Test merge
+        with open(out_file, 'w') as f:
+            f.write('Line1\n')
+        builtins.input = lambda _: '3'
+        render_templates(src, dst, {})
+        content = open(out_file).read().splitlines()
+        self.assertIn('Line1', content)
+        self.assertIn('Line2', content)
+        builtins.input = original_input
+
+if __name__ == '__main__':
+    unittest.main()