Fix mypy: narrow scenario type via get_library_init_image() helper

context.scenario is typed as the base Scenario; access the init image through a
helper that asserts isinstance(K8sScenario) (mirrors get_cluster_info's narrowing).

Author: knusbaum

tests/k8s_lib_injection/test_k8s_lib_injection.py

@@ -1,5 +1,10 @@
 from utils import scenarios, features, context, bug, logger
-from tests.k8s_lib_injection.utils import get_dev_agent_traces, get_cluster_info, run_https_probe_pod
+from tests.k8s_lib_injection.utils import (
+    get_dev_agent_traces,
+    get_cluster_info,
+    get_library_init_image,
+    run_https_probe_pod,
+)
 from utils.onboarding.weblog_interface import make_get_request, warmup_weblog
 from utils.onboarding.backend_interface import wait_backend_trace_id
 from utils.onboarding.wait_for_tcp_port import wait_for_port
@@ -27,7 +32,7 @@ def test_k8s_init_container_https_egress(self):
         pod from the init image doing `curl -fsS https://...` (verification on) and asserts it
         succeeds; a missing or broken cert store makes curl exit non-zero.
         """
-        image = context.scenario.test_weblog.library_init_image
+        image = get_library_init_image()
         phase, logs = run_https_probe_pod(get_cluster_info(), image, "https://app.datadoghq.com")
         if phase != "Succeeded":
             logger.error(f"[HTTPS probe] init image {image} failed HTTPS egress; pod logs:\n{logs}")

tests/k8s_lib_injection/utils.py

@@ -5,7 +5,7 @@
 
 from utils import logger, context
 from utils.k8s_lib_injection.k8s_cluster_provider import K8sClusterInfo
-from utils._context._scenarios.k8s_lib_injection import K8sScenarioWithClusterProvider
+from utils._context._scenarios.k8s_lib_injection import K8sScenario, K8sScenarioWithClusterProvider
 
 
 def get_dev_agent_traces(k8s_cluster_info: K8sClusterInfo, retry: int = 10) -> list:
@@ -28,6 +28,13 @@ def get_cluster_info() -> K8sClusterInfo:
     return context.scenario.k8s_cluster_provider.get_cluster_info()
 
 
+def get_library_init_image() -> str:
+    """Return the init image under test (the image the scenario deploys as the init container)."""
+    assert isinstance(context.scenario, K8sScenario)
+
+    return context.scenario.test_weblog.library_init_image
+
+
 def run_https_probe_pod(
     k8s_cluster_info: K8sClusterInfo, image: str, url: str, *, namespace: str = "default", timeout: int = 120
 ) -> tuple[str | None, str]: