Add s390x integration tests

Author: carlcsaposs-canonical

.github/workflows/integration_test.yaml

@@ -42,7 +42,9 @@ jobs:
               _, runner, task, variant = job.split(":")
               # Example: "test_charm.py"
               task = task.removeprefix("tests/spread/")
-              if runner.endswith("-arm"):
+              if "s390x" in runner:
+                  architecture = "s390x"
+              elif runner.endswith("-arm"):
                   architecture = "arm64"
               else:
                   architecture = "amd64"

spread.yaml

@@ -97,6 +97,10 @@ backends:
           username: runner
           variants:
             - -juju29_ubuntu22
+      - self-hosted-linux-s390x-noble-edge:
+          username: runner
+          variants:
+            - -juju29_ubuntu22
 
 suites:
   tests/spread/:

tests/integration/markers.py

@@ -11,3 +11,6 @@
 arm64_only = pytest.mark.skipif(
     architecture.architecture != "arm64", reason="Requires arm64 architecture"
 )
+s390x_only = pytest.mark.skipif(
+    architecture.architecture != "s390x", reason="Requires s390x architecture"
+)

tests/integration/test_architecture.py

@@ -81,4 +81,34 @@ async def test_amd_charm_on_arm_host(ops_test: OpsTest, charm, series) -> None:
     )
 
 
-# TODO: add s390x test
+@markers.s390x_only
+async def test_amd_charm_on_s390x_host(ops_test: OpsTest, charm, series) -> None:
+    """Tries deploying an amd64 charm on s390x host."""
+    charm = charm.replace("s390x", "amd64")
+
+    await asyncio.gather(
+        ops_test.model.deploy(
+            charm,
+            application_name=MYSQL_ROUTER_APP_NAME,
+            num_units=0,
+            series=series,
+        ),
+        ops_test.model.deploy(
+            MYSQL_TEST_APP_NAME,
+            application_name=MYSQL_TEST_APP_NAME,
+            num_units=1,
+            channel="latest/edge",
+            series=series,
+        ),
+    )
+
+    await ops_test.model.relate(
+        f"{MYSQL_ROUTER_APP_NAME}:database",
+        f"{MYSQL_TEST_APP_NAME}:database",
+    )
+
+    await ops_test.model.wait_for_idle(
+        apps=[MYSQL_ROUTER_APP_NAME],
+        status="error",
+        raise_on_error=False,
+    )