ci: POC arm64 runner

- Fix issue #314, missing testing model on crashdump
- Add arm64 functional test
- Add arm64 charm build

.github/workflows/check.yaml

@@ -82,8 +82,8 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        runs-on: [[ubuntu-22.04]]
-        test-command: ['tox -e func -- --series focal', 'tox -e func -- --series jammy']
+        runs-on: [[ubuntu-22.04], [Ubuntu_ARM64_4C_16G_01]]
+        test-command: ['tox -e func -- --series focal --keep-models', 'tox -e func -- --series jammy --keep-models']
         juju-channel: ["3.4/stable"]
     steps:
 

charmcraft.yaml

@@ -14,20 +14,23 @@ bases:
   - build-on:
     - name: ubuntu
       channel: "22.04"
-      architectures: ["amd64"]
+      architectures: ["amd64", "arm64"]
     run-on:
       - name: ubuntu
         channel: "24.04"
         architectures:
           - amd64
+          - arm64
       - name: ubuntu
         channel: "22.04"
         architectures:
           - amd64
+          - arm64
       - name: ubuntu
         channel: "20.04"
         architectures:
           - amd64
+          - arm64
 
 actions:
   redetect-hardware:

tests/functional/conftest.py

@@ -1,4 +1,5 @@
 import logging
+import platform
 
 import pytest
 from utils import RESOURCES_DIR, Resource
@@ -41,6 +42,14 @@ def series(request):
     return request.config.getoption("--series")
 
 
+@pytest.fixture(scope="module")
+def architecture():
+    machine = platform.machine()
+    if machine == "aarch64":
+        return "arm64"
+    return "amd64"
+
+
 @pytest.fixture(scope="module")
 def provided_collectors(request):
     return set(request.config.getoption("collectors"))

tests/functional/test_charm.py

@@ -56,7 +56,7 @@ class AppStatus(str, Enum):
 @pytest.mark.abort_on_fail
 @pytest.mark.skip_if_deployed
 async def test_build_and_deploy(  # noqa: C901, function is too complex
-    ops_test: OpsTest, series, provided_collectors, required_resources
+    ops_test: OpsTest, series, architecture, provided_collectors, required_resources
 ):
     """Build the charm-under-test and deploy it together with related charms.
 
@@ -67,6 +67,11 @@ async def test_build_and_deploy(  # noqa: C901, function is too complex
     charm = await ops_test.build_charm(".")
     assert charm, "Charm was not built successfully."
 
+    # This is required for subordinate appliation to choose right revison
+    # on different architecture.
+    # See issue: https://bugs.launchpad.net/juju/+bug/2067749
+    await ops_test.model.set_constraints({"arch": architecture})
+
     bundle_template_path = get_this_script_dir() / "bundle.yaml.j2"
 
     logger.info("Rendering bundle %s", bundle_template_path)