testing: Add NoCloud setup for NoCloud test (SC-983)

[TheRealFalcon]

Proposed Commit Message

testing: Add NoCloud setup for NoCloud test

tests.integration_tests.bugs.test_gh570.test_nocloud_seedfrom_vendordata
is currently failing on Jammy because Jammy no longer uses NoCloud
and instead uses the LXD DataSource. This commit adds a NoCloud
setup to the failing test so we can force the NoCloud datasource.

Also, I moved the test into a NoCloud specific file, so any other
tests that need to be NoCloud specific can use the setup.

Additional Context

Review commits in order to see the actual changes

Failing test:
https://jenkins.canonical.com/server-team/view/cloud-init/job/cloud-init-integration-jammy-lxd_container/20/testReport/tests.integration_tests.bugs/test_gh570/test_nocloud_seedfrom_vendordata/

[TheRealFalcon]

I'll fix the mypy issue, but should otherwise be reviewable

[blackboxsw]

Thanks for this cleanup.

[blackboxsw]

TIL about --create-dirs. Thanks.

[blackboxsw]

I think we probably can avoid coupling this implementation to specific series. Given that the underlying cause of the symptom is that LXD on jammy and later will no longer ship metadata templates for nocloud-net files, we can check that metadata and honor any image that doesn't contain these templates.

Here's an alternative suggestion which works on focal and jammy lxd_containers. I don't know if you find lxd config cmdline manipulation more busy than tempfile creation and lxc file push .

diff --git a/tests/integration_tests/datasources/test_nocloud.py b/tests/integration_tests/datasources/test_nocloud.py
index b496d5887..d9410410b 100644
--- a/tests/integration_tests/datasources/test_nocloud.py
+++ b/tests/integration_tests/datasources/test_nocloud.py
@@ -1,12 +1,8 @@
 """NoCloud datasource integration tests."""
-import tempfile
-from pathlib import Path
-
 import pytest
 from pycloudlib.lxd.instance import LXDInstance
 
 from cloudinit.subp import subp
-from tests.integration_tests.clouds import ImageSpecification
 from tests.integration_tests.instances import IntegrationInstance
 
 VENDOR_DATA = """\
@@ -16,32 +12,49 @@ runcmd:
 """
 
 
+LXD_METADATA_NOCLOUD_SEED = """\
+  /var/lib/cloud/seed/nocloud-net/meta-data:
+    when:
+    - create
+    - copy
+    create_only: false
+    template: emptycfg.tpl
+    properties:
+      default: |
+        #cloud-config
+        {}
+  /var/lib/cloud/seed/nocloud-net/user-data:
+    when:
+    - create
+    - copy
+    create_only: false
+    template: emptycfg.tpl
+    properties:
+      default: |
+        #cloud-config
+        {}
+"""
+
+
 def setup_nocloud(instance: LXDInstance):
     # On Jammy and above, LXD no longer uses NoCloud, so we need to set
     # it up manually
-    if ImageSpecification.from_os_image().release in [
-        "bionic",
-        "focal",
-        "impish",
-    ]:
+    lxd_image_metadata = subp(
+        ["lxc", "config", "metadata", "show", instance.name]
+    )
+    if "/var/lib/cloud/seed/nocloud-net" in lxd_image_metadata.stdout:
         return
-    with tempfile.TemporaryDirectory() as tmpdir_str:
-        tmpdir = Path(tmpdir_str)
-        userdata_file = tmpdir / "user-data"
-        metadata_file = tmpdir / "meta-data"
-        userdata_file.touch()
-        metadata_file.touch()
-        subp(
-            [
-                "lxc",
-                "file",
-                "push",
-                str(userdata_file),
-                str(metadata_file),
-                f"{instance.name}/var/lib/cloud/seed/nocloud-net/",
-                "--create-dirs",
-            ]
-        )
+    subp(
+        ["lxc", "config", "template", "create", instance.name, "emptycfg.tpl"],
+    )
+    subp(
+        ["lxc", "config", "template", "edit", instance.name, "emptycfg.tpl"],
+        data="#cloud-config\n{}\n",
+    )
+    subp(
+        ["lxc", "config", "metadata", "edit", instance.name],
+        data=f"{lxd_image_metadata.stdout}{LXD_METADATA_NOCLOUD_SEED}",
+    )
 
 
 # Only running on LXD container because we need NoCloud with custom setup
@@ -57,7 +70,6 @@ def test_nocloud_seedfrom_vendordata(client: IntegrationInstance):
     seed_dir = "/var/tmp/test_seed_dir"
     result = client.execute(
         "mkdir {seed_dir} && "
-        "mkdir -p /var/lib/cloud/seed/nocloud-net && "
         "touch {seed_dir}/user-data && "
         "touch {seed_dir}/meta-data && "
         "echo 'seedfrom: {seed_dir}/' > "

[TheRealFalcon]

Thanks, I like your solution better. Pushed.

[blackboxsw]

Well I have to agree with this PR now. Thanks @TheRealFalcon