Splitted hostgroup generation logic into its seperate module. Changed hostgroup "dev_role" to "role" for VM role prepration. Started work on basic VM class.

modules/hostgroups.py

@@ -0,0 +1,146 @@
+"""Module for all hostgroup related code"""
+from modules.exceptions import HostgroupError
+from modules.tools import build_path
+
+class Hostgroup():
+    """Hostgroup class for devices and VM's
+    Takes type (vm or dev) and NB object"""
+    def __init__(self, obj_type, nb_obj, version,
+                 nested_sitegroup_flag, nested_region_flag,
+                 nb_groups, nb_regions):
+        if obj_type not in ("vm", "dev"):
+            raise HostgroupError(f"Unable to create hostgroup with type {type}")
+        self.type = str(obj_type)
+        self.nb = nb_obj
+        self.name = self.nb.name
+        self.nb_version = version
+        # Used for nested data objects
+        self.nested_objects = {"site_group": {"flag": nested_sitegroup_flag, "data": nb_groups},
+                               "region": {"flag": nested_region_flag, "data": nb_regions}}
+        self._set_format_options()
+
+    def __str__(self):
+        return f"Hostgroup for {self.type} {self.name}"
+
+    def __repr__(self):
+        return self.__str__()
+
+    def _set_format_options(self):
+        """
+        Set all available variables
+        for hostgroup generation
+        """
+        format_options = {}
+        # Set variables for both type of devices
+        if self.type in ("vm", "dev"):
+            # Role fix for Netbox <=3
+            role = None
+            if self.nb_version.startswith(("2", "3")) and self.type == "dev":
+                role = self.nb.device_role.name
+            else:
+                role = self.nb.role.name
+            # Add default formatting options
+            # Check if a site is configured. A site is optional for VMs
+            format_options["region"] = None
+            format_options["location"] = None
+            format_options["site_group"] = None
+            if self.nb.site:
+                if self.nb.site.region:
+                    format_options["region"] = self.generate_parents("region",
+                                                                     str(self.nb.site.region))
+                if self.nb.location:
+                    format_options["location"] = str(self.nb.location)
+                if self.nb.site.group:
+                    format_options["site_group"] = self.generate_parents("site_group",
+                                                                         str(self.nb.site.group))
+            format_options["role"] = role
+            format_options["site"] = self.nb.site.name if self.nb.site else None
+            format_options["tenant"] = str(self.nb.tenant) if self.nb.tenant else None
+            format_options["tenant_group"] = str(self.tenant.group) if self.nb.tenant else None
+            format_options["platform"] = self.nb.platform.name if self.nb.platform else None
+        # Variables only applicable for devices
+        if self.type == "dev":
+            format_options["manufacturer"] = self.nb.device_type.manufacturer.name
+        # Variables only applicable for VM's
+        if self.type == "vm":
+            format_options["cluster"] = str(self.nb.cluster.name) if self.nb.cluster else None
+        self.format_options = format_options
+
+    def generate(self, hg_format=None):
+        """Generate hostgroup based on a provided format"""
+        # Set format to default in case its not specified
+        if not hg_format:
+            hg_format = "site/manufacturer/role" if self.type == "dev" else "cluster/role"
+        # Split all given names
+        hg_output = list()
+        hg_items = hg_format.split("/")
+        for hg_item in hg_items:
+            # Check if requested data is available as option for this host
+            if hg_item not in self.format_options:
+                # Check if a custom field exists with this name
+                cf_data = self.custom_field_lookup(hg_item)
+                # CF does not exist
+                if not cf_data["result"]:
+                    raise HostgroupError(f"Unable to generate hostgroup for host {self.name}. "
+                                         f"Item type {hg_item} not supported.")
+                # CF data is populated
+                if cf_data["cf"]:
+                    hg_output.append(cf_data["cf"])
+                continue
+            # Check if there is a value associated to the variable.
+            # For instance, if a device has no location, do not use it with hostgroup calculation
+            hostgroup_value = self.format_options[hg_item]
+            if hostgroup_value:
+                hg_output.append(hostgroup_value)
+        # Check if the hostgroup is populated with at least one item.
+        if bool(hg_output):
+            return "/".join(hg_output)
+        raise HostgroupError(f"Unable to generate hostgroup for host {self.name}."
+                             "Not enough valid items. This is most likely"
+                             "due to the use of custom fields that are empty.")
+
+    def list_formatoptions(self):
+        """
+        Function to easily troubleshoot which values
+        are generated for a specific device or VM.
+        """
+        print(f"The following options are available for host {self.name}")
+        for option_type, value in self.format_options.items():
+            if value is not None:
+                print(f"{option_type} - {value}")
+        print("The following options are not available")
+        for option_type, value in self.format_options.items():
+            if value is None:
+                print(f"{option_type}")
+
+    def custom_field_lookup(self, hg_category):
+        """
+        Checks if a valid custom field is present in Netbox.
+        INPUT: Custom field name
+        OUTPUT: dictionary with 'result' and 'cf' keys.
+        """
+        # Check if the custom field exists
+        if hg_category not in self.nb.custom_fields:
+            return {"result": False, "cf": None}
+        # Checks if the custom field has been populated
+        if not bool(self.nb.custom_fields[hg_category]):
+            return {"result": True, "cf": None}
+        # Custom field exists and is populated
+        return {"result": True, "cf": self.nb.custom_fields[hg_category]}
+
+    def generate_parents(self, nest_type, child_object):
+        """
+        Generates parent objects to implement nested regions / nested site groups
+        INPUT: nest_type to set which type of nesting is going to be processed
+        child_object: the name of the child object (for instance the last NB region)
+        OUTPUT: STRING - Either the single child name or child and parents.
+        """
+        # Check if this type of nesting is supported.
+        if not nest_type in self.nested_objects:
+            return child_object
+        # If the nested flag is True, perform parent calculation
+        if self.nested_objects[nest_type]["flag"]:
+            final_nested_object = build_path(child_object, self.nested_objects[nest_type]["data"])
+            return "/".join(final_nested_object)
+        # Nesting is not allowed for this object. Return child_object
+        return child_object