chore: add typing to cloudinit.distros.parsers hostname and resolv_conf

cloudinit/distros/parsers/hostname.py

@@ -5,21 +5,24 @@
 # This file is part of cloud-init. See LICENSE file for license information.
 
 from io import StringIO
+from typing import List, Optional, Tuple
 
 from cloudinit.distros.parsers import chop_comment
 
 
 # Parser that knows how to work with /etc/hostname format
 class HostnameConf:
-    def __init__(self, text):
+    def __init__(self, text: str) -> None:
         self._text = text
-        self._contents = None
+        self._parsed: bool = False
+        self._contents: List[Tuple[str, List[str]]] = []
 
-    def parse(self):
-        if self._contents is None:
+    def parse(self) -> None:
+        if not self._parsed:
             self._contents = self._parse(self._text)
+            self._parsed = True
 
-    def __str__(self):
+    def __str__(self) -> str:
         self.parse()
         contents = StringIO()
         for line_type, components in self._contents:
@@ -31,20 +34,20 @@ def __str__(self):
                 (hostname, tail) = components
                 contents.write("%s%s\n" % (hostname, tail))
         # Ensure trailing newline
-        contents = contents.getvalue()
-        if not contents.endswith("\n"):
-            contents += "\n"
-        return contents
+        rendered = contents.getvalue()
+        if not rendered.endswith("\n"):
+            rendered += "\n"
+        return rendered
 
     @property
-    def hostname(self):
+    def hostname(self) -> Optional[str]:
         self.parse()
         for line_type, components in self._contents:
             if line_type == "hostname":
                 return components[0]
         return None
 
-    def set_hostname(self, your_hostname):
+    def set_hostname(self, your_hostname: str) -> None:
         your_hostname = your_hostname.strip()
         if not your_hostname:
             return
@@ -57,7 +60,7 @@ def set_hostname(self, your_hostname):
         if not replaced:
             self._contents.append(("hostname", [str(your_hostname), ""]))
 
-    def _parse(self, contents):
+    def _parse(self, contents: str) -> List[Tuple[str, List[str]]]:
         entries = []
         hostnames_found = set()
         for line in contents.splitlines():

cloudinit/distros/parsers/resolv_conf.py

@@ -6,6 +6,7 @@
 
 import logging
 from io import StringIO
+from typing import List, Optional, Tuple
 
 from cloudinit import util
 from cloudinit.distros.parsers import chop_comment
@@ -15,36 +16,37 @@
 
 # See: man resolv.conf
 class ResolvConf:
-    def __init__(self, text):
+    def __init__(self, text: str) -> None:
         self._text = text
-        self._contents = None
+        self._parsed: bool = False
+        self._contents: List[Tuple[str, List[str]]] = []
 
-    def parse(self):
-        if self._contents is None:
+    def parse(self) -> None:
+        if not self._parsed:
             self._contents = self._parse(self._text)
+            self._parsed = True
 
     @property
-    def nameservers(self):
+    def nameservers(self) -> List[str]:
         self.parse()
         return self._retr_option("nameserver")
 
     @property
-    def local_domain(self):
+    def local_domain(self) -> Optional[str]:
         self.parse()
         dm = self._retr_option("domain")
         if dm:
             return dm[0]
         return None
 
     @local_domain.setter
-    def local_domain(self, domain):
+    def local_domain(self, domain: str) -> None:
         self.parse()
         self._remove_option("domain")
         self._contents.append(("option", ["domain", str(domain), ""]))
-        return domain
 
     @property
-    def search_domains(self):
+    def search_domains(self) -> List[str]:
         self.parse()
         current_sds = self._retr_option("search")
         flat_sds = []
@@ -54,7 +56,7 @@ def search_domains(self):
                     flat_sds.append(sd)
         return flat_sds
 
-    def __str__(self):
+    def __str__(self) -> str:
         self.parse()
         contents = StringIO()
         for line_type, components in self._contents:
@@ -70,7 +72,7 @@ def __str__(self):
                 contents.write("%s\n" % (line))
         return contents.getvalue()
 
-    def _retr_option(self, opt_name):
+    def _retr_option(self, opt_name: str) -> List[str]:
         found = []
         for line_type, components in self._contents:
             if line_type == "option":
@@ -79,7 +81,7 @@ def _retr_option(self, opt_name):
                     found.append(cfg_value)
         return found
 
-    def add_nameserver(self, ns):
+    def add_nameserver(self, ns: str) -> List[str]:
         self.parse()
         current_ns = self._retr_option("nameserver")
         new_ns = list(current_ns)
@@ -92,7 +94,7 @@ def add_nameserver(self, ns):
             self._contents.append(("option", ["nameserver", n, ""]))
         return new_ns
 
-    def _remove_option(self, opt_name):
+    def _remove_option(self, opt_name: str) -> None:
         def remove_opt(item):
             line_type, components = item
             if line_type != "option":
@@ -108,7 +110,7 @@ def remove_opt(item):
                 new_contents.append(c)
         self._contents = new_contents
 
-    def add_search_domain(self, search_domain):
+    def add_search_domain(self, search_domain: str) -> List[str]:
         flat_sds = self.search_domains
         new_sds = list(flat_sds)
         new_sds.append(str(search_domain))
@@ -132,7 +134,7 @@ def add_search_domain(self, search_domain):
         self._contents.append(("option", ["search", s_list, ""]))
         return flat_sds
 
-    def _parse(self, contents):
+    def _parse(self, contents: str) -> List[Tuple[str, List[str]]]:
         entries = []
         for i, line in enumerate(contents.splitlines()):
             sline = line.strip()

pyproject.toml

@@ -51,9 +51,7 @@ module = [
     "cloudinit.distros.azurelinux",
     "cloudinit.distros.bsd",
     "cloudinit.distros.opensuse",
-    "cloudinit.distros.parsers.hostname",
     "cloudinit.distros.parsers.hosts",
-    "cloudinit.distros.parsers.resolv_conf",
     "cloudinit.distros.ug_util",
     "cloudinit.helpers",
     "cloudinit.net.cmdline",