Move root partition resizing logic to VM.grow_root_partition()

And make it a bit more robust, by:
- fetching the actual partition mounted on /
- checking if the filesystem is ext*

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

Author: glehmann

lib/vm.py

@@ -4,6 +4,7 @@
 
 import logging
 import os
+import re
 import subprocess
 import tempfile
 import uuid
@@ -12,6 +13,7 @@
 import lib.efi as efi
 from lib.basevm import BaseVM
 from lib.common import (
+    KiB,
     PackageManagerEnum,
     expand_scope_relative_nodeid,
     parse_xe_dict,
@@ -506,6 +508,30 @@ def detect_package_manager(self) -> PackageManagerEnum:
             return PackageManagerEnum.APK
         return PackageManagerEnum.UNKNOWN
 
+    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')
+        else:
+            return None
+        mount_output = self.ssh('mount').strip()
+        root_match = re.search(r'/dev/(\w+?)(p?)(\d+) on / type (\w+)', mount_output)
+        assert root_match is not None
+        disk, p, partition, typ = root_match.groups()
+        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'resize2fs /dev/{disk}{p}{partition}')
+        df_output = self.ssh('df /')
+        return int(df_output.splitlines()[-1].split()[3]) * KiB
+
     def insert_cd(self, vdi_name: str) -> None:
         logging.info("Insert CD %r in VM %s", vdi_name, self.uuid)
         self.host.xe('vm-cd-insert', {'uuid': self.uuid, 'cd-name': vdi_name})

tests/storage/storage.py

@@ -241,17 +241,9 @@ def xva_export_import(source_vm: VM, compression: XVACompression, temp_large_dir
     vm.wait_for_vm_running_and_ssh_up()
     install_randstream(vm)
 
-    if vm.detect_package_manager() == PackageManagerEnum.APK:
-        # growpart is not available in alpine 3.12
-        # vm.ssh('apk add cloud-utils-growpart e2fsprogs-extra')
-        vm.ssh('apk add gawk util-linux e2fsprogs-extra')
-        vm.ssh('wget https://raw.githubusercontent.com/canonical/cloud-utils/main/bin/growpart -O /usr/bin/growpart')
-        vm.ssh('chmod +x /usr/bin/growpart')
-        # TODO: maybe use `findmnt -no SOURCE /` from util-linux to get the blockdevice mounted on /
-        growpart_returncode = vm.ssh_with_result('growpart /dev/xvda 3').returncode
-        assert growpart_returncode in [0, 1] # growpart returns 1 if the size is already the expected one
-        vm.ssh('resize2fs /dev/xvda3')
-        stream_size = min(volume_size // 2, config.write_volume_cap)
+    root_partition_size = vm.grow_root_partition()
+    if root_partition_size is not None:
+        stream_size = min(root_partition_size // 2, config.write_volume_cap)
     else:
         stream_size = 500 * MiB