Implement VM rollback

Closes #184

api-daemon/pvcapid/flaskapi.py

@@ -3202,6 +3202,54 @@ class API_VM_Snapshot(Resource):
 api.add_resource(API_VM_Snapshot, "/vm/<vm>/snapshot")
 
 
+# /vm/<vm>/snapshot/rollback
+class API_VM_Snapshot_Rollback(Resource):
+    @RequestParser(
+        [
+            {
+                "name": "snapshot_name",
+                "required": True,
+                "helptext": "A snapshot name must be specified",
+            },
+        ]
+    )
+    @Authenticator
+    def post(self, vm, reqargs):
+        """
+        Roll back to a snapshot of a VM's disks and configuration
+        ---
+        tags:
+          - vm
+        parameters:
+          - in: query
+            name: snapshot_name
+            type: string
+            required: true
+            description: The name of the snapshot to roll back to
+        responses:
+          200:
+            description: OK
+            schema:
+              type: object
+              id: Message
+          400:
+            description: Execution error
+            schema:
+              type: object
+              id: Message
+          404:
+            description: Not found
+            schema:
+              type: object
+              id: Message
+        """
+        snapshot_name = reqargs.get("snapshot_name", None)
+        return api_helper.rollback_vm_snapshot(vm, snapshot_name)
+
+
+api.add_resource(API_VM_Snapshot_Rollback, "/vm/<vm>/snapshot/rollback")
+
+
 ##########################################################
 # Client API - Network
 ##########################################################

api-daemon/pvcapid/helper.py

@@ -813,6 +813,30 @@ def remove_vm_snapshot(
     return output, retcode
 
 
+@ZKConnection(config)
+def rollback_vm_snapshot(
+    zkhandler,
+    domain,
+    snapshot_name,
+):
+    """
+    Roll back to a snapshot of a VM.
+    """
+    retflag, retdata = pvc_vm.rollback_vm_snapshot(
+        zkhandler,
+        domain,
+        snapshot_name,
+    )
+
+    if retflag:
+        retcode = 200
+    else:
+        retcode = 400
+
+    output = {"message": retdata.replace('"', "'")}
+    return output, retcode
+
+
 @ZKConnection(config)
 def vm_attach_device(zkhandler, vm, device_spec_xml):
     """

client-cli/pvc/cli/cli.py

@@ -1787,7 +1787,7 @@ def cli_vm_snapshot():
 @connection_req
 @click.argument("domain")
 @click.argument("snapshot_name", required=False, default=None)
-def cli_vm_snapshot_remove(domain, snapshot_name):
+def cli_vm_snapshot_create(domain, snapshot_name):
     """
     Create a snapshot of the disks and XML configuration of virtual machine DOMAIN, with the
     optional name SNAPSHOT_NAME. DOMAIN may be a UUID or name.
@@ -1819,7 +1819,7 @@ def cli_vm_snapshot_remove(domain, snapshot_name):
 @connection_req
 @click.argument("domain")
 @click.argument("snapshot_name")
-def cli_vm_snapshot_create(domain, snapshot_name):
+def cli_vm_snapshot_remove(domain, snapshot_name):
     """
     Remove the snapshot SNAPSHOT_NAME of the disks and XML configuration of virtual machine DOMAIN,
     DOMAIN may be a UUID or name.
@@ -1838,6 +1838,37 @@ def cli_vm_snapshot_create(domain, snapshot_name):
     finish(retcode, retmsg)
 
 
+###############################################################################
+# > pvc vm snapshot rollback
+###############################################################################
+@click.command(
+    name="rollback", short_help="Roll back to a snapshot of a virtual machine."
+)
+@connection_req
+@click.argument("domain")
+@click.argument("snapshot_name")
+@confirm_opt(
+    "Roll back to snapshot {snapshot_name} of {domain} and lose all data and changes since this snapshot"
+)
+def cli_vm_snapshot_rollback(domain, snapshot_name):
+    """
+    Roll back to the snapshot SNAPSHOT_NAME of the disks and XML configuration of virtual machine DOMAIN,
+    DOMAIN may be a UUID or name.
+    """
+
+    echo(
+        CLI_CONFIG,
+        f"Rolling back to snapshot '{snapshot_name}' of VM '{domain}'... ",
+        newline=False,
+    )
+    retcode, retmsg = pvc.lib.vm.vm_rollback_snapshot(CLI_CONFIG, domain, snapshot_name)
+    if retcode:
+        echo(CLI_CONFIG, "done.")
+    else:
+        echo(CLI_CONFIG, "failed.")
+    finish(retcode, retmsg)
+
+
 ###############################################################################
 # > pvc vm backup
 ###############################################################################
@@ -6377,6 +6408,7 @@ cli_vm.add_command(cli_vm_unmigrate)
 cli_vm.add_command(cli_vm_flush_locks)
 cli_vm_snapshot.add_command(cli_vm_snapshot_create)
 cli_vm_snapshot.add_command(cli_vm_snapshot_remove)
+cli_vm_snapshot.add_command(cli_vm_snapshot_rollback)
 cli_vm.add_command(cli_vm_snapshot)
 cli_vm_backup.add_command(cli_vm_backup_create)
 cli_vm_backup.add_command(cli_vm_backup_restore)

client-cli/pvc/lib/vm.py

@@ -538,6 +538,25 @@ def vm_remove_snapshot(config, vm, snapshot_name):
         return True, response.json().get("message", "")
 
 
+def vm_rollback_snapshot(config, vm, snapshot_name):
+    """
+    Roll back to a snapshot of a VM's disks and configuration
+
+    API endpoint: POST /vm/{vm}/snapshot/rollback
+    API arguments: snapshot_name=snapshot_name
+    API schema: {"message":"{data}"}
+    """
+    params = {"snapshot_name": snapshot_name}
+    response = call_api(
+        config, "post", "/vm/{vm}/snapshot/rollback".format(vm=vm), params=params
+    )
+
+    if response.status_code != 200:
+        return False, response.json().get("message", "")
+    else:
+        return True, response.json().get("message", "")
+
+
 def vm_vcpus_set(config, vm, vcpus, topology, restart):
     """
     Set the vCPU count of the VM with topology

daemon-common/vm.py

@@ -1396,7 +1396,67 @@ def remove_vm_snapshot(zkhandler, domain, snapshot_name):
 
 
 def rollback_vm_snapshot(zkhandler, domain, snapshot_name):
-    pass
+    # Validate that VM exists in cluster
+    dom_uuid = getDomainUUID(zkhandler, domain)
+    if not dom_uuid:
+        return False, 'ERROR: Could not find VM "{}" in the cluster!'.format(domain)
+
+    # Verify that the VM is in a stopped state; renaming is not supported otherwise
+    state = zkhandler.read(("domain.state", dom_uuid))
+    if state not in ["stop", "disable"]:
+        return (
+            False,
+            'ERROR: VM "{}" is not in stopped state; VMs cannot be rolled back while running.'.format(
+                domain
+            ),
+        )
+
+    # Verify that the snapshot exists
+    if not zkhandler.exists(
+        ("domain.snapshots", dom_uuid, "domain_snapshot.name", snapshot_name)
+    ):
+        return (
+            False,
+            f'ERROR: Could not find snapshot "{snapshot_name}" of VM "{domain}"!',
+        )
+
+    tstart = time.time()
+
+    _snapshots = zkhandler.read(
+        ("domain.snapshots", dom_uuid, "domain_snapshot.rbd_snapshots", snapshot_name)
+    )
+    rbd_snapshots = _snapshots.split(",")
+    for snap in rbd_snapshots:
+        rbd, name = snap.split("@")
+        pool, volume = rbd.split("/")
+        ret, msg = ceph.rollback_snapshot(zkhandler, pool, volume, name)
+        if not ret:
+            return False, msg
+
+    # Get the snapshot domain XML
+    vm_config = zkhandler.read(
+        ("domain.snapshots", dom_uuid, "domain_snapshot.xml", snapshot_name)
+    )
+
+    # Write the restored config to the main XML config
+    zkhandler.write(
+        [
+            (
+                (
+                    "domain.xml",
+                    dom_uuid,
+                ),
+                vm_config,
+            ),
+        ]
+    )
+
+    tend = time.time()
+    ttot = round(tend - tstart, 2)
+    return (
+        True,
+        f'Successfully rolled back to snapshot "{snapshot_name}" of VM "{domain}" in {ttot}s.',
+    )
 
 
 #