/*
Copyright 2017 The Kubernetes Authors.

Licensed 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 options contains flags and options for initializing kube-apiserver
package options

import (
	"fmt"
	"net"

	utilnet "k8s.io/apimachinery/pkg/util/net"
	genericoptions "k8s.io/apiserver/pkg/server/options"
)

// NewSecureServingOptions gives default values for the kube-apiserver which are not the options wanted by
// "normal" API servers running on the platform
func NewSecureServingOptions() *genericoptions.SecureServingOptionsWithLoopback {
	o := genericoptions.SecureServingOptions{
		BindAddress: net.ParseIP("0.0.0.0"),
		BindPort:    6443,
		Required:    true,
		ServerCert: genericoptions.GeneratableKeyCert{
			PairName:      "apiserver",
			CertDirectory: "/var/run/kubernetes",
		},
	}
	return o.WithLoopback()
}

// NewInsecureServingOptions gives default values for the kube-apiserver.
// TODO: switch insecure serving off by default
func NewInsecureServingOptions() *genericoptions.DeprecatedInsecureServingOptionsWithLoopback {
	o := genericoptions.DeprecatedInsecureServingOptions{
		BindAddress: net.ParseIP("127.0.0.1"),
		BindPort:    8080,
	}
	return o.WithLoopback()
}

// DefaultAdvertiseAddress sets the field AdvertiseAddress if
// unset. The field will be set based on the SecureServingOptions. If
// the SecureServingOptions is not present, DefaultExternalAddress
// will fall back to the insecure ServingOptions.
func DefaultAdvertiseAddress(s *genericoptions.ServerRunOptions, insecure *genericoptions.DeprecatedInsecureServingOptions) error {
	if insecure == nil {
		return nil
	}

	if s.AdvertiseAddress == nil || s.AdvertiseAddress.IsUnspecified() {
		hostIP, err := utilnet.ChooseBindAddress(insecure.BindAddress)
		if err != nil {
			return fmt.Errorf("unable to find suitable network address.error='%v'. "+
				"Try to set the AdvertiseAddress directly or provide a valid BindAddress to fix this", err)
		}
		s.AdvertiseAddress = hostIP
	}

	return nil
}