From f2e3383b1d6e7b10bb242a8dfc2149a96e234b6b Mon Sep 17 00:00:00 2001
From: David Garcia <david.garcia@canonical.com>
Date: Thu, 2 Jun 2022 16:11:28 +0200
Subject: [PATCH] Fix bug 2060: Add logic to delete models gracefully

Change-Id: Icfda4b9d7ca67cd75621413ac09c6fc00857d1c2
Signed-off-by: David Garcia <david.garcia@canonical.com>
---
 n2vc/libjuju.py | 64 ++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 53 insertions(+), 11 deletions(-)

diff --git a/n2vc/libjuju.py b/n2vc/libjuju.py
index 9d9d08e..4ee0abf 100644
--- a/n2vc/libjuju.py
+++ b/n2vc/libjuju.py
@@ -926,6 +926,35 @@ class Libjuju:
             await self.disconnect_model(model)
             await self.disconnect_controller(controller)
 
+    async def resolve(self, model_name: str):
+
+        controller = await self.get_controller()
+        model = await self.get_model(controller, model_name)
+        all_units_active = False
+        try:
+            while not all_units_active:
+                all_units_active = True
+                for application_name, application in model.applications.items():
+                    if application.status == "error":
+                        for unit in application.units:
+                            if unit.workload_status == "error":
+                                self.log.debug(
+                                    "Model {}, Application {}, Unit {} in error state, resolving".format(
+                                        model_name, application_name, unit.entity_id
+                                    )
+                                )
+                                try:
+                                    await unit.resolved(retry=False)
+                                    all_units_active = False
+                                except Exception:
+                                    pass
+
+                if not all_units_active:
+                    await asyncio.sleep(5)
+        finally:
+            await self.disconnect_model(model)
+            await self.disconnect_controller(controller)
+
     async def scale_application(
         self,
         model_name: str,
@@ -1340,9 +1369,8 @@ class Libjuju:
             await self._destroy_pending_machines(model, only_manual=True)
             await self.disconnect_model(model)
 
-            await self._destroy_model(
-                model_name,
-                controller,
+            await asyncio.wait_for(
+                self._destroy_model(model_name, controller),
                 timeout=total_timeout,
             )
         except Exception as e:
@@ -1359,7 +1387,9 @@ class Libjuju:
             await self.disconnect_controller(controller)
 
     async def _destroy_model(
-        self, model_name: str, controller: Controller, timeout: float = 1800
+        self,
+        model_name: str,
+        controller: Controller,
     ):
         """
         Destroy model from controller
@@ -1370,21 +1400,33 @@ class Libjuju:
         """
         self.log.debug(f"Destroying model {model_name}")
 
-        async def _destroy_model_loop(model_name: str, controller: Controller):
-            while await self.model_exists(model_name, controller=controller):
+        async def _destroy_model_gracefully(model_name: str, controller: Controller):
+            self.log.info(f"Gracefully deleting model {model_name}")
+            resolved = False
+            while model_name in await controller.list_models():
+                if not resolved:
+                    await self.resolve(model_name)
+                    resolved = True
+                await controller.destroy_model(model_name, destroy_storage=True)
+
+                await asyncio.sleep(5)
+            self.log.info(f"Model {model_name} deleted gracefully")
+
+        async def _destroy_model_forcefully(model_name: str, controller: Controller):
+            self.log.info(f"Forcefully deleting model {model_name}")
+            while model_name in await controller.list_models():
                 await controller.destroy_model(
-                    model_name, destroy_storage=True, force=True, max_wait=0
+                    model_name, destroy_storage=True, force=True, max_wait=60
                 )
                 await asyncio.sleep(5)
+            self.log.info(f"Model {model_name} deleted forcefully")
 
         try:
             await asyncio.wait_for(
-                _destroy_model_loop(model_name, controller), timeout=timeout
+                _destroy_model_gracefully(model_name, controller), timeout=120
             )
         except asyncio.TimeoutError:
-            raise Exception(
-                "Timeout waiting for model {} to be destroyed".format(model_name)
-            )
+            await _destroy_model_forcefully(model_name, controller)
         except juju.errors.JujuError as e:
             if any("has been removed" in error for error in e.errors):
                 return
-- 
2.17.1