Merge pull request #1050 from octodns/yaml-includes

Add support for !include YAML directive

CHANGELOG.md

@@ -15,6 +15,10 @@
   common records across all zones using the provider. It can be used stand-alone
   or in combination with zone files and/or split configs to aid in DRYing up DNS
   configs.
+* YamlProvider now supports an `!include` directive which enables shared
+  snippets of config to be reused across many records, e.g. common dynamic rules
+  across a set of services with service-specific pool values or a unified SFP
+  value included in TXT records at the root of all zones.
 
 #### Stuff
 

octodns/yaml.py

@@ -2,6 +2,8 @@
 #
 #
 
+from os.path import dirname, join
+
 from natsort import natsort_keygen
 from yaml import SafeDumper, SafeLoader, dump, load
 from yaml.constructor import ConstructorError
@@ -23,7 +25,17 @@ class ContextLoader(SafeLoader):
     def _construct(self, node):
         return self._pairs(node)[0]
 
+    def include(self, node):
+        mark = self.get_mark()
+        directory = dirname(mark.name)
+
+        filename = join(directory, self.construct_scalar(node))
+
+        with open(filename, 'r') as fh:
+            return safe_load(fh, self.__class__)
+
 
+ContextLoader.add_constructor('!include', ContextLoader.include)
 ContextLoader.add_constructor(
     ContextLoader.DEFAULT_MAPPING_TAG, ContextLoader._construct
 )

tests/config/include/array.yaml

@@ -0,0 +1,5 @@
+---
+- 14
+- 15
+- 16
+- 72

tests/config/include/dict.yaml

@@ -0,0 +1,3 @@
+---
+k: v
+z: 42

tests/config/include/empty.yaml

@@ -0,0 +1 @@
+---

tests/config/include/include-doesnt-exist.yaml

@@ -0,0 +1,2 @@
+---
+key: !include does-not-exist.yaml

tests/config/include/main.yaml

@@ -0,0 +1,8 @@
+---
+included-array: !include array.yaml
+included-dict: !include dict.yaml
+included-empty: !include empty.yaml
+included-nested: !include nested.yaml
+included-subdir: !include subdir/value.yaml
+key: value
+name: main

tests/config/include/nested.yaml

@@ -0,0 +1,2 @@
+---
+!include subdir/value.yaml

tests/config/include/subdir/value.yaml

@@ -0,0 +1,2 @@
+---
+Hello World!

tests/test_octodns_yaml.py

@@ -62,3 +62,27 @@ class TestYaml(TestCase):
         buf = StringIO()
         safe_dump({'45a03129': 42, '45a0392a': 43}, buf)
         self.assertEqual("---\n45a0392a: 43\n45a03129: 42\n", buf.getvalue())
+
+    def test_include(self):
+        with open('tests/config/include/main.yaml') as fh:
+            data = safe_load(fh)
+        self.assertEqual(
+            {
+                'included-array': [14, 15, 16, 72],
+                'included-dict': {'k': 'v', 'z': 42},
+                'included-empty': None,
+                'included-nested': 'Hello World!',
+                'included-subdir': 'Hello World!',
+                'key': 'value',
+                'name': 'main',
+            },
+            data,
+        )
+
+        with open('tests/config/include/include-doesnt-exist.yaml') as fh:
+            with self.assertRaises(FileNotFoundError) as ctx:
+                data = safe_load(fh)
+            self.assertEqual(
+                "[Errno 2] No such file or directory: 'tests/config/include/does-not-exist.yaml'",
+                str(ctx.exception),
+            )