blueprints: Add support for generating flat and unique sequences in blueprint enumeration tags

authentik/blueprints/tests/fixtures/tags.yaml

@@ -121,6 +121,16 @@ entries:
                   SEQ,
                   !Format ["prefixed-items-%%s-%%s", !Index 0, !Value 0]
               ]
+              enumerate_nested_sequence_to_flat_sequence: !Enumerate [
+                  [!Context sequence, !Context sequence, scalar_value, [[deeply_nested]]],
+                  FLAT_SEQ,
+                  !Value 0
+              ]
+              enumerate_sequence_to_uniq_sequence: !Enumerate [
+                  ["foo", "bar", "foo"],
+                  UNIQ_SEQ,
+                  !Value 0
+              ]
               enumerate_sequence_to_mapping: !Enumerate [
                   !Context sequence,
                   MAP,

authentik/blueprints/tests/test_v1.py

@@ -186,6 +186,18 @@ def test_import_yaml_tags(self):
                     "prefixed-items-0-foo",
                     "prefixed-items-1-bar",
                 ],
+                "enumerate_nested_sequence_to_flat_sequence": [
+                    "foo",
+                    "bar",
+                    "foo",
+                    "bar",
+                    "scalar_value",
+                    "deeply_nested",
+                ],
+                "enumerate_sequence_to_uniq_sequence": [
+                    "foo",
+                    "bar",
+                ],
                 "enumerate_sequence_to_mapping": {"index: 0": "foo", "index: 1": "bar"},
                 "nested_complex_enumeration": {
                     "0": {

authentik/blueprints/v1/common.py

@@ -15,6 +15,7 @@
 from deepmerge import always_merger
 from django.apps import apps
 from django.db.models import Model, Q
+from more_itertools import collapse, unique_everseen
 from rest_framework.exceptions import ValidationError
 from rest_framework.fields import Field
 from rest_framework.serializers import Serializer
@@ -504,13 +505,16 @@ class Enumerate(YAMLTag, YAMLTagContext):
 
     iterable: YAMLTag | Iterable
     item_body: Any
-    output_body: Literal["SEQ", "MAP"]
+    output_body: Literal["SEQ", "FLAT_SEQ", "UNIQ_SEQ", "MAP"]
 
     _OUTPUT_BODIES = {
-        "SEQ": (list, lambda a, b: [*a, b]),
+        "SEQ": (list, lambda a, b: [*a, b], None),
+        "FLAT_SEQ": (list, lambda a, b: [*a, b], lambda x: list(collapse(x))),
+        "UNIQ_SEQ": (list, lambda a, b: [*a, b], lambda x: list(unique_everseen(x, key=tuple))),
         "MAP": (
             dict,
             lambda a, b: always_merger.merge(a, {b[0]: b[1]} if isinstance(b, tuple | list) else b),
+            None,
         ),
     }
 
@@ -550,7 +554,7 @@ def resolve(self, entry: BlueprintEntry, blueprint: Blueprint) -> Any:
             iterable = tuple(enumerate(iterable))
 
         try:
-            output_class, add_fn = self._OUTPUT_BODIES[self.output_body.upper()]
+            output_class, add_fn, post_process_fn = self._OUTPUT_BODIES[self.output_body.upper()]
         except KeyError as exc:
             raise EntryInvalidError.from_entry(exc, entry) from exc
 
@@ -570,7 +574,7 @@ def resolve(self, entry: BlueprintEntry, blueprint: Blueprint) -> Any:
         finally:
             self.__current_context = tuple()
 
-        return result
+        return post_process_fn(result) if post_process_fn else result
 
 
 class EnumeratedItem(YAMLTag):

pyproject.toml

@@ -44,6 +44,7 @@ dependencies = [
   "kubernetes==35.0.0",
   "ldap3==2.9.1",
   "lxml==6.0.2",
+  "more-itertools>=10.8.0",
   "msgraph-sdk==1.55.0",
   "opencontainers==0.0.15",
   "packaging==26.0",

website/docs/customize/blueprints/v1/tags.mdx

@@ -208,9 +208,13 @@ This tag takes 3 arguments:
 ```
 
 - **iterable**: Any Python iterable or custom tag that resolves to such iterable
-- **output_object_type**: `SEQ` or `MAP`. Controls whether the returned YAML will be a mapping or a sequence.
+- **output_object_type**: `SEQ`, `FLAT_SEQ`, `UNIQ_SEQ` or `MAP`. Controls whether the returned YAML will be a mapping or a sequence. With `FLAT_SEQ` the resulting list will also be flattened, while with `UNIQ_SEQ` duplicated entries will be removed
 - **single_item_yaml**: The YAML to use to create a single entry in the output object
 
+:::info
+`FLAT_SEQ` and `UNIQ_SEQ` require authentik 2026.05+
+:::
+
 2. `!Index` tag:
 
 :::info