fix(apt): Allow opt-in for calling apt update multiple times

This is required to configure apt when dependency is not installed.

Fixes canonicalGH-5223

cloudinit/config/cc_apt_configure.py

@@ -747,7 +747,9 @@ def _ensure_dependencies(cfg, aa_repo_match, cloud):
         if not shutil.which(command):
             missing_packages.append(PACKAGE_DEPENDENCY_BY_COMMAND[command])
     if missing_packages:
-        cloud.distro.install_packages(sorted(missing_packages))
+        cloud.distro.install_packages(
+            sorted(missing_packages), allow_subsequent_updates=True
+        )
 
 
 def add_apt_key(ent, cloud, gpg, hardened=False, file_name=None):

cloudinit/distros/package_management/apt.py

@@ -108,13 +108,16 @@ def from_config(cls, runner: helpers.Runners, cfg: Mapping) -> "Apt":
     def available(self) -> bool:
         return bool(subp.which(self.apt_get_command[0]))
 
-    def update_package_sources(self):
-        self.runner.run(
-            "update-sources",
-            self.run_package_command,
-            ["update"],
-            freq=PER_INSTANCE,
-        )
+    def update_package_sources(self, allow_subsequent_updates: bool = False):
+        if allow_subsequent_updates:
+            self.run_package_command(["update"])
+        else:
+            self.runner.run(
+                "update-sources",
+                self.run_package_command,
+                ["update"],
+                freq=PER_INSTANCE,
+            )
 
     @functools.lru_cache(maxsize=1)
     def get_all_packages(self):
@@ -140,8 +143,11 @@ def get_unavailable_packages(self, pkglist: Iterable[str]):
             not in self.get_all_packages()
         ]
 
-    def install_packages(self, pkglist: Iterable) -> UninstalledPackages:
-        self.update_package_sources()
+    def install_packages(
+        self, pkglist: Iterable, allow_subsequent_updates: bool = False
+    ) -> UninstalledPackages:
+        if not allow_subsequent_updates:
+            self.update_package_sources()
         pkglist = util.expand_package_list("%s=%s", list(pkglist))
         unavailable = self.get_unavailable_packages(
             [x.split("=")[0] for x in pkglist]

cloudinit/distros/package_management/package_manager.py

@@ -26,7 +26,9 @@ def update_package_sources(self):
         ...
 
     @abstractmethod
-    def install_packages(self, pkglist: Iterable) -> UninstalledPackages:
+    def install_packages(
+        self, pkglist: Iterable, allow_subsequent_updates: bool = False
+    ) -> UninstalledPackages:
         """Install the given packages.
 
         Return a list of packages that failed to install.

cloudinit/distros/package_management/snap.py

@@ -20,7 +20,9 @@ def available(self) -> bool:
     def update_package_sources(self):
         pass
 
-    def install_packages(self, pkglist: Iterable) -> UninstalledPackages:
+    def install_packages(
+        self, pkglist: Iterable, allow_subsequent_updates: bool = False
+    ) -> UninstalledPackages:
         # Snap doesn't provide us with a mechanism to know which packages
         # are available or have failed, so install one at a time
         pkglist = util.expand_package_list("%s=%s", list(pkglist))

tests/unittests/config/test_cc_apt_configure.py

@@ -268,7 +268,9 @@ def fake_which(cmd):
         which.side_effect = fake_which
         cc_apt._ensure_dependencies(cfg, matcher, mycloud)
         if expected_install:
-            install_packages.assert_called_once_with(expected_install)
+            install_packages.assert_called_once_with(
+                expected_install, allow_subsequent_updates=True
+            )
         else:
             install_packages.assert_not_called()