[DPE-5588] Check against invalid arch (#563)

src/charm.py

@@ -4,6 +4,12 @@
 
 """Charmed Machine Operator for MySQL."""
 
+from charms.mysql.v0.architecture import WrongArchitectureWarningCharm, is_wrong_architecture
+from ops.main import main
+
+if is_wrong_architecture() and __name__ == "__main__":
+    main(WrongArchitectureWarningCharm)
+
 import logging
 import random
 import socket
@@ -55,7 +61,6 @@
     Unit,
     WaitingStatus,
 )
-from ops.main import main
 from tenacity import (
     RetryError,
     Retrying,

tests/integration/helpers.py

@@ -8,7 +8,8 @@
 import string
 import subprocess
 import tempfile
-from typing import Dict, List, Optional, Set
+from pathlib import Path
+from typing import Dict, List, Optional, Set, Union
 
 import juju.unit
 import yaml
@@ -979,3 +980,17 @@ def get_unit_by_index(app_name: str, units: list, index: int):
     for unit in units:
         if unit.name == f"{app_name}/{index}":
             return unit
+
+
+async def get_charm(charm_path: Union[str, Path], architecture: str, bases_index: int) -> Path:
+    """Fetches packed charm from CI runner without checking for architecture."""
+    charm_path = Path(charm_path)
+    charmcraft_yaml = yaml.safe_load((charm_path / "charmcraft.yaml").read_text())
+    assert charmcraft_yaml["type"] == "charm"
+
+    base = charmcraft_yaml["bases"][bases_index]
+    build_on = base.get("build-on", [base])[0]
+    version = build_on["channel"]
+    packed_charms = list(charm_path.glob(f"*{version}-{architecture}.charm"))
+
+    return packed_charms[0].resolve(strict=True)

tests/integration/test_architecture.py

@@ -0,0 +1,53 @@
+#!/usr/bin/env python3
+# Copyright 2024 Canonical Ltd.
+# See LICENSE file for licensing details.
+
+import pytest
+from pytest_operator.plugin import OpsTest
+
+from . import markers
+from .helpers import get_charm
+
+MYSQL_APP_NAME = "mysql"
+
+
+@pytest.mark.group(1)
+@markers.amd64_only
+async def test_arm_charm_on_amd_host(ops_test: OpsTest) -> None:
+    """Tries deploying an arm64 charm on amd64 host."""
+    charm = await get_charm(".", "arm64", 1)
+
+    await ops_test.model.deploy(
+        charm,
+        application_name=MYSQL_APP_NAME,
+        num_units=1,
+        config={"profile": "testing"},
+        base="[email protected]",
+    )
+
+    await ops_test.model.wait_for_idle(
+        apps=[MYSQL_APP_NAME],
+        status="error",
+        raise_on_error=False,
+    )
+
+
+@pytest.mark.group(1)
+@markers.arm64_only
+async def test_amd_charm_on_arm_host(ops_test: OpsTest) -> None:
+    """Tries deploying an amd64 charm on arm64 host."""
+    charm = await get_charm(".", "amd64", 0)
+
+    await ops_test.model.deploy(
+        charm,
+        application_name=MYSQL_APP_NAME,
+        num_units=1,
+        config={"profile": "testing"},
+        base="[email protected]",
+    )
+
+    await ops_test.model.wait_for_idle(
+        apps=[MYSQL_APP_NAME],
+        status="error",
+        raise_on_error=False,
+    )