fix: handle ill-formed profiles created by older rockcraft

Older versions of rockcraft may have created a rockcraft lxd project
containing a broken default profile. If this is the case, tell the
user to delete the project and start over.

Signed-off-by: Claudio Matsuoka <claudio.matsuoka@canonical.com>

craft_providers/lxd/installer.py

@@ -79,7 +79,7 @@ def install(sudo: bool = True) -> str:
     return lxd.version()
 
 
-def is_initialized(*, remote: str, lxc: LXC) -> bool:
+def is_initialized(*, remote: str, project: str, lxc: LXC) -> bool:
     """Verify that LXD has been initialized and configuration looks valid.
 
     If LXD has been installed but the user has not initialized it (lxd init),
@@ -153,7 +153,11 @@ def is_user_permitted() -> bool:
 
 
 def ensure_lxd_is_ready(
-    *, remote: str = "local", lxc: LXC = LXC(), lxd: LXD = LXD()
+    *,
+    remote: str = "local",
+    project: str = "default",
+    lxc: LXC = LXC(),
+    lxd: LXD = LXD(),
 ) -> None:
     """Ensure LXD is ready for use.
 
@@ -185,7 +189,7 @@ def ensure_lxd_is_ready(
             ),
         )
 
-    if not is_initialized(lxc=lxc, remote=remote):
+    if not is_initialized(lxc=lxc, project=project, remote=remote):
         raise errors.LXDError(
             brief="LXD has not been properly initialized.",
             details=(

craft_providers/lxd/lxd_provider.py

@@ -26,7 +26,7 @@
 from craft_providers.base import Base
 from craft_providers.errors import BaseConfigurationError
 
-from .errors import LXDError, LXDUnstableImageError
+from .errors import LXD_INSTALL_HELP, LXDError, LXDUnstableImageError
 from .installer import ensure_lxd_is_ready, install, is_installed
 from .launcher import launch
 from .lxc import LXC
@@ -126,6 +126,26 @@ def launched_environment(
 
         :raises LXDError: if instance cannot be configured and launched.
         """
+        projects = self.lxc.project_list(remote=self.lxd_remote)
+        if self.lxd_project in projects:
+            devices = self.lxc.profile_show(
+                project=self.lxd_project, profile="default", remote=self.lxd_remote
+            ).get("devices")
+            if not devices:
+                # Project "rockcraft" exists but the default profile is ill-formed,
+                # delete the project and start over.
+                raise LXDError(
+                    brief="LXD project has an ill-formed default profile.",
+                    details=(
+                        f"The default profile in the LXD project '{self.lxd_project}' "
+                        "has an empty devices section."
+                    ),
+                    resolution=(
+                        "Delete the 'rockcraft' LXD project, it will be recreated in the "
+                        "next execution.\n" + LXD_INSTALL_HELP
+                    ),
+                )
+
         if build_base:
             logger.warning(
                 "Deprecated: Parameter 'build_base' is deprecated and should "