Add branch parameter to generate intended config view

changes/828.added

@@ -0,0 +1 @@
+Added `branch` parameter to generate intended config view.

docs/user/app_feature_intended.md

@@ -35,26 +35,36 @@ In these examples, `/services.j2`, `/ntp.j2`, etc. could contain the actual Jinj
 
 ### Developing Intended Configuration Templates
 
-To help developers create the Jinja2 templates for generating a device's intended configuration, the app provides a REST API at `/api/plugins/golden-config/generate-intended-config/` and a simple web UI at `/plugins/golden-config/generate-intended-config/`. The REST API accepts a query parameter for `device_id` and returns the rendered configuration for the specified device using the templates from the device's golden config `jinja_repository` Git repository. This feature allows developers to test their configuration templates without running a full "intended configuration" job.
+To generate a device's intended configuration without running a full "intended configuration" job, Golden Config provides a simple web UI at `/plugins/golden-config/generate-intended-config/` and a REST API at `/api/plugins/golden-config/generate-intended-config/`. 
 
-Here's an example of how to request the rendered configuration for a device using the REST API:
+Note that this tool is only intended to render Jinja2 templates and does not apply any [configuration post-processing](./app_feature_config_postprocessing.md).
 
-```no-highlight
-curl -s -X GET \
-    -H "Accept: application/json" \
-    http://nautobot/api/plugins/golden-config/generate-intended-config/?device_id=231b8765-054d-4abe-bdbf-cd60e049cd8d
-```
+Using this tool to render a configuration will automatically retrieve the latest commit from the Jinja2 templates Git repository before rendering the template.
+
+#### Web UI
 
-The returned response will contain the rendered configuration for the specified device, the GraphQL data that was used, and if applicable, a diff of the most recent intended config that was generated by the **Intended Configuration** job. The web UI provides a simple form to interact with this REST API. You can access the web UI by clicking on "Generate Intended Config" in the "Tools" section of the Golden Config navigation menu.
+The web UI provides a user-friendly form to interact with the rendering process. You can access the web UI by clicking on "Generate Intended Config" in the "Tools" section of the Golden Config navigation menu.
 
-For more advanced use cases, the REST API and web UI also accept a `graphql_query_id` parameter to specify a custom GraphQL query to use when rendering the configuration. If a `graphql_query_id` is not provided, the default query configured in the Device's Golden Config settings will be used.
+For more advanced use cases, the form accepts an optional "GraphQL Query" to specify a custom GraphQL query to use when rendering the configuration. If a "GraphQL Query" is not provided, the default query configured in the Device's Golden Config settings will be used.
+
+Starting in Nautobot v2.4.2, this UI also allows you to supply a "Git Repository Branch" to specify the branch of the Jinja2 templates Git repository to use when rendering the configuration. If the branch is not provided, the configured branch of the Golden Config Setting's Jinja template Git repository will be used.
 
 ![Intended Configuration Web UI](../images/generate-intended-config-ui.png#only-light)
 ![Intended Configuration Web UI](../images/generate-intended-config-ui-dark.png#only-dark)
 
-Calling this API endpoint automatically performs a `git pull`, retrieving the latest commit from the Jinja2 templates Git repository before rendering the template.
+#### REST API
+
+The REST API accepts query parameters for `device_id`, an optional `graphql_query_id` and an optional `branch` if running Nautobot v2.4.2 or later.
+
+Here's an example of how to request the rendered configuration for a device using the REST API:
+
+```no-highlight
+curl -s -X GET \
+    -H "Accept: application/json" \
+    http://nautobot/api/plugins/golden-config/generate-intended-config/?device_id=231b8765-054d-4abe-bdbf-cd60e049cd8d
+```
 
-Note that this API is only intended to render Jinja2 templates and does not apply any [configuration post-processing](./app_feature_config_postprocessing.md).
+The returned response will contain the rendered configuration for the specified device, the GraphQL data that was used, and if applicable, a diff of the most recent intended config that was generated by the **Intended Configuration** job.
 
 ## Adding Jinja2 Filters to the Environment.
 

nautobot_golden_config/api/serializers.py

@@ -2,8 +2,12 @@
 
 # pylint: disable=too-many-ancestors
 from nautobot.apps.api import NautobotModelSerializer, TaggedModelSerializerMixin
+from nautobot.apps.utils import GitRepo
 from nautobot.dcim.api.serializers import DeviceSerializer
 from nautobot.dcim.models import Device
+from nautobot.extras.api.serializers import GitRepositorySerializer
+from nautobot.extras.datasources.git import ensure_git_repository, get_repo_from_url_to_path_and_from_branch
+from nautobot.extras.models import GitRepository
 from rest_framework import serializers
 
 from nautobot_golden_config import models
@@ -136,3 +140,25 @@ class GenerateIntendedConfigSerializer(serializers.Serializer):  # pylint: disab
     graphql_data = serializers.JSONField(read_only=True)
     diff = serializers.CharField(read_only=True)
     diff_lines = serializers.ListField(read_only=True, child=serializers.CharField())
+
+
+class GitRepositoryWithBranchesSerializer(GitRepositorySerializer):  # pylint: disable=nb-sub-class-name
+    """Serializer for extras.GitRepository with remote branches field."""
+
+    remote_branches = serializers.SerializerMethodField()
+
+    def get_remote_branches(self, obj):
+        """Return a list of branches for the GitRepository."""
+        ensure_git_repository(obj)
+        from_url, to_path, _ = get_repo_from_url_to_path_and_from_branch(obj)
+        repo_helper = GitRepo(to_path, from_url)
+        repo_helper.repo.remotes.origin.fetch()
+        return [
+            ref.name[7:]  # removeprefix("origin/")
+            for ref in repo_helper.repo.remotes.origin.refs
+            if ref.name != "origin/HEAD"
+        ]
+
+    class Meta:  # noqa: D106  # undocumented-public-nested-class
+        model = GitRepository
+        fields = "__all__"

nautobot_golden_config/api/urls.py

@@ -30,5 +30,10 @@
         views.GenerateIntendedConfigView.as_view(),
         name="generate_intended_config",
     ),
+    path(
+        "git-repository-branches/<pk>/",
+        views.GitRepositoryBranchesView.as_view(),
+        name="git_repository_branches",
+    ),
 ]
 urlpatterns += router.urls

nautobot_golden_config/api/views.py

@@ -6,6 +6,7 @@
 import logging
 from pathlib import Path
 
+from django.conf import settings as nautobot_settings
 from django.contrib.contenttypes.models import ContentType
 from django.utils.timezone import make_aware
 from drf_spectacular.types import OpenApiTypes
@@ -21,13 +22,14 @@
 )
 from nautobot.dcim.models import Device
 from nautobot.extras.datasources.git import ensure_git_repository
-from nautobot.extras.models import GraphQLQuery
+from nautobot.extras.models import GitRepository, GraphQLQuery
 from nautobot_plugin_nornir.constants import NORNIR_SETTINGS
 from nornir import InitNornir
 from nornir_nautobot.plugins.tasks.dispatcher import dispatcher
+from packaging import version
 from rest_framework import mixins, status, viewsets
 from rest_framework.exceptions import APIException
-from rest_framework.generics import GenericAPIView
+from rest_framework.generics import GenericAPIView, RetrieveAPIView
 from rest_framework.mixins import DestroyModelMixin, ListModelMixin, RetrieveModelMixin, UpdateModelMixin
 from rest_framework.permissions import AllowAny, BasePermission, IsAuthenticated
 from rest_framework.response import Response
@@ -237,20 +239,29 @@ def _get_object(self, request, model, query_param):
         except model.DoesNotExist as exc:
             raise GenerateIntendedConfigException(f"{model.__name__} with id '{pk}' not found") from exc
 
-    def _get_jinja_template_path(self, settings, device, git_repository):
+    def _get_jinja_template_path(self, settings, device, git_repository, base_path=None):
         """Get the Jinja template path for the device in the provided git repository."""
         try:
             rendered_path = render_jinja2(template_code=settings.jinja_path_template, context={"obj": device})
         except (TemplateSyntaxError, TemplateError) as exc:
             raise GenerateIntendedConfigException("Error rendering Jinja path template") from exc
-        filesystem_path = Path(git_repository.filesystem_path) / rendered_path
+        if base_path is None:
+            filesystem_path = Path(git_repository.filesystem_path) / rendered_path
+        else:
+            filesystem_path = Path(base_path) / rendered_path
         if not filesystem_path.is_file():
-            msg = f"Jinja template {filesystem_path} not found in git repository {git_repository}"
+            msg = f"Jinja template {rendered_path} not found in git repository {git_repository}"
             raise GenerateIntendedConfigException(msg)
         return filesystem_path
 
     @extend_schema(
         parameters=[
+            OpenApiParameter(
+                name="branch",
+                required=False,
+                type=OpenApiTypes.STR,
+                location=OpenApiParameter.QUERY,
+            ),
             OpenApiParameter(
                 name="device_id",
                 required=True,
@@ -265,9 +276,12 @@ def _get_jinja_template_path(self, settings, device, git_repository):
             ),
         ]
     )
-    def get(self, request, *args, **kwargs):
+    def get(self, request, *args, **kwargs):  # pylint: disable=too-many-locals, too-many-branches
         """Generate intended configuration for a Device."""
         device = self._get_object(request, Device, "device_id")
+        branch_param = request.query_params.get("branch")
+        if branch_param and version.parse(nautobot_settings.VERSION) < version.parse("2.4.2"):
+            raise GenerateIntendedConfigException("Branch support requires Nautobot v2.4.2 or later")
         graphql_query = None
         graphql_query_id_param = request.query_params.get("graphql_query_id")
         if graphql_query_id_param:
@@ -298,17 +312,28 @@ def get(self, request, *args, **kwargs):
         except Exception as exc:
             raise GenerateIntendedConfigException("Error trying to sync git repository") from exc
 
-        filesystem_path = self._get_jinja_template_path(settings, device, git_repository)
-
         status_code, graphql_data = graph_ql_query(request, device, graphql_query.query)
         if status_code == status.HTTP_200_OK:
             try:
-                intended_config = self._render_config_nornir_serial(
-                    device=device,
-                    jinja_template=filesystem_path.name,
-                    jinja_root_path=filesystem_path.parent,
-                    graphql_data=graphql_data,
-                )
+                if branch_param:
+                    with git_repository.clone_to_directory_context(branch=branch_param) as git_repo_path:
+                        filesystem_path = self._get_jinja_template_path(
+                            settings, device, git_repository, base_path=git_repo_path
+                        )
+                        intended_config = self._render_config_nornir_serial(
+                            device=device,
+                            jinja_template=filesystem_path.name,
+                            jinja_root_path=filesystem_path.parent,
+                            graphql_data=graphql_data,
+                        )
+                else:
+                    filesystem_path = self._get_jinja_template_path(settings, device, git_repository)
+                    intended_config = self._render_config_nornir_serial(
+                        device=device,
+                        jinja_template=filesystem_path.name,
+                        jinja_root_path=filesystem_path.parent,
+                        graphql_data=graphql_data,
+                    )
             except Exception as exc:
                 raise GenerateIntendedConfigException(f"Error rendering Jinja template: {exc}") from exc
 
@@ -372,3 +397,18 @@ def _render_config_nornir_serial(self, device, jinja_template, jinja_root_path,
                     )
             else:
                 return results[device.name][1][1][0].result["config"]
+
+
+@extend_schema(exclude=True)
+class GitRepositoryBranchesView(NautobotAPIVersionMixin, RetrieveAPIView):
+    """API view for extras.GitRepository with branches."""
+
+    name = "Git Repository with Branches"
+    permission_classes = [IsAuthenticated]
+    queryset = GitRepository.objects.all()
+    serializer_class = serializers.GitRepositoryWithBranchesSerializer
+
+    def get_queryset(self):
+        """Override the original get_queryset to apply permissions."""
+        queryset = super().get_queryset()
+        return queryset.restrict(self.request.user, "view")

nautobot_golden_config/forms.py

@@ -4,11 +4,13 @@
 import json
 
 import django.forms as django_forms
+from django.conf import settings
 from nautobot.apps import forms
 from nautobot.dcim.models import Device, DeviceType, Location, Manufacturer, Platform, Rack, RackGroup
 from nautobot.extras.forms import NautobotBulkEditForm, NautobotFilterForm, NautobotModelForm
 from nautobot.extras.models import DynamicGroup, GitRepository, GraphQLQuery, JobResult, Role, Status, Tag
 from nautobot.tenancy.models import Tenant, TenantGroup
+from packaging import version
 
 from nautobot_golden_config import models
 from nautobot_golden_config.choices import ComplianceRuleConfigTypeChoice, ConfigPlanTypeChoice, RemediationTypeChoice
@@ -614,3 +616,10 @@ class GenerateIntendedConfigForm(django_forms.Form):
         label="GraphQL Query",
         query_params={"nautobot_golden_config_graphql_query_variables": "device_id"},
     )
+    git_repository_branch = django_forms.ChoiceField(widget=forms.StaticSelect2)
+
+    def __init__(self, *args, **kwargs):
+        """Conditionally hide the git_repository_branch field based on Nautobot version."""
+        super().__init__(*args, **kwargs)
+        if version.parse(settings.VERSION) < version.parse("2.4.2"):
+            self.fields["git_repository_branch"].widget = django_forms.HiddenInput