Custom YAML tag to get already existed ONAP resources properties

Would be useful for Alloted Resources

Issue-ID: INT-2075
Signed-off-by: Michal Jagiello <michal.jagiello@t-mobile.pl>
Change-Id: Iad398a2f0c049ba73fa4569a0f2caed1311f077c

9 files changed, 283 insertions, 2 deletions

diff --git a/docs/source/index.rst b/docs/source/index.rst
index 5cadde1..9360ed3 100644
--- a/docs/source/index.rst
+++ b/docs/source/index.rst
@@ -12,6 +12,7 @@ Welcome to ONAP data provider's documentation!
 
    description
    schemas
+   tags
    usage
 
 
diff --git a/docs/source/tags.rst b/docs/source/tags.rst
new file mode 100644
index 0000000..b16e83e
--- /dev/null
+++ b/docs/source/tags.rst
@@ -0,0 +1,33 @@
+ONAP data provider custom YAML tags
+===================================
+
+In ONAP data provider we created a few custom YAML tags which could be used (and useful) in entities files.
+
+!join tag
+---------
+
+Concatenate multiple strings in YAML value.
+
+`!join [a, b, c]` result is `abc`
+
+`!join ['_', [a, b, c]]` result is `a_b_c`
+
+!uuid4 tag
+----------
+
+Generates a random UUID4
+
+`!uuid4` result is random UUID4 value
+
+!onap_resource_property
+-----------------------
+
+Gets the property value from the already existing ONAP resources.
+
+Available resources:
+
+* SDC service
+
+`!onap_resource_property service identifier service-model-name` result is a SDC service "service-model-name" model "identifier" property value
+
+`!onap_resource_property service identifier service-model-name 1.0` result is a SDC service "service-model-name" version 1.0 model "identifier" property value
diff --git a/onap_data_provider/config_loader.py b/onap_data_provider/config_loader.py
index 5757e1e..4507a14 100644
--- a/onap_data_provider/config_loader.py
+++ b/onap_data_provider/config_loader.py
@@ -17,11 +17,12 @@
 from pathlib import Path
 from typing import Any, Iterator, List
 import yaml
-from onap_data_provider.tag_handlers import join, generate_random_uuid
+from onap_data_provider.tag_handlers import join, generate_random_uuid, resource_property
 
 # register custom tag handlers in yaml.SafeLoader
 yaml.add_constructor("!join", join, yaml.SafeLoader)
 yaml.add_constructor("!uuid4", generate_random_uuid, yaml.SafeLoader)
+yaml.add_constructor("!onap_resource_property", resource_property, yaml.SafeLoader)
 
 
 class ConfigLoader:
diff --git a/onap_data_provider/property_tag/__init__.py b/onap_data_provider/property_tag/__init__.py
new file mode 100644
index 0000000..1e88be1
--- /dev/null
+++ b/onap_data_provider/property_tag/__init__.py
@@ -0,0 +1,21 @@
+"""Resource property tag package.
+
+There the package modules are going to be implemented.
+Each module represents one resource which can be used with "!onap_resource_property" tag.
+
+"""
+"""
+   Copyright 2022 Deutsche Telekom AG
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+"""
\ No newline at end of file
diff --git a/onap_data_provider/property_tag/base.py b/onap_data_provider/property_tag/base.py
new file mode 100644
index 0000000..7ae7102
--- /dev/null
+++ b/onap_data_provider/property_tag/base.py
@@ -0,0 +1,73 @@
+"""Base module for property tag classes."""
+"""
+   Copyright 2022 Deutsche Telekom AG
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+"""
+
+from abc import ABC
+from typing import Any, Type
+
+from onapsdk.onap_service import OnapService  # type: ignore
+
+
+class BasePropertyTagResource(ABC):
+    """Base property tag resource class.
+
+    Abstract class which all resource classes should inherit from.
+    Subclasses has to implement `resource` property to get the valid object
+        using Python ONAP SDK classes.
+
+    Subclass could also implement `__init__` method to get more attributes from
+        the user which uses the tag.
+
+    """
+
+    def __init__(self, property_name: str) -> None:
+        """Init property tag resource object.
+
+        Args:
+            property_name (str): Name of the property to get
+
+        """
+        self.property_name: str = property_name
+
+    @property
+    def resource(self) -> OnapService:
+        """Resource property abstract method.
+
+        Returns an object from which the property is going to be get.
+
+        Raises:
+            NotImplementedError: That method is an abstract one
+
+        Returns:
+            OnapService: Any OnapService subclass
+
+        """
+        raise NotImplementedError
+
+    @property
+    def resource_property(self) -> Any:
+        """Resource property.
+
+        Using `getattr` function get the property from resource.
+
+        Returns:
+            Any: Property value
+
+        Raises:
+            AttributeError: Resource has no property with given name.
+
+        """
+        return getattr(self.resource, self.property_name)
diff --git a/onap_data_provider/property_tag/properties_getter.py b/onap_data_provider/property_tag/properties_getter.py
new file mode 100644
index 0000000..df29314
--- /dev/null
+++ b/onap_data_provider/property_tag/properties_getter.py
@@ -0,0 +1,64 @@
+"""Properties getter module."""
+"""
+   Copyright 2022 Deutsche Telekom AG
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+"""
+
+import logging
+from typing import Any, Mapping, Type, TYPE_CHECKING
+
+from .base import BasePropertyTagResource
+from .sdc_service import SdcServicePropertyTagResource
+
+if TYPE_CHECKING:
+    from typing import Any, Mapping
+
+
+class PropertiesGetter:
+    """Properties getter class.
+
+    Uses to get values of properties from already existing ONAP resources.
+
+    Contains a mapper to select right class to get the values from.
+    """
+
+    RESOURCES: Mapping[str, Type[BasePropertyTagResource]] = {
+        "service": SdcServicePropertyTagResource
+    }
+
+    @classmethod
+    def get_property(cls, resource_type: str, *args: str) -> Any:
+        """Get property class method.
+
+        Maps the input `resource_type` into `BasePropertyTagResource` class
+            and get it's `resource_property` property
+
+        Args:
+            resource_type (str): Type of the resource - uses by a mapper
+            *args (str): Args to be passed to the service class init
+
+        Raises:
+            ValueError: Given resource type is not supported
+
+        Returns:
+            Any: Resource property value
+
+        """
+        try:
+            return cls.RESOURCES[resource_type](*args).resource_property
+        except KeyError:
+            msg = f"Resource type \"{resource_type}\" is not supported"
+            logging.error(msg)
+            raise ValueError(msg)
+
diff --git a/onap_data_provider/property_tag/sdc_service.py b/onap_data_provider/property_tag/sdc_service.py
new file mode 100644
index 0000000..b8eca80
--- /dev/null
+++ b/onap_data_provider/property_tag/sdc_service.py
@@ -0,0 +1,52 @@
+"""SDC property module used by tag to get resource's property"""
+"""
+   Copyright 2022 Deutsche Telekom AG
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+"""
+
+from typing import Optional
+
+from onapsdk.onap_service import OnapService  # type: ignore
+from onapsdk.sdc.service import Service  # type: ignore
+
+from .base import BasePropertyTagResource
+
+
+class SdcServicePropertyTagResource(BasePropertyTagResource):
+    """Class to get property from SDC service module objects."""
+
+    def __init__(self, property_name: str, service_name: str, version: Optional[str] = None) -> None:
+        """Initialize object.
+
+        Get the name of the property to get, serivce name and optional version of the service.
+
+        Args:
+            property_name (str): Property name
+            service_name (str): Service name
+            version (Optional[str], optional): Optional version. If no version is given
+                the latest version of the service will be loaded. Defaults to None.
+        """
+        super().__init__(property_name)
+        self.service_name: str = service_name
+        self.version: Optional[str] = version
+
+    @property
+    def resource(self) -> Service:
+        """Service resource.
+
+        Returns:
+            Service: Service with the provided name and version.
+
+        """
+        return Service(self.service_name, version=self.version)
diff --git a/onap_data_provider/tag_handlers.py b/onap_data_provider/tag_handlers.py
index 1f8a21a..d8c9738 100644
--- a/onap_data_provider/tag_handlers.py
+++ b/onap_data_provider/tag_handlers.py
@@ -19,6 +19,8 @@ from typing import Any
 
 import yaml
 
+from .property_tag.properties_getter import PropertiesGetter
+
 
 def join(loader: yaml.SafeLoader, node: yaml.Node) -> str:
     """Concatinates the nodes fields for !join tag.
@@ -52,3 +54,23 @@ def generate_random_uuid(*_: Any) -> str:
         str: randomly generated UUID
     """
     return str(uuid.uuid4())
+
+
+def resource_property(loader: yaml.SafeLoader, node: yaml.Node) -> Any:
+    """Resource property tag method.
+
+    Constructs a scalar from the YAML node and uses `PropertiesGetter`
+        to get a property value from already existing ONAP resource.
+
+    Args:
+        loader (yaml.SafeLoader): YAML Safe Loader
+        node (yaml.Node): Node to get values from
+
+    Raises:
+        ValueError: Given property type from the node is not supported by a tag
+
+    Returns:
+        Any: Resource's property value
+    """
+    resource_type, *args = loader.construct_scalar(node).split(" ")  # type: ignore
+    return PropertiesGetter.get_property(resource_type, *args)
diff --git a/tests/test_tag_handlers.py b/tests/test_tag_handlers.py
index 719295f..c7c9ffc 100644
--- a/tests/test_tag_handlers.py
+++ b/tests/test_tag_handlers.py
@@ -1,5 +1,8 @@
 from unittest.mock import patch, PropertyMock
-from onap_data_provider.tag_handlers import join, generate_random_uuid
+
+import pytest
+
+from onap_data_provider.tag_handlers import join, generate_random_uuid, resource_property
 
 
 def test_generate_random_uuid():
@@ -13,3 +16,14 @@ def test_generate_random_uuid():
 def test_join(mock_safe_loader):
     mock_safe_loader.construct_sequence.return_value = ["-", ["cloud", "owner", "DC1"]]
     assert join(mock_safe_loader, None) == "cloud-owner-DC1"
+
+
+@patch("yaml.SafeLoader", new_callable=PropertyMock)
+@patch("onap_data_provider.property_tag.sdc_service.Service")
+def test_resource_property(mock_service, mock_safe_loader):
+    mock_safe_loader.construct_scalar.return_value = "unknown"
+    with pytest.raises(ValueError, match="Resource type \"unknown\" is not supported"):
+        resource_property(mock_safe_loader, None)
+    mock_service.return_value.identifier = "123"
+    mock_safe_loader.construct_scalar.return_value = "service identifier test_name"
+    assert resource_property(mock_safe_loader, None) == "123"