Add VM snapshots functionality

Adds the ability to create snapshots of an entire VM, including all its
RBD disks and the VM XML config, though not any PVC metadata.

client-cli/pvc/cli/cli.py

@@ -1765,6 +1765,53 @@ def cli_vm_flush_locks(domain, wait_flag):
     finish(retcode, retmsg)
 
 
+###############################################################################
+# > pvc vm snapshot
+###############################################################################
+@click.group(
+    name="snapshot",
+    short_help="Manage snapshots for PVC VMs.",
+    context_settings=CONTEXT_SETTINGS,
+)
+def cli_vm_snapshot():
+    """
+    Manage snapshots of VMs in a PVC cluster.
+    """
+    pass
+
+
+###############################################################################
+# > pvc vm snapshot create
+###############################################################################
+@click.command(name="create", short_help="Create a snapshot of a virtual machine.")
+@connection_req
+@click.argument("domain")
+@click.argument("snapshot_name", required=False, default=None)
+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 mayb e a UUID or name.
+
+    WARNING: RBD snapshots are crash-consistent but not filesystem-aware. If a snapshot was taken
+    of a running VM, restoring that snapshot will be equivalent to having forcibly restarted the
+    VM at the moment of the snapshot.
+    """
+
+    echo(
+        CLI_CONFIG,
+        f"Taking snapshot of VM '{domain}'... ",
+        newline=False,
+    )
+    retcode, retmsg = pvc.lib.vm.vm_create_snapshot(
+        CLI_CONFIG, domain, snapshot_name=snapshot_name
+    )
+    if retcode:
+        echo(CLI_CONFIG, "done.")
+    else:
+        echo(CLI_CONFIG, "failed.")
+    finish(retcode, retmsg)
+
+
 ###############################################################################
 # > pvc vm backup
 ###############################################################################
@@ -6302,6 +6349,8 @@ cli_vm.add_command(cli_vm_move)
 cli_vm.add_command(cli_vm_migrate)
 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.add_command(cli_vm_snapshot)
 cli_vm_backup.add_command(cli_vm_backup_create)
 cli_vm_backup.add_command(cli_vm_backup_restore)
 cli_vm_backup.add_command(cli_vm_backup_remove)

client-cli/pvc/lib/vm.py

@@ -498,6 +498,27 @@ def vm_restore(config, vm, backup_path, backup_datestring, retain_snapshot=False
         return True, response.json().get("message", "")
 
 
+def vm_create_snapshot(config, vm, snapshot_name=None):
+    """
+    Take a snapshot of a VM's disks and configuration
+
+    API endpoint: POST /vm/{vm}/snapshot
+    API arguments: snapshot_name=snapshot_name
+    API schema: {"message":"{data}"}
+    """
+    params = dict()
+    if snapshot_name is not None:
+        params["snapshot_name"] = snapshot_name
+    response = call_api(
+        config, "post", "/vm/{vm}/snapshot".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