Feature 10974: Add juju instantiation params.
[osm/N2VC.git] / n2vc / libjuju.py
index 1785caa..55ca859 100644 (file)
 
 import asyncio
 import logging
+import os
 import typing
+import yaml
 
 import time
 
 import juju.errors
+from juju.bundle import BundleHandler
 from juju.model import Model
 from juju.machine import Machine
 from juju.application import Application
 from juju.unit import Unit
+from juju.url import URL
+from juju.version import DEFAULT_ARCHITECTURE
 from juju.client._definitions import (
     FullStatus,
     QueryApplicationOffersResults,
@@ -549,27 +554,122 @@ class Libjuju:
         return machine_id
 
     async def deploy(
-        self, uri: str, model_name: str, wait: bool = True, timeout: float = 3600
+        self,
+        uri: str,
+        model_name: str,
+        wait: bool = True,
+        timeout: float = 3600,
+        instantiation_params: dict = None,
     ):
         """
         Deploy bundle or charm: Similar to the juju CLI command `juju deploy`
 
-        :param: uri:            Path or Charm Store uri in which the charm or bundle can be found
-        :param: model_name:     Model name
-        :param: wait:           Indicates whether to wait or not until all applications are active
-        :param: timeout:        Time in seconds to wait until all applications are active
+        :param uri:            Path or Charm Store uri in which the charm or bundle can be found
+        :param model_name:     Model name
+        :param wait:           Indicates whether to wait or not until all applications are active
+        :param timeout:        Time in seconds to wait until all applications are active
+        :param instantiation_params: To be applied as overlay bundle over primary bundle.
         """
         controller = await self.get_controller()
         model = await self.get_model(controller, model_name)
+        overlays = []
         try:
-            await model.deploy(uri, trust=True)
+            await self._validate_instantiation_params(uri, model, instantiation_params)
+            overlays = self._get_overlays(model_name, instantiation_params)
+            await model.deploy(uri, trust=True, overlays=overlays)
             if wait:
                 await JujuModelWatcher.wait_for_model(model, timeout=timeout)
                 self.log.debug("All units active in model {}".format(model_name))
         finally:
+            self._remove_overlay_file(overlays)
             await self.disconnect_model(model)
             await self.disconnect_controller(controller)
 
+    async def _validate_instantiation_params(
+        self, uri: str, model, instantiation_params: dict
+    ) -> None:
+        """Checks if all the applications in instantiation_params
+        exist ins the original bundle.
+
+        Raises:
+            JujuApplicationNotFound if there is an invalid app in
+            the instantiation params.
+        """
+        overlay_apps = self._get_apps_in_instantiation_params(instantiation_params)
+        if not overlay_apps:
+            return
+        original_apps = await self._get_apps_in_original_bundle(uri, model)
+        if not all(app in original_apps for app in overlay_apps):
+            raise JujuApplicationNotFound(
+                "Cannot find application {} in original bundle {}".format(
+                    overlay_apps, original_apps
+                )
+            )
+
+    async def _get_apps_in_original_bundle(self, uri: str, model) -> set:
+        """Bundle is downloaded in BundleHandler.fetch_plan.
+        That method takes care of opening and exception handling.
+
+        Resolve method gets all the information regarding the channel,
+        track, revision, type, source.
+
+        Returns:
+            Set with the names of the applications in original bundle.
+        """
+        url = URL.parse(uri)
+        architecture = DEFAULT_ARCHITECTURE  # only AMD64 is allowed
+        res = await model.deploy_types[str(url.schema)].resolve(
+            url, architecture, entity_url=uri
+        )
+        handler = BundleHandler(model, trusted=True, forced=False)
+        await handler.fetch_plan(url, res.origin)
+        return handler.applications
+
+    def _get_apps_in_instantiation_params(self, instantiation_params: dict) -> list:
+        """Extract applications key in instantiation params.
+
+        Returns:
+            List with the names of the applications in instantiation params.
+
+        Raises:
+            JujuError if applications key is not found.
+        """
+        if not instantiation_params:
+            return []
+        try:
+            return [key for key in instantiation_params.get("applications")]
+        except Exception as e:
+            raise JujuError("Invalid overlay format. {}".format(str(e)))
+
+    def _get_overlays(self, model_name: str, instantiation_params: dict) -> list:
+        """Creates a temporary overlay file which includes the instantiation params.
+        Only one overlay file is created.
+
+        Returns:
+            List with one overlay filename. Empty list if there are no instantiation params.
+        """
+        if not instantiation_params:
+            return []
+        file_name = model_name + "-overlay.yaml"
+        self._write_overlay_file(file_name, instantiation_params)
+        return [file_name]
+
+    def _write_overlay_file(self, file_name: str, instantiation_params: dict) -> None:
+        with open(file_name, "w") as file:
+            yaml.dump(instantiation_params, file)
+
+    def _remove_overlay_file(self, overlay: list) -> None:
+        """Overlay contains either one or zero file names."""
+        if not overlay:
+            return
+        try:
+            filename = overlay[0]
+            os.remove(filename)
+        except OSError as e:
+            self.log.warning(
+                "Overlay file {} could not be removed: {}".format(filename, e)
+            )
+
     async def add_unit(
         self,
         application_name: str,