fix for omitting identity section when passing user-data

examples/autoinstall-user-data.yaml

@@ -0,0 +1,19 @@
+version: 1
+early-commands:
+  - echo a
+  - sleep 1
+  - echo a
+debconf-selections: eek
+packages:
+  - package1
+  - package2
+late-commands:
+  - echo a
+  - sleep 1
+  - echo a
+keyboard:
+  layout: gb
+user-data:
+  users:
+    - username: ubuntu
+      password: '$6$wdAcoXrU039hKYPd$508Qvbe7ObUnxoj15DRCkzC3qO7edjH0VV7BPNRDYK4QR8ofJaEEF2heacn0QgD.f8pO8SNp83XNdWG6tocBM1'

scripts/runtests.sh

@@ -32,3 +32,8 @@ grep 'finish: subiquity/InstallProgress/postinstall/install_package1: SUCCESS: i
      .subiquity/subiquity-debug.log
 grep 'finish: subiquity/InstallProgress/postinstall/install_package2: SUCCESS: installing package2' \
      .subiquity/subiquity-debug.log
+
+timeout --foreground 60 sh -c "LANG=C.UTF-8 python3 -m subiquity.cmd.tui --autoinstall examples/autoinstall-user-data.yaml \
+                               --dry-run --machine-config examples/simple.json \
+                               --kernel-cmdline 'autoinstall console=\"${TTY#/dev/}\"'"
+python3 scripts/validate-yaml.py .subiquity/subiquity-curtin-install.conf 

subiquity/controllers/identity.py

@@ -73,6 +73,8 @@ class IdentityController(SubiquityController):
         self.app.next_screen()
 
     def make_autoinstall(self):
+        if self.model.user is None:
+            return {}
         r = attr.asdict(self.model.user)
         r['hostname'] = self.model.hostname
         return r

subiquity/models/subiquity.py

@@ -202,14 +202,18 @@ class SubiquityModel:
         # (mwhudson does not entirely know what the above means!)
         userdata = '#cloud-config\n' + yaml.dump(self._cloud_init_config())
         metadata = yaml.dump({'instance-id': str(uuid.uuid4())})
-        hostname = self.identity.hostname.strip()
-        return [
+        files = [
             ('var/lib/cloud/seed/nocloud-net/meta-data', metadata, 0o644),
             ('var/lib/cloud/seed/nocloud-net/user-data', userdata, 0o600),
             ('etc/cloud/ds-identify.cfg', 'policy: enabled\n', 0o644),
+            ]
+        if self.identity.hostname is not None:
+            hostname = self.identity.hostname.strip()
+            files.extend([
                 ('etc/hostname', hostname + "\n", 0o644),
                 ('etc/hosts', HOSTS_CONTENT.format(hostname=hostname), 0o644),
-            ]
+                ])
+        return files
 
     def configure_cloud_init(self):
         for path, content, mode in self._cloud_init_files():