Avoid downloading growpart

github is not exactly reliable these days.
use sfdisk, which is also used by growpart internally

Signed-off-by: Gaëtan Lehmann <gaetan.lehmann@vates.tech>

Author: glehmann

lib/vm.py

@@ -510,13 +510,7 @@ def detect_package_manager(self) -> PackageManagerEnum:
 
     def grow_root_partition(self) -> int | None:
         if self.detect_package_manager() == PackageManagerEnum.APK:
-            # growpart is not available in alpine 3.12
-            # vm.ssh('apk add cloud-utils-growpart e2fsprogs-extra')
-            self.ssh('apk add gawk util-linux e2fsprogs-extra')
-            self.ssh(
-                'wget https://raw.githubusercontent.com/canonical/cloud-utils/main/bin/growpart -O /usr/bin/growpart'
-            )
-            self.ssh('chmod +x /usr/bin/growpart')
+            self.ssh('apk add util-linux e2fsprogs-extra')
         else:
             return None
         mount_output = self.ssh('mount').strip()
@@ -526,8 +520,8 @@ def grow_root_partition(self) -> int | None:
         if not typ.startswith('ext'):
             logging.debug(f"Unsupported filesystem: {typ}")
             return None
-        growpart_returncode = self.ssh_with_result(f'growpart /dev/{disk} {partition}').returncode
-        assert growpart_returncode in [0, 1] # growpart returns 1 if the size is already the expected one
+        self.ssh(f'echo ", +" | sfdisk --no-reread --force -N {partition} /dev/{disk}')
+        self.ssh(f'partx -u -n {partition}:{partition} /dev/{disk}')
         self.ssh(f'resize2fs /dev/{disk}{p}{partition}')
         df_output = self.ssh('df /')
         return int(df_output.splitlines()[-1].split()[3]) * KiB