[pve-devel] [PATCH v1 pve-esxi-import-tools 3/5] listvms: improve typing and add dataclasses to represent dicts
Lukas Wagner
l.wagner at proxmox.com
Wed Mar 20 10:38:42 CET 2024
On 2024-03-19 16:32, Max Carrara wrote:
> This commit replaces some of the explicitly imported types from the
> `typing` module with their inbuilt counterparts, e.g. `typing.List`
> becomes `list`. This is supported since Python 3.9 [0].
>
> Additionally, file paths are now represented as `pathlib.Path` [1],
> which also checks whether the given string is actually a valid path
> when constructed.
>
> Furthermore, the `dict`s with values of mixed types are now
> represented as dataclasses [2] instead, in order to make them more
> type-safe (--> allow for better linting).
>
> Because dataclasses and `pathlib.Path`s are not JSON-serializable by
> default however, a helper function is added, which allows for more
> fine-grained control regarding how those objects are serialized.
>
> [0]: https://docs.python.org/3.9/whatsnew/3.9.html#type-hinting-generics-in-standard-collections
> [1]: https://docs.python.org/3.11/library/pathlib.html
> [2]: https://docs.python.org/3.11/library/dataclasses.html
>
> Signed-off-by: Max Carrara <m.carrara at proxmox.com>
> ---
> listvms.py | 99 ++++++++++++++++++++++++++++++++++++++++--------------
> 1 file changed, 73 insertions(+), 26 deletions(-)
>
> diff --git a/listvms.py b/listvms.py
> index cc3209f..cdea95a 100755
> --- a/listvms.py
> +++ b/listvms.py
> @@ -1,26 +1,69 @@
> #!/usr/bin/python3
>
> +import dataclasses
> import json
> import ssl
> import sys
>
> -from typing import List, Dict, Optional, Tuple
> +from dataclasses import dataclass
> +from pathlib import Path
> +from typing import Any
>
> from pyVim.connect import SmartConnect, Disconnect
> from pyVmomi import vim
>
>
> -def get_datacenter_of_vm(vm: vim.VirtualMachine) -> Optional[vim.Datacenter]:
> + at dataclass
> +class VmVmxInfo:
> + datastore: str
> + path: Path
> + checksum: str
> +
> +
> + at dataclass
> +class VmDiskInfo:
> + datastore: str
> + path: Path
> + capacity: int
> +
> +
> + at dataclass
> +class VmInfo:
> + config: VmVmxInfo
> + disks: list[VmDiskInfo]
> + power: str
> +
> +
> +def json_dump_helper(obj: Any) -> Any:
> + """Converts otherwise unserializable objects to types that can be
> + serialized as JSON.
> +
> + Raises:
> + TypeError: If the conversion of the object is not supported.
> + """
> + if dataclasses.is_dataclass(obj):
> + return dataclasses.asdict(obj)
> +
> + match obj:
> + case Path():
> + return str(obj)
> +
> + raise TypeError(
> + f"Can't make object of type {type(obj)} JSON-serializable: {repr(obj)}"
> + )
> +
> +
> +def get_datacenter_of_vm(vm: vim.VirtualMachine) -> vim.Datacenter | None:
> """Find the Datacenter object a VM belongs to."""
> current = vm.parent
> while current:
> if isinstance(current, vim.Datacenter):
> return current
> current = current.parent
> - return None
> + return
mypy does not seem to like this change :)
listvms.py:157: error: Return value expected [return-value]
>
>
> -def list_vms(service_instance: vim.ServiceInstance) -> List[vim.VirtualMachine]:
> +def list_vms(service_instance: vim.ServiceInstance) -> list[vim.VirtualMachine]:
> """List all VMs on the ESXi/vCenter server."""
> content = service_instance.content
> vm_view = content.viewManager.CreateContainerView(
> @@ -32,39 +75,36 @@ def list_vms(service_instance: vim.ServiceInstance) -> List[vim.VirtualMachine]:
> vm_view.Destroy()
> return vms
>
> -def parse_file_path(path):
> +def parse_file_path(path) -> tuple[str, Path]:
> """Parse a path of the form '[datastore] file/path'"""
> datastore_name, relative_path = path.split('] ', 1)
> datastore_name = datastore_name.strip('[')
> - return (datastore_name, relative_path)
> + return (datastore_name, Path(relative_path))
>
> -def get_vm_vmx_info(vm: vim.VirtualMachine) -> Dict[str, str]:
> +def get_vm_vmx_info(vm: vim.VirtualMachine) -> VmVmxInfo:
> """Extract VMX file path and checksum from a VM object."""
> datastore_name, relative_vmx_path = parse_file_path(vm.config.files.vmPathName)
> - return {
> - 'datastore': datastore_name,
> - 'path': relative_vmx_path,
> - 'checksum': vm.config.vmxConfigChecksum.hex() if vm.config.vmxConfigChecksum else 'N/A'
> - }
>
> -def get_vm_disk_info(vm: vim.VirtualMachine) -> Dict[str, int]:
> + return VmVmxInfo(
> + datastore=datastore_name,
> + path=relative_vmx_path,
> + checksum=vm.config.vmxConfigChecksum.hex() if vm.config.vmxConfigChecksum else 'N/A'
> + )
> +
> +def get_vm_disk_info(vm: vim.VirtualMachine) -> list[VmDiskInfo]:
> disks = []
> for device in vm.config.hardware.device:
> - if type(device).__name__ == 'vim.vm.device.VirtualDisk':
> + if isinstance(device, vim.vm.device.VirtualDisk):
> try:
> (datastore, path) = parse_file_path(device.backing.fileName)
> capacity = device.capacityInBytes
> - disks.append({
> - 'datastore': datastore,
> - 'path': path,
> - 'capacity': capacity,
> - })
> + disks.append(VmDiskInfo(datastore, path, capacity))
> except Exception as err:
> # if we can't figure out the disk stuff that's fine...
> print("failed to get disk information for esxi vm: ", err, file=sys.stderr)
> return disks
>
> -def get_all_datacenters(service_instance: vim.ServiceInstance) -> List[vim.Datacenter]:
> +def get_all_datacenters(service_instance: vim.ServiceInstance) -> list[vim.Datacenter]:
> """Retrieve all datacenters from the ESXi/vCenter server."""
> content = service_instance.content
> dc_view = content.viewManager.CreateContainerView(content.rootFolder, [vim.Datacenter], True)
> @@ -107,18 +147,25 @@ def main():
> name = 'vm ' + vm.name
> try:
> dc = get_datacenter_of_vm(vm)
> - vm_info = {
> - 'config': get_vm_vmx_info(vm),
> - 'disks': get_vm_disk_info(vm),
> - 'power': vm.runtime.powerState,
> - }
> + if dc is None:
> + print(
> + f"Failed to get datacenter for {name}",
> + file=sys.stderr
> + )
> +
> + vm_info = VmInfo(
> + config=get_vm_vmx_info(vm),
> + disks=get_vm_disk_info(vm),
> + power=vm.runtime.powerState,
> + )
> +
> datastore_info = {ds.name: ds.url for ds in vm.config.datastoreUrl}
> data.setdefault(dc.name, {}).setdefault('vms', {})[vm.name] = vm_info
> data.setdefault(dc.name, {}).setdefault('datastores', {}).update(datastore_info)
> except Exception as err:
> print("failed to get info for", name, ':', err, file=sys.stderr)
>
> - print(json.dumps(data, indent=2))
> + print(json.dumps(data, indent=2, default=json_dump_helper))
I guess this could be
`json.dump(data, sys.stdout, ...)`
That'd not add a newline in the end, not sure if that is important here.
But it really does not matter that much, I guess. ;)
> finally:
> Disconnect(si)
>
--
- Lukas
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