Introduce two env vars for UEP customization

- `GC_USER_PYTHON_VERSION`
- `GC_USER_SDK_VERSION`

If the information is available in the `user_runtime` data structure, also
export these two environment variables.  These two bits of information have
proven critical to helping administrators customize UEP installs.  In
particular, the latter (SDK) variable is necessary to get Parsl versions to
match up on the interchange and workers.  (An unfortunate detail that we must
accommodate until Parsl implements a less-strict communication policy.)

Setting these environment variables means that administrators don't have to go
through an awkward set of steps to read stdin, parse the input, and rewrite the
stdin just to get this information from the template.

[sc-41149]

Author: khk-globus

changelog.d/20260310_134848_kevin_add_gc_env_vars_to_aid_uep_setup.rst

@@ -0,0 +1,6 @@
+New Functionality
+^^^^^^^^^^^^^^^^^
+
+- To aid potential UEP instance customization, export
+  ``GC_USER_PYTHON_VERSION`` and ``GC_USER_SDK_VERSION`` (if available from the
+  :ref:`user_runtime <reserved-template-variables>` structure)

compute_endpoint/globus_compute_endpoint/endpoint/endpoint_manager.py

@@ -1175,6 +1175,12 @@ def cmd_start_endpoint(
                 user_opts,
                 user_runtime,
             )
+
+            if py_version := user_runtime.get("python", {}).get("version"):
+                env.setdefault("GC_USER_PYTHON_VERSION", py_version)
+            if gce_version := user_runtime.get("globus_compute_sdk_version"):
+                env.setdefault("GC_USER_SDK_VERSION", gce_version)
+
             exit_code += 1
             _conf = yaml.safe_load(user_config)
 

compute_endpoint/tests/unit/test_endpointmanager_unit.py

@@ -338,6 +338,12 @@ def command_payload(ident):
             "name": "some_ep_name",
             "user_opts": {"heartbeat": 10},
             "amqp_creds": {},
+            "user_runtime": {
+                "python": {
+                    "version": "3.4.2",
+                },
+                "globus_compute_sdk_version": "2.90.2",
+            },
         },
     }
 
@@ -578,7 +584,7 @@ def test_records_user_ep_as_running(successful_exec_from_mocked_root):
 
 
 def test_caches_start_cmd_args_if_ep_already_running(
-    successful_exec_from_mocked_root, mocker
+    mocker, successful_exec_from_mocked_root, command_payload
 ):
     *_, em = successful_exec_from_mocked_root
     child_pid = random.randrange(1, 32768 + 1)
@@ -592,10 +598,9 @@ def test_caches_start_cmd_args_if_ep_already_running(
     cached_args = em._cached_cmd_start_args.pop(child_pid)
     assert cached_args is not None
     mpi, args, kwargs = cached_args
-    exp_kw = {"name": "some_ep_name", "user_opts": {"heartbeat": 10}, "amqp_creds": {}}
     assert mpi.local_user_record == _mock_localuser_rec
     assert args == []
-    assert kwargs == exp_kw
+    assert kwargs == command_payload["kwargs"]
 
 
 def test_writes_endpoint_uuid(epmanager_as_root):
@@ -1688,6 +1693,22 @@ def test_environment_default_path_set_if_not_specified(
     assert "PATH" in env, "Expected PATH is always set"
 
 
+def test_environment_includes_user_versions(
+    command_payload, successful_exec_from_mocked_root
+):
+    mock_os, conf_dir, *_, em = successful_exec_from_mocked_root
+
+    urun = command_payload["kwargs"]["user_runtime"]
+    with pytest.raises(SystemExit) as pyexc:
+        em._event_loop()
+
+    assert pyexc.value.code == _GOOD_EC, "Q&D: verify we exec'ed, based on '+= 1'"
+    _, k = mock_os.execvpe.call_args
+    env = k["env"]
+    assert urun["python"]["version"] == env["GC_USER_PYTHON_VERSION"]
+    assert urun["globus_compute_sdk_version"] == env["GC_USER_SDK_VERSION"]
+
+
 def test_warns_if_executable_not_found(
     mock_log, successful_exec_from_mocked_root, randomstring
 ):

docs/endpoints/endpoints.rst

@@ -715,6 +715,18 @@ and writing a custom ``globus-compute-endpoint`` wrapper:
 
 (The use of ``exec`` is not critical, but keeps the process tree tidy.)
 
+The manager endpoint process exports the following two environment variables that
+shim‑authors may use to fine‑tune customizations:
+
+- ``GC_USER_PYTHON_VERSION`` - A dotted-decimal Python version (e.g., ``3.13.7``) that
+  specifies which version of Python was used to submit tasks to this endpoint
+
+- ``GC_USER_SDK_VERSION`` - A dotted-decimal ``globus-compute-sdk`` version (e.g.,
+  ``4.8.0``) that specifies what version of the `Globus Compute SDK`_ the submission
+  used
+
+.. _Globus Compute SDK: https://pypi.org/project/globus-compute-sdk/
+
 
 Debugging
 =========