/*
Copyright 2014 The Kubernetes Authors.
Copyright 2020 Authors of Arktos - file modified.

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 an apiserver
package options

import (
	"net"
	"strings"
	"time"

	utilnet "k8s.io/apimachinery/pkg/util/net"
	genericoptions "k8s.io/apiserver/pkg/server/options"
	"k8s.io/apiserver/pkg/storage/storagebackend"
	cliflag "k8s.io/component-base/cli/flag"
	api "k8s.io/kubernetes/pkg/apis/core"
	_ "k8s.io/kubernetes/pkg/features" // add the kubernetes feature gates
	kubeoptions "k8s.io/kubernetes/pkg/kubeapiserver/options"
	kubeletclient "k8s.io/kubernetes/pkg/kubelet/client"
	"k8s.io/kubernetes/pkg/master/ports"
	"k8s.io/kubernetes/pkg/master/reconcilers"
	"k8s.io/kubernetes/pkg/serviceaccount"
)

// ServerRunOptions runs a kubernetes api server.
type ServerRunOptions struct {
	GenericServerRunOptions *genericoptions.ServerRunOptions
	Etcd                    *genericoptions.EtcdOptions
	SecureServing           *genericoptions.SecureServingOptionsWithLoopback
	InsecureServing         *genericoptions.DeprecatedInsecureServingOptionsWithLoopback
	Audit                   *genericoptions.AuditOptions
	Features                *genericoptions.FeatureOptions
	Admission               *kubeoptions.AdmissionOptions
	Authentication          *kubeoptions.BuiltInAuthenticationOptions
	Authorization           *kubeoptions.BuiltInAuthorizationOptions
	CloudProvider           *kubeoptions.CloudProviderOptions
	APIEnablement           *genericoptions.APIEnablementOptions

	AllowPrivileged           bool
	EnableLogsHandler         bool
	EventTTL                  time.Duration
	KubeletConfig             kubeletclient.KubeletClientConfig
	KubernetesServiceNodePort int
	MaxConnectionBytesPerSec  int64
	ServiceClusterIPRange     net.IPNet // TODO: make this a list
	ServiceNodePortRange      utilnet.PortRange
	ServiceClusterSubnet      string
	SSHKeyfile                string
	SSHUser                   string

	ProxyClientCertFile string
	ProxyClientKeyFile  string

	EnableAggregatorRouting bool

	MasterCount            int
	EndpointReconcilerType string

	ServiceAccountSigningKeyFile     string
	ServiceAccountIssuer             serviceaccount.TokenGenerator
	ServiceAccountTokenMaxExpiration time.Duration

	ServiceGroupId string
}

// NewServerRunOptions creates a new ServerRunOptions object with default parameters
func NewServerRunOptions() *ServerRunOptions {
	s := ServerRunOptions{
		GenericServerRunOptions: genericoptions.NewServerRunOptions(),
		Etcd:                    genericoptions.NewEtcdOptions(storagebackend.NewDefaultConfig(kubeoptions.DefaultEtcdPathPrefix, nil)),
		SecureServing:           kubeoptions.NewSecureServingOptions(),
		InsecureServing:         kubeoptions.NewInsecureServingOptions(),
		Audit:                   genericoptions.NewAuditOptions(),
		Features:                genericoptions.NewFeatureOptions(),
		Admission:               kubeoptions.NewAdmissionOptions(),
		Authentication:          kubeoptions.NewBuiltInAuthenticationOptions().WithAll(),
		Authorization:           kubeoptions.NewBuiltInAuthorizationOptions(),
		CloudProvider:           kubeoptions.NewCloudProviderOptions(),
		APIEnablement:           genericoptions.NewAPIEnablementOptions(),

		EnableLogsHandler:      true,
		EventTTL:               1 * time.Hour,
		MasterCount:            1,
		EndpointReconcilerType: string(reconcilers.LeaseEndpointReconcilerType),
		KubeletConfig: kubeletclient.KubeletClientConfig{
			Port:         ports.KubeletPort,
			ReadOnlyPort: ports.KubeletReadOnlyPort,
			PreferredAddressTypes: []string{
				// --override-hostname
				string(api.NodeHostName),

				// internal, preferring DNS if reported
				string(api.NodeInternalDNS),
				string(api.NodeInternalIP),

				// external, preferring DNS if reported
				string(api.NodeExternalDNS),
				string(api.NodeExternalIP),
			},
			EnableHttps: true,
			HTTPTimeout: time.Duration(5) * time.Second,
		},
		ServiceNodePortRange: kubeoptions.DefaultServiceNodePortRange,
	}
	s.ServiceClusterIPRange = kubeoptions.DefaultServiceIPCIDR

	// Overwrite the default for storage data format.
	s.Etcd.DefaultStorageMediaType = "application/vnd.kubernetes.protobuf"

	return &s
}

// Flags returns flags for a specific APIServer by section name
func (s *ServerRunOptions) Flags() (fss cliflag.NamedFlagSets) {
	// Add the generic flags.
	s.GenericServerRunOptions.AddUniversalFlags(fss.FlagSet("generic"))
	s.Etcd.AddFlags(fss.FlagSet("etcd"))
	s.SecureServing.AddFlags(fss.FlagSet("secure serving"))
	s.InsecureServing.AddFlags(fss.FlagSet("insecure serving"))
	s.InsecureServing.AddUnqualifiedFlags(fss.FlagSet("insecure serving")) // TODO: remove it until kops stops using `--address`
	s.Audit.AddFlags(fss.FlagSet("auditing"))
	s.Features.AddFlags(fss.FlagSet("features"))
	s.Authentication.AddFlags(fss.FlagSet("authentication"))
	s.Authorization.AddFlags(fss.FlagSet("authorization"))
	s.CloudProvider.AddFlags(fss.FlagSet("cloud provider"))
	s.APIEnablement.AddFlags(fss.FlagSet("api enablement"))
	s.Admission.AddFlags(fss.FlagSet("admission"))

	// Note: the weird ""+ in below lines seems to be the only way to get gofmt to
	// arrange these text blocks sensibly. Grrr.
	fs := fss.FlagSet("misc")
	fs.DurationVar(&s.EventTTL, "event-ttl", s.EventTTL,
		"Amount of time to retain events.")

	fs.BoolVar(&s.AllowPrivileged, "allow-privileged", s.AllowPrivileged,
		"If true, allow privileged containers. [default=false]")

	fs.BoolVar(&s.EnableLogsHandler, "enable-logs-handler", s.EnableLogsHandler,
		"If true, install a /logs handler for the apiserver logs.")
	fs.MarkDeprecated("enable-logs-handler", "This flag will be removed in v1.19")

	// Deprecated in release 1.9
	fs.StringVar(&s.SSHUser, "ssh-user", s.SSHUser,
		"If non-empty, use secure SSH proxy to the nodes, using this user name")
	fs.MarkDeprecated("ssh-user", "This flag will be removed in a future version.")

	// Deprecated in release 1.9
	fs.StringVar(&s.SSHKeyfile, "ssh-keyfile", s.SSHKeyfile,
		"If non-empty, use secure SSH proxy to the nodes, using this user keyfile")
	fs.MarkDeprecated("ssh-keyfile", "This flag will be removed in a future version.")

	fs.Int64Var(&s.MaxConnectionBytesPerSec, "max-connection-bytes-per-sec", s.MaxConnectionBytesPerSec, ""+
		"If non-zero, throttle each user connection to this number of bytes/sec. "+
		"Currently only applies to long-running requests.")

	fs.IntVar(&s.MasterCount, "apiserver-count", s.MasterCount,
		"The number of apiservers running in the cluster, must be a positive number. (In use when --endpoint-reconciler-type=master-count is enabled.)")

	fs.StringVar(&s.EndpointReconcilerType, "endpoint-reconciler-type", string(s.EndpointReconcilerType),
		"Use an endpoint reconciler ("+strings.Join(reconcilers.AllTypes.Names(), ", ")+")")

	// See #14282 for details on how to test/try this option out.
	// TODO: remove this comment once this option is tested in CI.
	fs.IntVar(&s.KubernetesServiceNodePort, "kubernetes-service-node-port", s.KubernetesServiceNodePort, ""+
		"If non-zero, the Kubernetes master service (which apiserver creates/maintains) will be "+
		"of type NodePort, using this as the value of the port. If zero, the Kubernetes master "+
		"service will be of type ClusterIP.")

	fs.IPNetVar(&s.ServiceClusterIPRange, "service-cluster-ip-range", s.ServiceClusterIPRange, ""+
		"A CIDR notation IP range from which to assign service cluster IPs. This must not "+
		"overlap with any IP ranges assigned to nodes for pods.")

	fs.Var(&s.ServiceNodePortRange, "service-node-port-range", ""+
		"A port range to reserve for services with NodePort visibility. "+
		"Example: '30000-32767'. Inclusive at both ends of the range.")

	fs.StringVar(&s.ServiceClusterSubnet, "service-cluster-subnet", s.ServiceClusterSubnet, ""+
		"A Subnet name/ID from which to assign service cluster IPs. This must not "+
		"be the subnet assigned to nodes for pods. "+
		"Note this subnet if defined will OVERWRITE service-cluster-ip-range.")

	// Kubelet related flags:
	fs.BoolVar(&s.KubeletConfig.EnableHttps, "kubelet-https", s.KubeletConfig.EnableHttps,
		"Use https for kubelet connections.")

	fs.StringSliceVar(&s.KubeletConfig.PreferredAddressTypes, "kubelet-preferred-address-types", s.KubeletConfig.PreferredAddressTypes,
		"List of the preferred NodeAddressTypes to use for kubelet connections.")

	fs.UintVar(&s.KubeletConfig.Port, "kubelet-port", s.KubeletConfig.Port,
		"DEPRECATED: kubelet port.")
	fs.MarkDeprecated("kubelet-port", "kubelet-port is deprecated and will be removed.")

	fs.UintVar(&s.KubeletConfig.ReadOnlyPort, "kubelet-read-only-port", s.KubeletConfig.ReadOnlyPort,
		"DEPRECATED: kubelet read only port.")
	fs.MarkDeprecated("kubelet-read-only-port", "kubelet-read-only-port is deprecated and will be removed.")

	fs.DurationVar(&s.KubeletConfig.HTTPTimeout, "kubelet-timeout", s.KubeletConfig.HTTPTimeout,
		"Timeout for kubelet operations.")

	fs.StringVar(&s.KubeletConfig.CertFile, "kubelet-client-certificate", s.KubeletConfig.CertFile,
		"Path to a client cert file for TLS.")

	fs.StringVar(&s.KubeletConfig.KeyFile, "kubelet-client-key", s.KubeletConfig.KeyFile,
		"Path to a client key file for TLS.")

	fs.StringVar(&s.KubeletConfig.CAFile, "kubelet-certificate-authority", s.KubeletConfig.CAFile,
		"Path to a cert file for the certificate authority.")

	fs.StringVar(&s.ProxyClientCertFile, "proxy-client-cert-file", s.ProxyClientCertFile, ""+
		"Client certificate used to prove the identity of the aggregator or kube-apiserver "+
		"when it must call out during a request. This includes proxying requests to a user "+
		"api-server and calling out to webhook admission plugins. It is expected that this "+
		"cert includes a signature from the CA in the --requestheader-client-ca-file flag. "+
		"That CA is published in the 'extension-apiserver-authentication' configmap in "+
		"the kube-system namespace. Components receiving calls from kube-aggregator should "+
		"use that CA to perform their half of the mutual TLS verification.")
	fs.StringVar(&s.ProxyClientKeyFile, "proxy-client-key-file", s.ProxyClientKeyFile, ""+
		"Private key for the client certificate used to prove the identity of the aggregator or kube-apiserver "+
		"when it must call out during a request. This includes proxying requests to a user "+
		"api-server and calling out to webhook admission plugins.")

	fs.BoolVar(&s.EnableAggregatorRouting, "enable-aggregator-routing", s.EnableAggregatorRouting,
		"Turns on aggregator routing requests to endpoints IP rather than cluster IP.")

	fs.StringVar(&s.ServiceAccountSigningKeyFile, "service-account-signing-key-file", s.ServiceAccountSigningKeyFile, ""+
		"Path to the file that contains the current private key of the service account token issuer. The issuer will sign issued ID tokens with this private key. (Requires the 'TokenRequest' feature gate.)")

	fs.StringVar(&s.ServiceGroupId, "service-group-id", s.ServiceGroupId, ""+
		"An optional field indicating the service group that this api server is belong to. Service group id is used to partition "+
		"tenant data read from etcd. Default to service group 0. If there is no data partition for the service group, this api "+
		"server will take all data from etcd")

	return fss
}
