updater.go

/*
Copyright (C) 2019 Synopsys, Inc.

Licensed to the Apache Software Foundation (ASF) under one
or more contributor license agreements. See the NOTICE file
distributed with this work for additional information
regarding copyright ownership. The ASF licenses this file
to you under the Apache License, Version 2.0 (the
"License"); you may not use this file except in compliance
with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing,
software distributed under the License is distributed on an
"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
KIND, either express or implied. See the License for the
specific language governing permissions and limitations
under the License.
*/

package crdupdater

import (
	"github.com/juju/errors"
)

// UpdateComponents consist of methods to add, patch or remove the components for update events
type UpdateComponents interface {
	buildNewAndOldObject() error
	add(bool) (bool, error)
	get(name string) (interface{}, error)
	list() (interface{}, error)
	delete(name string) error
	remove() error
	patch(interface{}, bool) (bool, error)
}

// Updater handles in updating the components
type Updater struct {
	updaters  []UpdateComponents
	dryRun    bool
	isPatched bool
}

// NewUpdater will create the specification that is used for updating the components
func NewUpdater(dryRun bool, isPatched bool) *Updater {
	updater := Updater{
		updaters:  make([]UpdateComponents, 0),
		dryRun:    dryRun,
		isPatched: isPatched,
	}
	return &updater
}

// AddUpdater will add the updater to the list
func (u *Updater) AddUpdater(updater UpdateComponents) {
	if updater != nil {
		u.updaters = append(u.updaters, updater)
	}
}

// Update add or remove the components
func (u *Updater) Update() (bool, error) {
	isPatched := false
	for _, updater := range u.updaters {
		if !u.dryRun {
			err := updater.buildNewAndOldObject()
			if err != nil {
				return false, errors.Annotatef(err, "build components:")
			}
		}
		isUpdated, err := updater.add(isPatched)
		isPatched = isPatched || u.isPatched || isUpdated
		if err != nil {
			return false, errors.Annotatef(err, "add/patch components:")
		}
		if !u.dryRun {
			err = updater.remove()
			if err != nil {
				return false, errors.Annotatef(err, "remove components:")
			}
		}
	}
	return isPatched, nil
}