tests: add integration test for validating Azure UUID case-insentive

tests/integration_tests/bugs/test_lp1835584.py

@@ -0,0 +1,70 @@
+""" Integration test for LP #1835584
+
+Kernels prior to 4.15 report dmi product_uuid as uppercase, Azure
+relies on system UUID as their "instance-id". Upgrades to kernels >= 4.15
+will represent the same product_uuid as lowercase. System UUID should be a
+case-insensitive comparison and avoid triggering "new instance" detection
+in cloud-init on Azure platform.
+
+The test will launch an Ubuntu image which has a 5.4 kernel. We allow cloud-init
+to detect the instance-id on the 5.4 kernel, set a 4.15 kernel as default and
+reboot the system. Expectation is that cloud-init retains same instance-id
+status and avoids triggering ssh host key regeneration across that reboot.
+
+Across the reboot, assert that we didn't re-run config_ssh by virtue of
+seeing only one semaphore creation log entry of type:
+
+ Writing to /var/lib/cloud/instances/<UUID>/sem/config_ssh -
+
+https://bugs.launchpad.net/cloud-init/+bug/1897099
+"""
+import re
+
+import pytest
+
+from tests.integration_tests.instances import IntegrationInstance
+
+
+USER_DATA = """\
+#cloud-config
+runcmd:
+  - 'wget https://kernel.ubuntu.com/~kernel-ppa/mainline/v4.14.120/linux-headers-4.14.120-0414120_4.14.120-0414120.201905161610_all.deb'
+  - 'wget https://kernel.ubuntu.com/~kernel-ppa/mainline/v4.14.120/linux-headers-4.14.120-0414120-generic_4.14.120-0414120.201905161610_amd64.deb'
+  - 'wget https://kernel.ubuntu.com/~kernel-ppa/mainline/v4.14.120/linux-image-unsigned-4.14.120-0414120-generic_4.14.120-0414120.201905161610_amd64.deb'
+  - 'wget https://kernel.ubuntu.com/~kernel-ppa/mainline/v4.14.120/linux-modules-4.14.120-0414120-generic_4.14.120-0414120.201905161610_amd64.deb'
+  - 'dpkg -i *.deb'
+"""
+
+
+def _check_iid_insensitive_across_kernel_upgrade(client):
+    uuid = client.read_from_file('/sys/class/dmi/id/product_uuid')
+    assert uuid.islower(), "UUID does not appear to be lowercase {}".format(
+        uuid
+    )
+    orig_kernel = client.execute('uname -r').strip()
+    assert "azure" in orig_kernel
+    orig_kernel = client.execute('uname -r').strip()
+    client.write_to_file(
+        "/etc/default/grub.d/90-generic.cfg",
+        "GRUB_FLAVOUR_ORDER=\"generic\"\n"
+    )
+    client.execute("update-grub")
+    client.restart()
+    new_kernel = client.execute('uname -r').strip()
+    assert orig_kernel != new_kernel
+    assert 'generic' in new_kernel
+    uuid = client.read_from_file('/sys/class/dmi/id/product_uuid')
+    assert uuid.isupper(), "UUID does not appear to be uppercase {}".format(
+        uuid
+    )
+    log = client.read_from_file('/var/log/cloud-init.log')
+    RE_CONFIG_SSH_SEMAPHORE = r'Writing.*sem/config_ssh '
+    ssh_runs = len(re.findall(RE_CONFIG_SSH_SEMAPHORE, log))
+    assert 1 == ssh_runs, "config_ssh ran too many times {}".format(ssh_runs)
+
+
+@pytest.mark.azure
+@pytest.mark.sru_next
+@pytest.mark.user_data(USER_DATA)
+def test_azure_kernel_upgrade_case_insensitive_uuid(client: IntegrationInstance):
+    _check_iid_insensitive_across_kernel_upgrade(client)

tox.ini

@@ -184,5 +184,6 @@ markers =
     instance_name: the name to be used for the test instance
     sru_2020_11: test is part of the 2020/11 SRU verification
     sru_2021_01: test is part of the 2021/01 SRU verification
+    sru_next: test is part of the next SRU verification
     ubuntu: this test should run on Ubuntu
     unstable: skip this test because it is flakey