Add instance_life_cycle attribute (#535)

Fixes #440.

CHANGELOG.rst

@@ -2,6 +2,10 @@
 Changelog
 =========
 
+* Add ``instance_life_cycle`` attribute.
+
+  Thanks to Zeev Rotshtein for the feature request in `Issue #440 <https://github.com/adamchainz/ec2-metadata/issues/440>`__.
+
 * Drop Python 3.8 support.
 
 * Support Python 3.13.

README.rst

@@ -244,6 +244,11 @@ The dict has this type, based on that document:
         region: str
         version: str
 
+``instance_life_cycle: str``
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The purchasing option of this instance, for example ``'on-demand'``.
+
 ``instance_profile_arn: str | None``
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

src/ec2_metadata/__init__.py

@@ -178,6 +178,10 @@ def instance_identity_document(self) -> InstanceIdentityDocumentDict:
         ).json()
         return result
 
+    @cached_property
+    def instance_life_cycle(self) -> str:
+        return self._get_url(f"{self.metadata_url}instance-life-cycle").text
+
     @property
     def instance_profile_arn(self) -> str | None:
         iam_info = self.iam_info

tests/test_ec2_metadata.py

@@ -268,6 +268,13 @@ def test_instance_identity(em_requests_mock):
     assert ec2_metadata.instance_identity_document == identity_doc
 
 
+def test_instance_life_cycle(em_requests_mock):
+    em_requests_mock.get(
+        "http://169.254.169.254/latest/meta-data/instance-life-cycle", text="on-demand"
+    )
+    assert ec2_metadata.instance_life_cycle == "on-demand"
+
+
 def test_instance_profile_arn(em_requests_mock):
     em_requests_mock.get(
         "http://169.254.169.254/latest/meta-data/iam/info",