Improve path handling, other small refactorings (Azure#39)

# Main changes

## Make methods relying on self._tmp_dir private
- `self._tmp_dir` is only available in the context of calling `generate_nfd()`, so methods relying on `self._tmp_dir` should be private

## Use pathlib.Path rather than os file operations
- Provides clearer and stronger typing than passing `str`s around
- Adds some handy utility functions

## Variable renaming for clarity
- E.g. consistently use 'directory' / 'dir' (rather than mix with 'folder')
- Obvs somewhat subjective, but as someone new to most of this code, the changes made sense to me

## Add nfd_bicep_path as abstract property on NFDGenerator
- We rely on it when calling the concrete implementations
- Also use ABC rather than raise NotImplementedError

## Miscellaneous style updates to keep `azdev style aosm` happy
- isort
- black

src/aosm/azext_aosm/_configuration.py

@@ -13,7 +13,7 @@
     NSD,
     NSD_OUTPUT_BICEP_PREFIX,
     VNF,
-    SOURCE_ACR_REGEX
+    SOURCE_ACR_REGEX,
 )
 
 DESCRIPTION_MAP: Dict[str, str] = {
@@ -229,7 +229,7 @@ def network_function_name(self) -> str:
     @property
     def acr_manifest_name(self) -> str:
         """Return the ACR manifest name from the NFD name."""
-        sanitised_nf_name = self.network_function_name.lower().replace('_', '-')
+        sanitised_nf_name = self.network_function_name.lower().replace("_", "-")
         return (
             f"{sanitised_nf_name}-nsd-acr-manifest-{self.nsd_version.replace('.', '-')}"
         )
@@ -329,10 +329,10 @@ def sa_manifest_name(self) -> str:
         return f"{sanitized_nf_name}-sa-manifest-{self.version.replace('.', '-')}"
 
     @property
-    def build_output_folder_name(self) -> str:
+    def output_directory_for_build(self) -> Path:
         """Return the local folder for generating the bicep template to."""
-        arm_template_path = self.arm_template.file_path
-        return f"{NF_DEFINITION_OUTPUT_BICEP_PREFIX}{Path(str(arm_template_path)).stem}"
+        arm_template_name = Path(self.arm_template.file_path).stem
+        return Path(f"{NF_DEFINITION_OUTPUT_BICEP_PREFIX}{arm_template_name}")
 
 
 @dataclass
@@ -362,9 +362,9 @@ def __post_init__(self):
                 self.helm_packages[package_index] = HelmPackageConfig(**dict(package))
 
     @property
-    def build_output_folder_name(self) -> str:
-        """Return the local folder for generating the bicep template to."""
-        return f"{NF_DEFINITION_OUTPUT_BICEP_PREFIX}{self.nf_name}"
+    def output_directory_for_build(self) -> Path:
+        """Return the directory the build command will writes its output to"""
+        return Path(f"{NF_DEFINITION_OUTPUT_BICEP_PREFIX}{self.nf_name}")
 
     def validate(self):
         """Validate the CNF config
@@ -379,7 +379,9 @@ def validate(self):
         if not source_registry_match or len(source_registry_match.groups()) < 2:
             raise ValidationError(
                 "CNF config has an invalid source registry ID. Please run `az aosm "
-                "nfd generate-config` to see the valid formats.")
+                "nfd generate-config` to see the valid formats."
+            )
+
 
 def get_configuration(
     configuration_type: str, config_as_dict: Optional[Dict[Any, Any]] = None

src/aosm/azext_aosm/custom.py

@@ -7,6 +7,7 @@
 import os
 import shutil
 from dataclasses import asdict
+from pathlib import Path
 from typing import Optional
 
 from azure.cli.core.azclierror import (
@@ -116,15 +117,15 @@ def _generate_nfd(
             "Generate NFD called for unrecognised definition_type. Only VNF and CNF"
             " have been implemented."
         )
-    if nfd_generator.bicep_path:
+    if nfd_generator.nfd_bicep_path:
         carry_on = input(
-            f"The folder {os.path.dirname(nfd_generator.bicep_path)} already exists -"
+            f"The {nfd_generator.nfd_bicep_path.parent} directory already exists -"
             " delete it and continue? (y/n)"
         )
         if carry_on != "y":
-            raise UnclassifiedUserFault("User aborted! ")
+            raise UnclassifiedUserFault("User aborted!")
 
-        shutil.rmtree(os.path.dirname(nfd_generator.bicep_path))
+        shutil.rmtree(nfd_generator.nfd_bicep_path.parent)
     nfd_generator.generate_nfd()
 
 
@@ -177,7 +178,7 @@ def publish_definition(
             parameters_json_file=parameters_json_file,
             manifest_bicep_path=manifest_file,
             manifest_parameters_json_file=manifest_parameters_json_file,
-            skip=skip
+            skip=skip,
         )
     elif definition_type == CNF:
         deployer = DeployerViaArm(api_clients, config=config)
@@ -187,7 +188,7 @@ def publish_definition(
             parameters_json_file=parameters_json_file,
             manifest_bicep_path=manifest_file,
             manifest_parameters_json_file=manifest_parameters_json_file,
-            skip=skip
+            skip=skip,
         )
     else:
         raise ValueError(
@@ -253,7 +254,7 @@ def _generate_config(configuration_type: str, output_file: str = "input.json"):
     config = get_configuration(configuration_type)
     config_as_dict = json.dumps(asdict(config), indent=4)
 
-    if os.path.exists(output_file):
+    if Path(output_file).exists():
         carry_on = input(
             f"The file {output_file} already exists - do you want to overwrite it?"
             " (y/n)"
@@ -369,7 +370,7 @@ def publish_design(
         parameters_json_file=parameters_json_file,
         manifest_bicep_path=manifest_file,
         manifest_parameters_json_file=manifest_parameters_json_file,
-        skip=skip
+        skip=skip,
     )
 
 

src/aosm/azext_aosm/deploy/artifact.py

@@ -5,10 +5,12 @@
 """A module to handle interacting with artifacts."""
 import subprocess
 from dataclasses import dataclass
-from typing import Union, List
+from typing import List, Union
 
 from azure.cli.core.commands import LongRunningOperation
-from azure.mgmt.containerregistry.models import ImportImageParameters, ImportSource
+from azure.mgmt.containerregistry import ContainerRegistryManagementClient
+from azure.mgmt.containerregistry.models import (ImportImageParameters,
+                                                 ImportSource)
 from azure.storage.blob import BlobClient, BlobType
 from knack.log import get_logger
 from knack.util import CLIError
@@ -157,7 +159,7 @@ def copy_image(
         :param source_image: source image
         :param target_registry_resource_group_name: target registry resource group name
         :param target_registry_name: target registry name
-        :param target_tags: the list of tags to be applied to the imported image 
+        :param target_tags: the list of tags to be applied to the imported image
                             should be of form: namepace/name:tag or name:tag
         :param mode: mode for import
         """

src/aosm/azext_aosm/deploy/deploy_with_arm.py

@@ -5,7 +5,6 @@
 """Contains class for deploying generated definitions using ARM."""
 import json
 import os
-import re
 import shutil
 import subprocess  # noqa
 import tempfile
@@ -37,7 +36,6 @@
     VNF,
     VNF_DEFINITION_BICEP_TEMPLATE_FILENAME,
     VNF_MANIFEST_BICEP_TEMPLATE_FILENAME,
-    SOURCE_ACR_REGEX,
 )
 from azext_aosm.util.management_clients import ApiClients
 
@@ -120,7 +118,7 @@ def deploy_vnfd_from_bicep(
                 # User has not passed in a bicep template, so we are deploying the default
                 # one produced from building the NFDV using this CLI
                 bicep_path = os.path.join(
-                    self.config.build_output_folder_name,
+                    self.config.output_directory_for_build,
                     VNF_DEFINITION_BICEP_TEMPLATE_FILENAME,
                 )