Merge ~andreserl/maas:2.3_lp1758760 into maas:2.3

[Andres Rodriguez]

Backport e3e619165309a6f180a3366d8d8d4372521bb8bb from master

LP: #1758760 - Ensure there's no two consecutive occurrences of the same character

[Andres Rodriguez (andreserl)]

review: Approve

diff --git a/src/metadataserver/user_data/templates/snippets/maas_ipmi_autodetect.py b/src/metadataserver/user_data/templates/snippets/maas_ipmi_autodetect.py
index cd53215..49a9424 100644
--- a/src/metadataserver/user_data/templates/snippets/maas_ipmi_autodetect.py
+++ b/src/metadataserver/user_data/templates/snippets/maas_ipmi_autodetect.py
@@ -301,8 +301,12 @@ def generate_random_password(
         # Create the extra characters to fullfill max_length
         letters += ''.join([
             random.choice(string.ascii_letters) for _ in range(length - 7)])
-        # Randomly mix the password
-        return ''.join(random.sample(letters, len(letters)))
+        # LP: #1758760 - Randomly mix the password until we ensure there's
+        # not consecutive occurrences of the same character.
+        password = ''.join(random.sample(letters, len(letters)))
+        while (bool(re.search(r'(.)\1', password))):
+            password = ''.join(random.sample(letters, len(letters)))
+        return password
     else:
         letters = string.ascii_letters + string.digits
         return ''.join([random.choice(letters) for _ in range(length)])
diff --git a/src/metadataserver/user_data/templates/snippets/tests/test_maas_ipmi_autodetect.py b/src/metadataserver/user_data/templates/snippets/tests/test_maas_ipmi_autodetect.py
index 31ef8c3..e79740b 100644
--- a/src/metadataserver/user_data/templates/snippets/tests/test_maas_ipmi_autodetect.py
+++ b/src/metadataserver/user_data/templates/snippets/tests/test_maas_ipmi_autodetect.py
@@ -513,6 +513,10 @@ class TestGeneratesAcceptablePasswords(MAASTestCase):
                 required_character_sets += 1
             if required_character_sets < 2:
                 return False
+            # Test password doesn't have two or more occurrences of the
+            # the same consecutive character.
+            if bool(re.search(r'(.)\1', password)):
+                return False
             return True
         max_attempts = 100
         acceptable = 0