Handle the entries clean up properly

Add test to capture user interfering with /etc/hosts
and to guarantee the /etc/hosts cleanup works as expected

lib/cloudregister/registerutils.py

@@ -107,19 +107,12 @@ def clean_hosts_file(domain_name):
         content = hosts_file.readlines()
 
     smt_announce_found = None
-    smt_domain_found = None
     for entry in content:
         if b'# Added by SMT' in entry:
             smt_announce_found = True
             continue
-        if smt_announce_found and domain_name in entry:
-            smt_announce_found = False
-            smt_domain_found = True
-            continue
-        if smt_domain_found:
-            smt_domain_found = False
-            if b'registry' in entry and domain_name in entry:
-                # registry entry is optional
+        if smt_announce_found:
+            if domain_name in entry:
                 continue
 
         new_hosts_content.append(entry)

tests/test_registerutils.py

@@ -335,6 +335,42 @@ def test_clean_host_file_no_empty_bottom_lines():
 1.2.3.4   smt-foo.susecloud.net  smt-foo
 
 
+4.3.2.1   another_entry.whatever.com another_entry"""
+    with mock.patch('builtins.open', mock.mock_open(read_data=hosts_content.encode())) as m:  # noqa: E501
+        utils.clean_hosts_file('susecloud.net')
+
+    expected_write_calls = []
+    expected_lines = expected_cleaned_hosts.split('\n')
+    for line in expected_lines[:-1]:
+        line = line + '\n'
+        expected_write_calls.append(call(line.encode()))
+    if expected_lines[-1] != '':
+        expected_write_calls.append(call(expected_lines[-1].encode()))
+
+    expected_write_calls.append(call(b'\n'))
+
+    assert m().write.mock_calls == expected_write_calls
+
+
+def test_clean_host_file_no_empty_bottom_lines_user_interfered():
+    hosts_content = """
+# simulates hosts file containing the ipv6 we are looking for in the test
+
+1.2.3.4   smt-foo.susecloud.net  smt-foo
+
+# Added by SMT, please, do NOT remove this line
+2.3.4.5   smt-entry.susecloud.net smt-entry
+1.1.1.1   my.specialhost.us
+2.3.4.5   registry-entry.susecloud.net
+
+4.3.2.1   another_entry.whatever.com another_entry"""
+    expected_cleaned_hosts = """
+# simulates hosts file containing the ipv6 we are looking for in the test
+
+1.2.3.4   smt-foo.susecloud.net  smt-foo
+
+1.1.1.1   my.specialhost.us
+
 4.3.2.1   another_entry.whatever.com another_entry"""
     with mock.patch('builtins.open', mock.mock_open(read_data=hosts_content.encode())) as m:  # noqa: E501
         utils.clean_hosts_file('susecloud.net')