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"
@@ -86,15 +88,20 @@ jobs:
     runs-on: ${{ matrix.job.runner }}
     timeout-minutes: 217  # Sum of steps `timeout-minutes` + 5
     steps:
-      - name: Free up disk space
+      - name: (GitHub hosted) Free up disk space
         timeout-minutes: 1
+        if: ${{ !contains(matrix.job.runner, 'self-hosted') }}
         run: |
           printf '\nDisk usage before cleanup\n'
           df --human-readable
           # Based on https://github.com/actions/runner-images/issues/2840#issuecomment-790492173
           rm -r /opt/hostedtoolcache/
           printf '\nDisk usage after cleanup\n'
           df --human-readable
+      - name: (IS hosted) Disk usage
+        timeout-minutes: 1
+        if: ${{ contains(matrix.job.runner, 'self-hosted') }}
+        run: df --human-readable
       - name: Checkout
         timeout-minutes: 3
         uses: actions/checkout@v4

spread.yaml

@@ -93,6 +93,18 @@ backends:
           username: runner
           variants:
             - -juju29
+      - self-hosted-linux-s390x-noble-edge:
+          username: ubuntu
+          environment:
+            # Several python packages (e.g. cryptography, bcrypt) do not have s390x builds on PyPI,
+            # so they must be built from source. pkg-config & rust toolchain needed
+            # (These packages are being built when installing poetry or integration test Python
+            # dependencies)
+            CONCIERGE_EXTRA_DEBS: pipx,pkg-config,rustup
+            # s390x only available on edge
+            CONCIERGE_MICROK8S_CHANNEL: 1.32-strict/edge
+          variants:
+            - -juju29
 
 suites:
   tests/spread/:
@@ -109,10 +121,18 @@ prepare: |
   snap refresh --hold
   chown -R root:root "$SPREAD_PATH"
   cd "$SPREAD_PATH"
-  snap install --classic concierge
+  # Install via snap after https://github.com/canonical/concierge/pull/81 released
+  go install github.com/canonical/concierge@latest
+
+  # Install charmcraft & pipx on lxd-vm backend and install pipx on IS-hosted runners
+  ~/go/bin/concierge prepare --trace
 
-  # Install charmcraft & pipx (on lxd-vm backend)
-  concierge prepare --trace
+  if [[ $SPREAD_SYSTEM == *"s390x"* ]]
+  then
+    rustup set profile minimal
+    # TODO add renovate comment for rust version
+    rustup default 1.88.0
+  fi
 
   pipx install tox poetry
 prepare-each: |
@@ -124,7 +144,7 @@ prepare-each: |
     poetry add --lock --group integration juju@^2
   fi
   # `concierge prepare` needs to be run for each spread job in case Juju version changed
-  concierge prepare --trace
+  ~/go/bin/concierge prepare --trace
 
   # Unable to set constraint on all models because of Juju bug:
   # https://bugs.launchpad.net/juju/+bug/2065050

tests/integration/markers.py

@@ -15,3 +15,6 @@
 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

@@ -61,4 +61,25 @@ async def test_amd_charm_on_arm_host(ops_test: OpsTest) -> None:
     )
 
 
-# TODO: add s390x test
+@markers.arm64_only
+async def test_amd_charm_on_s390x_host(ops_test: OpsTest) -> None:
+    """Tries deploying an amd64 charm on s390x host."""
+    charm = "./[email protected]"
+
+    resources = {
+        "mysql-router-image": METADATA["resources"]["mysql-router-image"]["upstream-source"]
+    }
+
+    await ops_test.model.deploy(
+        charm,
+        application_name=MYSQL_ROUTER_APP_NAME,
+        num_units=1,
+        resources=resources,
+        base="[email protected]",
+    )
+
+    await ops_test.model.wait_for_idle(
+        apps=[MYSQL_ROUTER_APP_NAME],
+        status="error",
+        raise_on_error=False,
+    )