salt,tests: Allow forcing the creation of an LV

In case a formatted LV was removed without wiping its FS signature,
creation from storage-operator will fail. We add support for an
annotation (metalk8s.scality.com/force-lvcreate) to force the creation
of the LV, at the risk of also wiping the previous FS contents.

CHANGELOG.md

@@ -6,6 +6,10 @@
 - Add `metalk8s-operator` to manage Workload Plane Ingress virtual IPs
   (PR[#3864](https://github.com/scality/metalk8s/pull/3864))
 
+- Add support for a `metalk8s.scality.com/force-lvcreate` annotation on `Volume`
+  objects of type `LVMLogicalVolume` to force the creation of their LV (use with
+  caution) (PR[#3877](https://github.com/scality/metalk8s/pull/3877))
+
 ### Removals
 
 - The deprecated long name `--archive` for the "add" option to the `iso-manager.sh`

docs/_infos/volumes.yaml

@@ -55,3 +55,11 @@ volume_types:
         lvmLogicalVolume:
           vgName: <vg_name>
           size: 10Gi
+    notes: |
+      .. tip::
+
+         You can add the ``metalk8s.scality.com/force-lvcreate`` annotation
+         (value does not matter) to LVMLogicalVolume objects to force the LV
+         creation. This will wipe any existing FS signature on the created LV,
+         so use with caution.
+         If the LV already exists however, it will just attempt to use it as is.

docs/operation/volume_management/volume_creation_deletion_cli.rst

@@ -38,6 +38,8 @@ Creating a Volume
        {% for key, info in volume_info["fields"].items() %}
        - **{{ key }}**: {{ info }}.
        {% endfor %}
+
+       {{ volume_info.get("notes", "") }}
        {% endfor %}
 
 #. Create the Volume.

salt/_modules/metalk8s_volumes.py

@@ -484,9 +484,17 @@ def exists(self):
         return bool(lv_info and lv_info.get(self.path))
 
     def create(self):
+        force_annotation = (
+            self.get("metadata")
+            .get("annotations", {})
+            .get("metalk8s.scality.com/force-lvcreate")
+        )
         try:
             ret = __salt__["lvm.lvcreate"](
-                lvname=self.lv_name, vgname=self.vg_name, size="{}b".format(self.size)
+                lvname=self.lv_name,
+                vgname=self.vg_name,
+                size="{}b".format(self.size),
+                force=force_annotation is not None,
             )
         except Exception as exc:
             raise CommandExecutionError(

salt/tests/unit/modules/files/test_metalk8s_volumes.yaml

@@ -137,7 +137,7 @@ _volumes_details: &volumes_details
         lastUpdateTime: '2020-07-11T13:55:26Z'
         status: 'True'
         type: Ready
-  my-lvm-lv-volume:
+  my-lvm-lv-volume: &_lv_volume
     apiVersion: storage.metalk8s.scality.com/v1alpha1
     kind: Volume
     metadata:
@@ -542,18 +542,37 @@ create:
         of: informations
       "Output from lvcreate": All good
     pillar_volumes: *volumes_details
+    lvcreate_forced: false
 
   # unable to create the LVM LV (raise when calling `lvcreate`)
   - name: my-lvm-lv-volume
     pillar_volumes: *volumes_details
     lvcreate: null
     raise_msg: "cannot create LVM LogicalVolume my-lvm-lv-volume in VG my_vg"
+    lvcreate_forced: false
 
   # unable to create the LVM LV (usual "vg does not exist")
   - name: my-lvm-lv-volume
     pillar_volumes: *volumes_details
     lvcreate: 'Volume group "my_vg" not found Penguin'
     raise_msg: 'cannot create LVM LogicalVolume my-lvm-lv-volume in VG my_vg: Volume group "my_vg" not found Penguin'
+    lvcreate_forced: false
+
+  # annotation to force the call to lvcreate
+  - name: example
+    pillar_volumes:
+      example:
+        <<: *_lv_volume
+        metadata:
+          name: example
+          uid: 6474cda7-0dbe-40fc-9842-3cb0404a725a
+          annotations:
+            metalk8s.scality.com/force-lvcreate: ""
+    lvcreate:
+      /dev/my_vg/example:
+        all: good
+      Output from lvcreate: All good
+    lvcreate_forced: true
 
   ## LVM LogicalVolume block volume
   # create a simple LVM LV volume
@@ -564,18 +583,21 @@ create:
         of: informations
       "Output from lvcreate": All good
     pillar_volumes: *volumes_details
+    lvcreate_forced: false
 
   # unable to create the LVM LV (raise when calling `lvcreate`)
   - name: my-lvm-lv-block-volume
     pillar_volumes: *volumes_details
     lvcreate: null
     raise_msg: "cannot create LVM LogicalVolume my-lvm-lv-block-volume in VG my_vg"
+    lvcreate_forced: false
 
   # unable to create the LVM LV (usual "vg does not exist")
   - name: my-lvm-lv-block-volume
     pillar_volumes: *volumes_details
     lvcreate: 'Volume group "my_vg" not found Penguin'
     raise_msg: 'cannot create LVM LogicalVolume my-lvm-lv-block-volume in VG my_vg: Volume group "my_vg" not found Penguin'
+    lvcreate_forced: false
 
   ## Invalid volumes
   # specified volume is not in the pillar

salt/tests/unit/modules/test_metalk8s_volumes.py

@@ -84,7 +84,13 @@ def test_exists(
 
     @utils.parameterized_from_cases(YAML_TESTS_CASES["create"])
     def test_create(
-        self, name, raise_msg=None, pillar_volumes=None, ftruncate=True, lvcreate=None
+        self,
+        name,
+        raise_msg=None,
+        pillar_volumes=None,
+        ftruncate=True,
+        lvcreate=None,
+        lvcreate_forced=None,
     ):
         """
         Tests the return of `create` function
@@ -123,6 +129,12 @@ def test_create(
                 # This function does not return anything
                 metalk8s_volumes.create(name)
 
+        if lvcreate_forced is not None:
+            lvcreate_mock.assert_called_once()
+            call_kwargs = lvcreate_mock.call_args[1]
+            self.assertIn("force", call_kwargs)
+            self.assertEqual(call_kwargs["force"], lvcreate_forced)
+
     @utils.parameterized_from_cases(YAML_TESTS_CASES["is_prepared"])
     def test_is_prepared(
         self,

tests/post/features/volume.feature

@@ -269,3 +269,36 @@ Feature: Volume management
         Then the Volume 'test-volume12-lvmlv' is 'Available'
         And the PersistentVolume 'test-volume12-lvmlv' has size '10Gi'
         And the device '/dev/test-vg-12/test-volume12-lvmlv' exists
+
+    Scenario: Test volume re-creation (lvmLogicalVolume force-lvcreate)
+        Given the Kubernetes API is available
+        And a LVM VG 'test-vg-13' exists
+        And a LVM LV 'test-lv-13' in VG 'test-vg-13' was created, formatted, then removed
+        When I create the following Volume:
+            apiVersion: storage.metalk8s.scality.com/v1alpha1
+            kind: Volume
+            metadata:
+              name: test-lv-13
+            spec:
+              nodeName: bootstrap
+              storageClassName: metalk8s
+              lvmLogicalVolume:
+                vgName: test-vg-13
+                size: 1Gi
+        Then the Volume 'test-lv-13' is 'Failed' with code 'CreationError' and message matches 'signature detected on /dev/test-vg-13/test-lv-13'
+        When I delete the Volume 'test-lv-13'
+        Then the Volume 'test-lv-13' does not exist
+        When I create the following Volume:
+            apiVersion: storage.metalk8s.scality.com/v1alpha1
+            kind: Volume
+            metadata:
+              name: test-lv-13
+              annotations:
+                metalk8s.scality.com/force-lvcreate: ""
+            spec:
+              nodeName: bootstrap
+              storageClassName: metalk8s
+              lvmLogicalVolume:
+                vgName: test-vg-13
+                size: 1Gi
+        Then the Volume 'test-lv-13' is 'Available'

tests/post/steps/test_volume.py

@@ -125,6 +125,14 @@ def test_volume_creation_lvmlv_block(host, teardown):
     pass
 
 
+@scenario(
+    "../features/volume.feature",
+    "Test volume re-creation (lvmLogicalVolume force-lvcreate)",
+)
+def test_volume_recreation_lvm_force(host, teardown):
+    pass
+
+
 # }}}
 # Given {{{
 
@@ -206,6 +214,29 @@ def storage_class_exist(name, sc_client):
         sc_client.create_from_yaml(kube_utils.DEFAULT_SC.format(name=name))
 
 
+@given(
+    parsers.parse(
+        "a LVM LV '{name}' in VG '{vg_name}' was created, formatted, then removed"
+    )
+)
+def lvm_lv_was_used(host, name, vg_name):
+    with host.sudo():
+        host.run_test(f"vgdisplay {vg_name}")
+        host.run_test(f"lvcreate -L 1G -n {name} {vg_name}")
+        host.run_test(f"mkfs.ext4 /dev/{vg_name}/{name}")
+        host.run_test(f"lvremove -y /dev/{vg_name}/{name}")
+
+    yield
+
+    with host.sudo():
+        lv_exists = host.run(f"lvdisplay /dev/{vg_name}/{name}")
+        if lv_exists.rc != 0:
+            # LV does not exist, attempt to recreate for wiping the signature
+            host.run_test(f"lvcreate -L 1G -n {name} -y {vg_name}")
+        host.run_test(f"wipefs -a /dev/{vg_name}/{name}")
+        host.run_test(f"lvremove -y /dev/{vg_name}/{name}")
+
+
 # }}}
 # When {{{