/*
Copyright 2014 The Kubernetes Authors All rights reserved.

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 (
	"strings"
	"time"

	"k8s.io/kubernetes/pkg/admission"
	"k8s.io/kubernetes/pkg/api"
	"k8s.io/kubernetes/pkg/api/unversioned"
	apiutil "k8s.io/kubernetes/pkg/api/util"
	"k8s.io/kubernetes/pkg/api/validation"
	"k8s.io/kubernetes/pkg/apimachinery/registered"
	"k8s.io/kubernetes/pkg/apiserver"
	"k8s.io/kubernetes/pkg/genericapiserver"
	kubeletclient "k8s.io/kubernetes/pkg/kubelet/client"
	"k8s.io/kubernetes/pkg/master/ports"

	"github.com/spf13/pflag"
)

// APIServer runs a kubernetes api server.
type APIServer struct {
	*genericapiserver.ServerRunOptions
	AdmissionControl           string
	AdmissionControlConfigFile string
	AllowPrivileged            bool
	AuthorizationMode          string
	AuthorizationConfig        apiserver.AuthorizationConfig
	BasicAuthFile              string
	DeleteCollectionWorkers    int
	DeprecatedStorageVersion   string
	EtcdServersOverrides       []string
	EventTTL                   time.Duration
	KeystoneURL                string
	KubeletConfig              kubeletclient.KubeletClientConfig
	MasterServiceNamespace     string
	MaxConnectionBytesPerSec   int64
	OIDCCAFile                 string
	OIDCClientID               string
	OIDCIssuerURL              string
	OIDCUsernameClaim          string
	OIDCGroupsClaim            string
	SSHKeyfile                 string
	SSHUser                    string
	ServiceAccountKeyFile      string
	ServiceAccountLookup       bool
	StorageVersions            string
	// The default values for StorageVersions. StorageVersions overrides
	// these; you can change this if you want to change the defaults (e.g.,
	// for testing). This is not actually exposed as a flag.
	DefaultStorageVersions string
	TokenAuthFile          string
	WatchCacheSizes        []string
}

// NewAPIServer creates a new APIServer object with default parameters
func NewAPIServer() *APIServer {
	s := APIServer{
		ServerRunOptions:        genericapiserver.NewServerRunOptions(),
		AdmissionControl:        "AlwaysAdmit",
		AuthorizationMode:       "AlwaysAllow",
		DeleteCollectionWorkers: 1,
		EventTTL:                1 * time.Hour,
		MasterServiceNamespace:  api.NamespaceDefault,
		StorageVersions:         registered.AllPreferredGroupVersions(),
		DefaultStorageVersions:  registered.AllPreferredGroupVersions(),
		KubeletConfig: kubeletclient.KubeletClientConfig{
			Port:        ports.KubeletPort,
			EnableHttps: true,
			HTTPTimeout: time.Duration(5) * time.Second,
		},
	}
	return &s
}

// dest must be a map of group to groupVersion.
func mergeGroupVersionIntoMap(gvList string, dest map[string]unversioned.GroupVersion) error {
	for _, gvString := range strings.Split(gvList, ",") {
		if gvString == "" {
			continue
		}
		// We accept two formats. "group/version" OR
		// "group=group/version". The latter is used when types
		// move between groups.
		if !strings.Contains(gvString, "=") {
			gv, err := unversioned.ParseGroupVersion(gvString)
			if err != nil {
				return err
			}
			dest[gv.Group] = gv

		} else {
			parts := strings.SplitN(gvString, "=", 2)
			gv, err := unversioned.ParseGroupVersion(parts[1])
			if err != nil {
				return err
			}
			dest[parts[0]] = gv
		}
	}

	return nil
}

// StorageGroupsToEncodingVersion returns a map from group name to group version,
// computed from the s.DeprecatedStorageVersion and s.StorageVersions flags.
// TODO: can we move the whole storage version concept to the generic apiserver?
func (s *APIServer) StorageGroupsToEncodingVersion() (map[string]unversioned.GroupVersion, error) {
	storageVersionMap := map[string]unversioned.GroupVersion{}
	if s.DeprecatedStorageVersion != "" {
		storageVersionMap[""] = unversioned.GroupVersion{Group: apiutil.GetGroup(s.DeprecatedStorageVersion), Version: apiutil.GetVersion(s.DeprecatedStorageVersion)}
	}

	// First, get the defaults.
	if err := mergeGroupVersionIntoMap(s.DefaultStorageVersions, storageVersionMap); err != nil {
		return nil, err
	}
	// Override any defaults with the user settings.
	if err := mergeGroupVersionIntoMap(s.StorageVersions, storageVersionMap); err != nil {
		return nil, err
	}

	return storageVersionMap, nil
}

// AddFlags adds flags for a specific APIServer to the specified FlagSet
func (s *APIServer) AddFlags(fs *pflag.FlagSet) {
	// Add the generic flags.
	s.ServerRunOptions.AddFlags(fs)
	// Note: the weird ""+ in below lines seems to be the only way to get gofmt to
	// arrange these text blocks sensibly. Grrr.
	fs.StringVar(&s.DeprecatedStorageVersion, "storage-version", s.DeprecatedStorageVersion, "The version to store the legacy v1 resources with. Defaults to server preferred")
	fs.MarkDeprecated("storage-version", "--storage-version is deprecated and will be removed when the v1 API is retired. See --storage-versions instead.")
	fs.StringVar(&s.StorageVersions, "storage-versions", s.StorageVersions, "The per-group version to store resources in. "+
		"Specified in the format \"group1/version1,group2/version2,...\". "+
		"In the case where objects are moved from one group to the other, you may specify the format \"group1=group2/v1beta1,group3/v1beta1,...\". "+
		"You only need to pass the groups you wish to change from the defaults. "+
		"It defaults to a list of preferred versions of all registered groups, which is derived from the KUBE_API_VERSIONS environment variable.")
	fs.DurationVar(&s.EventTTL, "event-ttl", s.EventTTL, "Amount of time to retain events. Default 1 hour.")
	fs.StringVar(&s.BasicAuthFile, "basic-auth-file", s.BasicAuthFile, "If set, the file that will be used to admit requests to the secure port of the API server via http basic authentication.")
	fs.StringVar(&s.TokenAuthFile, "token-auth-file", s.TokenAuthFile, "If set, the file that will be used to secure the secure port of the API server via token authentication.")
	fs.StringVar(&s.OIDCIssuerURL, "oidc-issuer-url", s.OIDCIssuerURL, "The URL of the OpenID issuer, only HTTPS scheme will be accepted. If set, it will be used to verify the OIDC JSON Web Token (JWT)")
	fs.StringVar(&s.OIDCClientID, "oidc-client-id", s.OIDCClientID, "The client ID for the OpenID Connect client, must be set if oidc-issuer-url is set")
	fs.StringVar(&s.OIDCCAFile, "oidc-ca-file", s.OIDCCAFile, "If set, the OpenID server's certificate will be verified by one of the authorities in the oidc-ca-file, otherwise the host's root CA set will be used")
	fs.StringVar(&s.OIDCUsernameClaim, "oidc-username-claim", "sub", ""+
		"The OpenID claim to use as the user name. Note that claims other than the default ('sub') is not "+
		"guaranteed to be unique and immutable. This flag is experimental, please see the authentication documentation for further details.")
	fs.StringVar(&s.OIDCGroupsClaim, "oidc-groups-claim", "", "If provided, the name of a custom OpenID Connect claim for specifying user groups. The claim value is expected to be an array of strings. This flag is experimental, please see the authentication documentation for further details.")
	fs.StringVar(&s.ServiceAccountKeyFile, "service-account-key-file", s.ServiceAccountKeyFile, "File containing PEM-encoded x509 RSA private or public key, used to verify ServiceAccount tokens. If unspecified, --tls-private-key-file is used.")
	fs.BoolVar(&s.ServiceAccountLookup, "service-account-lookup", s.ServiceAccountLookup, "If true, validate ServiceAccount tokens exist in etcd as part of authentication.")
	fs.StringVar(&s.KeystoneURL, "experimental-keystone-url", s.KeystoneURL, "If passed, activates the keystone authentication plugin")
	fs.StringVar(&s.AuthorizationMode, "authorization-mode", s.AuthorizationMode, "Ordered list of plug-ins to do authorization on secure port. Comma-delimited list of: "+strings.Join(apiserver.AuthorizationModeChoices, ","))
	fs.StringVar(&s.AuthorizationConfig.PolicyFile, "authorization-policy-file", s.AuthorizationConfig.PolicyFile, "File with authorization policy in csv format, used with --authorization-mode=ABAC, on the secure port.")
	fs.StringVar(&s.AuthorizationConfig.WebhookConfigFile, "authorization-webhook-config-file", s.AuthorizationConfig.WebhookConfigFile, "File with webhook configuration in kubeconfig format, used with --authorization-mode=Webhook. The API server will query the remote service to determine access on the API server's secure port.")
	fs.StringVar(&s.AdmissionControl, "admission-control", s.AdmissionControl, "Ordered list of plug-ins to do admission control of resources into cluster. Comma-delimited list of: "+strings.Join(admission.GetPlugins(), ", "))
	fs.StringVar(&s.AdmissionControlConfigFile, "admission-control-config-file", s.AdmissionControlConfigFile, "File with admission control configuration.")
	fs.StringSliceVar(&s.EtcdServersOverrides, "etcd-servers-overrides", s.EtcdServersOverrides, "Per-resource etcd servers overrides, comma separated. The individual override format: group/resource#servers, where servers are http://ip:port, semicolon separated.")
	fs.BoolVar(&s.AllowPrivileged, "allow-privileged", s.AllowPrivileged, "If true, allow privileged containers.")
	fs.StringVar(&s.MasterServiceNamespace, "master-service-namespace", s.MasterServiceNamespace, "The namespace from which the kubernetes master services should be injected into pods")
	fs.IntVar(&s.DeleteCollectionWorkers, "delete-collection-workers", s.DeleteCollectionWorkers, "Number of workers spawned for DeleteCollection call. These are used to speed up namespace cleanup.")
	fs.StringVar(&s.SSHUser, "ssh-user", s.SSHUser, "If non-empty, use secure SSH proxy to the nodes, using this user name")
	fs.StringVar(&s.SSHKeyfile, "ssh-keyfile", s.SSHKeyfile, "If non-empty, use secure SSH proxy to the nodes, using this user keyfile")
	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")
	// Kubelet related flags:
	fs.BoolVar(&s.KubeletConfig.EnableHttps, "kubelet-https", s.KubeletConfig.EnableHttps, "Use https for kubelet connections")
	fs.UintVar(&s.KubeletConfig.Port, "kubelet-port", s.KubeletConfig.Port, "Kubelet port")
	fs.MarkDeprecated("kubelet-port", "kubelet-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.")
	// TODO: delete this flag as soon as we identify and fix all clients that send malformed updates, like #14126.
	fs.BoolVar(&validation.RepairMalformedUpdates, "repair-malformed-updates", validation.RepairMalformedUpdates, "If true, server will do its best to fix the update request to pass the validation, e.g., setting empty UID in update request to its existing value. This flag can be turned off after we fix all the clients that send malformed updates.")
	fs.StringSliceVar(&s.WatchCacheSizes, "watch-cache-sizes", s.WatchCacheSizes, "List of watch cache sizes for every resource (pods, nodes, etc.), comma separated. The individual override format: resource#size, where size is a number. It takes effect when watch-cache is enabled.")
}
