def decide_version()

in azurelinuxagent/ga/exthandlers.py [0:0]

• 43 lines of code
• 18 McCabe index (conditional complexity)

    def decide_version(self, target_state, extension, gs_activity_id):
        self.logger.verbose("Decide which version to use")
        try:
            manifest = self.protocol.get_goal_state().fetch_extension_manifest(self.ext_handler.name, self.ext_handler.manifest_uris)
            pkg_list = manifest.pkg_list
        except ProtocolError as e:
            raise ExtensionError("Failed to get ext handler pkgs", e)
        except ExtensionDownloadError:
            self.set_operation(WALAEventOperation.Download)
            raise

        # Determine the desired and installed versions
        requested_version = FlexibleVersion(str(self.ext_handler.version))
        installed_version_string = self.get_installed_version()
        installed_version = requested_version if installed_version_string is None else FlexibleVersion(installed_version_string)

        # Divide packages
        # - Find the installed package (its version must exactly match)
        # - Find the internal candidate (its version must exactly match)
        # - Separate the public packages
        selected_pkg = None
        installed_pkg = None
        pkg_list.versions.sort(key=lambda p: FlexibleVersion(p.version))
        for pkg in pkg_list.versions:
            pkg_version = FlexibleVersion(pkg.version)
            if pkg_version == installed_version:
                installed_pkg = pkg
            if requested_version.matches(pkg_version):
                selected_pkg = pkg

        # Finally, update the version only if not downgrading
        # Note:
        #  - A downgrade, which will be bound to the same major version,
        #    is allowed if the installed version is no longer available
        if target_state in (ExtensionRequestedState.Uninstall, ExtensionRequestedState.Disabled):
            if installed_pkg is None:
                msg = "Failed to find installed version: {0} of Handler: {1}  in handler manifest to uninstall.".format(
                    installed_version, self.ext_handler.name)
                self.logger.warn(msg)
            self.pkg = installed_pkg
            self.ext_handler.version = str(installed_version) \
                if installed_version is not None else None
        else:
            self.pkg = selected_pkg
            if self.pkg is not None:
                if self.ext_handler.version != str(selected_pkg.version):
                    # The Agent should not change the version requested by the Goal State. Send telemetry if this happens.
                    event.info(
                        WALAEventOperation.RequestedVersionMismatch,
                        'Goal State requesting {0} version {1}, but Agent overriding with version {2} [Activity ID: {3}]',  self.ext_handler.name, self.ext_handler.version, selected_pkg.version, gs_activity_id)
                self.ext_handler.version = str(selected_pkg.version)

        if self.pkg is not None:
            self.logger.verbose("Use version: {0}", self.pkg.version)

        # We reset the logger here incase the handler version changes
        if not requested_version.matches(FlexibleVersion(self.ext_handler.version)):
            self.set_logger(extension=extension)

        return self.pkg