kubesphere/vendor/istio.io/api/networking/v1beta1/service_entry.proto

// Copyright 2020 Istio 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.

syntax = "proto3";

import "google/api/field_behavior.proto";
import "networking/v1beta1/gateway.proto";
import "networking/v1beta1/sidecar.proto";
import "networking/v1beta1/workload_entry.proto";

// $schema: istio.networking.v1beta1.ServiceEntry
// $title: Service Entry
// $description: Configuration affecting service registry.
// $location: https://istio.io/docs/reference/config/networking/service-entry.html
// $aliases: [/docs/reference/config/networking/v1beta1/service-entry]

// `ServiceEntry` enables adding additional entries into Istio's
// internal service registry, so that auto-discovered services in the
// mesh can access/route to these manually specified services. A
// service entry describes the properties of a service (DNS name,
// VIPs, ports, protocols, endpoints). These services could be
// external to the mesh (e.g., web APIs) or mesh-internal services
// that are not part of the platform's service registry (e.g., a set
// of VMs talking to services in Kubernetes). In addition, the
// endpoints of a service entry can also be dynamically selected by
// using the `workloadSelector` field. These endpoints can be VM
// workloads declared using the `WorkloadEntry` object or Kubernetes
// pods. The ability to select both pods and VMs under a single
// service allows for migration of services from VMs to Kubernetes
// without having to change the existing DNS names associated with the
// services.
//
// The following example declares a few external APIs accessed by internal
// applications over HTTPS. The sidecar inspects the SNI value in the
// ClientHello message to route to the appropriate external service.
//
// {{<tabset category-name="example">}}
// {{<tab name="v1alpha3" category-value="v1alpha3">}}
// ```yaml
// apiVersion: networking.istio.io/v1alpha3
// kind: ServiceEntry
// metadata:
//   name: external-svc-https
// spec:
//   hosts:
//   - api.dropboxapi.com
//   - www.googleapis.com
//   - api.facebook.com
//   location: MESH_EXTERNAL
//   ports:
//   - number: 443
//     name: https
//     protocol: TLS
//   resolution: DNS
// ```
// {{</tab>}}
//
// {{<tab name="v1beta1" category-value="v1beta1">}}
// ```yaml
// apiVersion: networking.istio.io/v1beta1
// kind: ServiceEntry
// metadata:
//   name: external-svc-https
// spec:
//   hosts:
//   - api.dropboxapi.com
//   - www.googleapis.com
//   - api.facebook.com
//   location: MESH_EXTERNAL
//   ports:
//   - number: 443
//     name: https
//     protocol: TLS
//   resolution: DNS
// ```
// {{</tab>}}
// {{</tabset>}}
//
// The following configuration adds a set of MongoDB instances running on
// unmanaged VMs to Istio's registry, so that these services can be treated
// as any other service in the mesh. The associated DestinationRule is used
// to initiate mTLS connections to the database instances.
//
// {{<tabset category-name="example">}}
// {{<tab name="v1alpha3" category-value="v1alpha3">}}
// ```yaml
// apiVersion: networking.istio.io/v1alpha3
// kind: ServiceEntry
// metadata:
//   name: external-svc-mongocluster
// spec:
//   hosts:
//   - mymongodb.somedomain # not used
//   addresses:
//   - 192.192.192.192/24 # VIPs
//   ports:
//   - number: 27018
//     name: mongodb
//     protocol: MONGO
//   location: MESH_INTERNAL
//   resolution: STATIC
//   endpoints:
//   - address: 2.2.2.2
//   - address: 3.3.3.3
// ```
// {{</tab>}}
//
// {{<tab name="v1beta1" category-value="v1beta1">}}
// ```yaml
// apiVersion: networking.istio.io/v1beta1
// kind: ServiceEntry
// metadata:
//   name: external-svc-mongocluster
// spec:
//   hosts:
//   - mymongodb.somedomain # not used
//   addresses:
//   - 192.192.192.192/24 # VIPs
//   ports:
//   - number: 27018
//     name: mongodb
//     protocol: MONGO
//   location: MESH_INTERNAL
//   resolution: STATIC
//   endpoints:
//   - address: 2.2.2.2
//   - address: 3.3.3.3
// ```
// {{</tab>}}
// {{</tabset>}}
//
// and the associated DestinationRule
//
// {{<tabset category-name="example">}}
// {{<tab name="v1alpha3" category-value="v1alpha3">}}
// ```yaml
// apiVersion: networking.istio.io/v1alpha3
// kind: DestinationRule
// metadata:
//   name: mtls-mongocluster
// spec:
//   host: mymongodb.somedomain
//   trafficPolicy:
//     tls:
//       mode: MUTUAL
//       clientCertificate: /etc/certs/myclientcert.pem
//       privateKey: /etc/certs/client_private_key.pem
//       caCertificates: /etc/certs/rootcacerts.pem
// ```
// {{</tab>}}
//
// {{<tab name="v1beta1" category-value="v1beta1">}}
// ```yaml
// apiVersion: networking.istio.io/v1beta1
// kind: DestinationRule
// metadata:
//   name: mtls-mongocluster
// spec:
//   host: mymongodb.somedomain
//   trafficPolicy:
//     tls:
//       mode: MUTUAL
//       clientCertificate: /etc/certs/myclientcert.pem
//       privateKey: /etc/certs/client_private_key.pem
//       caCertificates: /etc/certs/rootcacerts.pem
// ```
// {{</tab>}}
// {{</tabset>}}
//
// The following example uses a combination of service entry and TLS
// routing in a virtual service to steer traffic based on the SNI value to
// an internal egress firewall.
//
// {{<tabset category-name="example">}}
// {{<tab name="v1alpha3" category-value="v1alpha3">}}
// ```yaml
// apiVersion: networking.istio.io/v1alpha3
// kind: ServiceEntry
// metadata:
//   name: external-svc-redirect
// spec:
//   hosts:
//   - wikipedia.org
//   - "*.wikipedia.org"
//   location: MESH_EXTERNAL
//   ports:
//   - number: 443
//     name: https
//     protocol: TLS
//   resolution: NONE
// ```
// {{</tab>}}
//
// {{<tab name="v1beta1" category-value="v1beta1">}}
// ```yaml
// apiVersion: networking.istio.io/v1beta1
// kind: ServiceEntry
// metadata:
//   name: external-svc-redirect
// spec:
//   hosts:
//   - wikipedia.org
//   - "*.wikipedia.org"
//   location: MESH_EXTERNAL
//   ports:
//   - number: 443
//     name: https
//     protocol: TLS
//   resolution: NONE
// ```
// {{</tab>}}
// {{</tabset>}}
//
// And the associated VirtualService to route based on the SNI value.
//
// {{<tabset category-name="example">}}
// {{<tab name="v1alpha3" category-value="v1alpha3">}}
// ```yaml
// apiVersion: networking.istio.io/v1alpha3
// kind: VirtualService
// metadata:
//   name: tls-routing
// spec:
//   hosts:
//   - wikipedia.org
//   - "*.wikipedia.org"
//   tls:
//   - match:
//     - sniHosts:
//       - wikipedia.org
//       - "*.wikipedia.org"
//     route:
//     - destination:
//         host: internal-egress-firewall.ns1.svc.cluster.local
// ```
// {{</tab>}}
//
// {{<tab name="v1beta1" category-value="v1beta1">}}
// ```yaml
// apiVersion: networking.istio.io/v1beta1
// kind: VirtualService
// metadata:
//   name: tls-routing
// spec:
//   hosts:
//   - wikipedia.org
//   - "*.wikipedia.org"
//   tls:
//   - match:
//     - sniHosts:
//       - wikipedia.org
//       - "*.wikipedia.org"
//     route:
//     - destination:
//         host: internal-egress-firewall.ns1.svc.cluster.local
// ```
// {{</tab>}}
// {{</tabset>}}
//
// The virtual service with TLS match serves to override the default SNI
// match. In the absence of a virtual service, traffic will be forwarded to
// the wikipedia domains.
//
// The following example demonstrates the use of a dedicated egress gateway
// through which all external service traffic is forwarded.
// The 'exportTo' field allows for control over the visibility of a service
// declaration to other namespaces in the mesh. By default, a service is exported
// to all namespaces. The following example restricts the visibility to the
// current namespace, represented by ".", so that it cannot be used by other
// namespaces.
//
// {{<tabset category-name="example">}}
// {{<tab name="v1alpha3" category-value="v1alpha3">}}
// ```yaml
// apiVersion: networking.istio.io/v1alpha3
// kind: ServiceEntry
// metadata:
//   name: external-svc-httpbin
//   namespace : egress
// spec:
//   hosts:
//   - httpbin.com
//   exportTo:
//   - "."
//   location: MESH_EXTERNAL
//   ports:
//   - number: 80
//     name: http
//     protocol: HTTP
//   resolution: DNS
// ```
// {{</tab>}}
//
// {{<tab name="v1beta1" category-value="v1beta1">}}
// ```yaml
// apiVersion: networking.istio.io/v1beta1
// kind: ServiceEntry
// metadata:
//   name: external-svc-httpbin
//   namespace : egress
// spec:
//   hosts:
//   - httpbin.com
//   exportTo:
//   - "."
//   location: MESH_EXTERNAL
//   ports:
//   - number: 80
//     name: http
//     protocol: HTTP
//   resolution: DNS
// ```
// {{</tab>}}
// {{</tabset>}}
//
// Define a gateway to handle all egress traffic.
//
// {{<tabset category-name="example">}}
// {{<tab name="v1alpha3" category-value="v1alpha3">}}
// ```yaml
// apiVersion: networking.istio.io/v1alpha3
// kind: Gateway
// metadata:
//  name: istio-egressgateway
//  namespace: istio-system
// spec:
//  selector:
//    istio: egressgateway
//  servers:
//  - port:
//      number: 80
//      name: http
//      protocol: HTTP
//    hosts:
//    - "*"
// ```
// {{</tab>}}
//
// {{<tab name="v1beta1" category-value="v1beta1">}}
// ```yaml
// apiVersion: networking.istio.io/v1beta1
// kind: Gateway
// metadata:
//  name: istio-egressgateway
//  namespace: istio-system
// spec:
//  selector:
//    istio: egressgateway
//  servers:
//  - port:
//      number: 80
//      name: http
//      protocol: HTTP
//    hosts:
//    - "*"
// ```
// {{</tab>}}
// {{</tabset>}}
//
// And the associated `VirtualService` to route from the sidecar to the
// gateway service (`istio-egressgateway.istio-system.svc.cluster.local`), as
// well as route from the gateway to the external service. Note that the
// virtual service is exported to all namespaces enabling them to route traffic
// through the gateway to the external service. Forcing traffic to go through
// a managed middle proxy like this is a common practice.
//
// {{<tabset category-name="example">}}
// {{<tab name="v1alpha3" category-value="v1alpha3">}}
// ```yaml
// apiVersion: networking.istio.io/v1alpha3
// kind: VirtualService
// metadata:
//   name: gateway-routing
//   namespace: egress
// spec:
//   hosts:
//   - httpbin.com
//   exportTo:
//   - "*"
//   gateways:
//   - mesh
//   - istio-egressgateway
//   http:
//   - match:
//     - port: 80
//       gateways:
//       - mesh
//     route:
//     - destination:
//         host: istio-egressgateway.istio-system.svc.cluster.local
//   - match:
//     - port: 80
//       gateways:
//       - istio-egressgateway
//     route:
//     - destination:
//         host: httpbin.com
// ```
// {{</tab>}}
//
// {{<tab name="v1beta1" category-value="v1beta1">}}
// ```yaml
// apiVersion: networking.istio.io/v1beta1
// kind: VirtualService
// metadata:
//   name: gateway-routing
//   namespace: egress
// spec:
//   hosts:
//   - httpbin.com
//   exportTo:
//   - "*"
//   gateways:
//   - mesh
//   - istio-egressgateway
//   http:
//   - match:
//     - port: 80
//       gateways:
//       - mesh
//     route:
//     - destination:
//         host: istio-egressgateway.istio-system.svc.cluster.local
//   - match:
//     - port: 80
//       gateways:
//       - istio-egressgateway
//     route:
//     - destination:
//         host: httpbin.com
// ```
// {{</tab>}}
// {{</tabset>}}
//
// The following example demonstrates the use of wildcards in the hosts for
// external services. If the connection has to be routed to the IP address
// requested by the application (i.e. application resolves DNS and attempts
// to connect to a specific IP), the discovery mode must be set to `NONE`.
//
// {{<tabset category-name="example">}}
// {{<tab name="v1alpha3" category-value="v1alpha3">}}
// ```yaml
// apiVersion: networking.istio.io/v1alpha3
// kind: ServiceEntry
// metadata:
//   name: external-svc-wildcard-example
// spec:
//   hosts:
//   - "*.bar.com"
//   location: MESH_EXTERNAL
//   ports:
//   - number: 80
//     name: http
//     protocol: HTTP
//   resolution: NONE
// ```
// {{</tab>}}
//
// {{<tab name="v1beta1" category-value="v1beta1">}}
// ```yaml
// apiVersion: networking.istio.io/v1beta1
// kind: ServiceEntry
// metadata:
//   name: external-svc-wildcard-example
// spec:
//   hosts:
//   - "*.bar.com"
//   location: MESH_EXTERNAL
//   ports:
//   - number: 80
//     name: http
//     protocol: HTTP
//   resolution: NONE
// ```
// {{</tab>}}
// {{</tabset>}}
//
// The following example demonstrates a service that is available via a
// Unix Domain Socket on the host of the client. The resolution must be
// set to STATIC to use Unix address endpoints.
//
// {{<tabset category-name="example">}}
// {{<tab name="v1alpha3" category-value="v1alpha3">}}
// ```yaml
// apiVersion: networking.istio.io/v1alpha3
// kind: ServiceEntry
// metadata:
//   name: unix-domain-socket-example
// spec:
//   hosts:
//   - "example.unix.local"
//   location: MESH_EXTERNAL
//   ports:
//   - number: 80
//     name: http
//     protocol: HTTP
//   resolution: STATIC
//   endpoints:
//   - address: unix:///var/run/example/socket
// ```
// {{</tab>}}
//
// {{<tab name="v1beta1" category-value="v1beta1">}}
// ```yaml
// apiVersion: networking.istio.io/v1beta1
// kind: ServiceEntry
// metadata:
//   name: unix-domain-socket-example
// spec:
//   hosts:
//   - "example.unix.local"
//   location: MESH_EXTERNAL
//   ports:
//   - number: 80
//     name: http
//     protocol: HTTP
//   resolution: STATIC
//   endpoints:
//   - address: unix:///var/run/example/socket
// ```
// {{</tab>}}
// {{</tabset>}}
//
// For HTTP-based services, it is possible to create a `VirtualService`
// backed by multiple DNS addressable endpoints. In such a scenario, the
// application can use the `HTTP_PROXY` environment variable to transparently
// reroute API calls for the `VirtualService` to a chosen backend. For
// example, the following configuration creates a non-existent external
// service called foo.bar.com backed by three domains: us.foo.bar.com:8080,
// uk.foo.bar.com:9080, and in.foo.bar.com:7080
//
// {{<tabset category-name="example">}}
// {{<tab name="v1alpha3" category-value="v1alpha3">}}
// ```yaml
// apiVersion: networking.istio.io/v1alpha3
// kind: ServiceEntry
// metadata:
//   name: external-svc-dns
// spec:
//   hosts:
//   - foo.bar.com
//   location: MESH_EXTERNAL
//   ports:
//   - number: 80
//     name: http
//     protocol: HTTP
//   resolution: DNS
//   endpoints:
//   - address: us.foo.bar.com
//     ports:
//       http: 8080
//   - address: uk.foo.bar.com
//     ports:
//       http: 9080
//   - address: in.foo.bar.com
//     ports:
//       http: 7080
// ```
// {{</tab>}}
//
// {{<tab name="v1beta1" category-value="v1beta1">}}
// ```yaml
// apiVersion: networking.istio.io/v1beta1
// kind: ServiceEntry
// metadata:
//   name: external-svc-dns
// spec:
//   hosts:
//   - foo.bar.com
//   location: MESH_EXTERNAL
//   ports:
//   - number: 80
//     name: http
//     protocol: HTTP
//   resolution: DNS
//   endpoints:
//   - address: us.foo.bar.com
//     ports:
//       http: 8080
//   - address: uk.foo.bar.com
//     ports:
//       http: 9080
//   - address: in.foo.bar.com
//     ports:
//       http: 7080
// ```
// {{</tab>}}
// {{</tabset>}}
//
// With `HTTP_PROXY=http://localhost/`, calls from the application to
// `http://foo.bar.com` will be load balanced across the three domains
// specified above. In other words, a call to `http://foo.bar.com/baz` would
// be translated to `http://uk.foo.bar.com/baz`.
//
// The following example illustrates the usage of a `ServiceEntry`
// containing a subject alternate name
// whose format conforms to the [SPIFFE standard](https://github.com/spiffe/spiffe/blob/master/standards/SPIFFE-ID.md):
//
// {{<tabset category-name="example">}}
// {{<tab name="v1alpha3" category-value="v1alpha3">}}
// ```yaml
// apiVersion: networking.istio.io/v1alpha3
// kind: ServiceEntry
// metadata:
//   name: httpbin
//   namespace : httpbin-ns
// spec:
//   hosts:
//   - httpbin.com
//   location: MESH_INTERNAL
//   ports:
//   - number: 80
//     name: http
//     protocol: HTTP
//   resolution: STATIC
//   endpoints:
//   - address: 2.2.2.2
//   - address: 3.3.3.3
//   subjectAltNames:
//   - "spiffe://cluster.local/ns/httpbin-ns/sa/httpbin-service-account"
// ```
// {{</tab>}}
//
// {{<tab name="v1beta1" category-value="v1beta1">}}
// ```yaml
// apiVersion: networking.istio.io/v1beta1
// kind: ServiceEntry
// metadata:
//   name: httpbin
//   namespace : httpbin-ns
// spec:
//   hosts:
//   - httpbin.com
//   location: MESH_INTERNAL
//   ports:
//   - number: 80
//     name: http
//     protocol: HTTP
//   resolution: STATIC
//   endpoints:
//   - address: 2.2.2.2
//   - address: 3.3.3.3
//   subjectAltNames:
//   - "spiffe://cluster.local/ns/httpbin-ns/sa/httpbin-service-account"
// ```
// {{</tab>}}
// {{</tabset>}}
//
// The following example demonstrates the use of `ServiceEntry` with a
// `workloadSelector` to handle the migration of a service
// `details.bookinfo.com` from VMs to Kubernetes. The service has two
// VM-based instances with sidecars as well as a set of Kubernetes
// pods managed by a standard deployment object. Consumers of this
// service in the mesh will be automatically load balanced across the
// VMs and Kubernetes.  VM for the `details.bookinfo.com`
// service. This VM has sidecar installed and bootstrapped using the
// `details-legacy` service account. The sidecar receives HTTP traffic
// on port 80 (wrapped in istio mutual TLS) and forwards it to the
// application on the localhost on the same port.
//
// {{<tabset category-name="example">}}
// {{<tab name="v1alpha3" category-value="v1alpha3">}}
// ```yaml
// apiVersion: networking.istio.io/v1alpha3
// kind: WorkloadEntry
// metadata:
//   name: details-vm-1
// spec:
//   serviceAccount: details
//   address: 2.2.2.2
//   labels:
//     app: details
//     instance-id: vm1
// ---
// apiVersion: networking.istio.io/v1alpha3
// kind: WorkloadEntry
// metadata:
//   name: details-vm-2
// spec:
//   serviceAccount: details
//   address: 3.3.3.3
//   labels:
//     app: details
//     instance-id: vm2
// ```
// {{</tab>}}
//
// {{<tab name="v1beta1" category-value="v1beta1">}}
// ```yaml
// apiVersion: networking.istio.io/v1beta1
// kind: WorkloadEntry
// metadata:
//   name: details-vm-1
// spec:
//   serviceAccount: details
//   address: 2.2.2.2
//   labels:
//     app: details
//     instance-id: vm1
// ---
// apiVersion: networking.istio.io/v1beta1
// kind: WorkloadEntry
// metadata:
//   name: details-vm-2
// spec:
//   serviceAccount: details
//   address: 3.3.3.3
//   labels:
//     app: details
//     instance-id: vm2
// ```
// {{</tab>}}
// {{</tabset>}}
//
// Assuming there is also a Kubernetes deployment with pod labels
// `app: details` using the same service account `details`, the
// following service entry declares a service spanning both VMs and
// Kubernetes:
//
// {{<tabset category-name="example">}}
// {{<tab name="v1alpha3" category-value="v1alpha3">}}
// ```yaml
// apiVersion: networking.istio.io/v1alpha3
// kind: ServiceEntry
// metadata:
//   name: details-svc
// spec:
//   hosts:
//   - details.bookinfo.com
//   location: MESH_INTERNAL
//   ports:
//   - number: 80
//     name: http
//     protocol: HTTP
//   resolution: STATIC
//   workloadSelector:
//     labels:
//       app: details
// ```
// {{</tab>}}
//
// {{<tab name="v1beta1" category-value="v1beta1">}}
// ```yaml
// apiVersion: networking.istio.io/v1beta1
// kind: ServiceEntry
// metadata:
//   name: details-svc
// spec:
//   hosts:
//   - details.bookinfo.com
//   location: MESH_INTERNAL
//   ports:
//   - number: 80
//     name: http
//     protocol: HTTP
//   resolution: STATIC
//   workloadSelector:
//     labels:
//       app: details
// ```
// {{</tab>}}
// {{</tabset>}}
package istio.networking.v1beta1;

option go_package = "istio.io/api/networking/v1beta1";

// ServiceEntry enables adding additional entries into Istio's internal
// service registry.
//
// <!-- crd generation tags
// +cue-gen:ServiceEntry:groupName:networking.istio.io
// +cue-gen:ServiceEntry:version:v1beta1
// +cue-gen:ServiceEntry:annotations:helm.sh/resource-policy=keep
// +cue-gen:ServiceEntry:labels:app=istio-pilot,chart=istio,heritage=Tiller,release=istio
// +cue-gen:ServiceEntry:subresource:status
// +cue-gen:ServiceEntry:scope:Namespaced
// +cue-gen:ServiceEntry:resource:categories=istio-io,networking-istio-io,shortNames=se,plural=serviceentries
// +cue-gen:ServiceEntry:printerColumn:name=Hosts,type=string,JSONPath=.spec.hosts,description="The hosts associated with the ServiceEntry"
// +cue-gen:ServiceEntry:printerColumn:name=Location,type=string,JSONPath=.spec.location,description="Whether the service is external to the
// mesh or part of the mesh (MESH_EXTERNAL or MESH_INTERNAL)"
// +cue-gen:ServiceEntry:printerColumn:name=Resolution,type=string,JSONPath=.spec.resolution,description="Service discovery mode for the hosts
// (NONE, STATIC, or DNS)"
// +cue-gen:ServiceEntry:printerColumn:name=Age,type=date,JSONPath=.metadata.creationTimestamp,description="CreationTimestamp is a timestamp
// representing the server time when this object was created. It is not guaranteed to be set in happens-before order across separate operations.
// Clients may not set this value. It is represented in RFC3339 form and is in UTC.
// Populated by the system. Read-only. Null for lists. More info: https://git.k8s.io/community/contributors/devel/api-conventions.md#metadata"
// +cue-gen:ServiceEntry:preserveUnknownFields:false
// -->
//
// <!-- go code generation tags
// +kubetype-gen
// +kubetype-gen:groupVersion=networking.istio.io/v1beta1
// +genclient
// +k8s:deepcopy-gen=true
// -->
message ServiceEntry {
  // The hosts associated with the ServiceEntry. Could be a DNS
  // name with wildcard prefix.
  //
  // 1. The hosts field is used to select matching hosts in VirtualServices and DestinationRules.
  // 2. For HTTP traffic the HTTP Host/Authority header will be matched against the hosts field.
  // 3. For HTTPs or TLS traffic containing Server Name Indication (SNI), the SNI value
  // will be matched against the hosts field.
  //
  // **NOTE 1:** When resolution is set to type DNS and no endpoints
  // are specified, the host field will be used as the DNS name of the
  // endpoint to route traffic to.
  //
  // **NOTE 2:** If the hostname matches with the name of a service
  // from another service registry such as Kubernetes that also
  // supplies its own set of endpoints, the ServiceEntry will be
  // treated as a decorator of the existing Kubernetes
  // service. Properties in the service entry will be added to the
  // Kubernetes service if applicable. Currently, the only the
  // following additional properties will be considered by `istiod`:
  //
  // 1. subjectAltNames: In addition to verifying the SANs of the
  //    service accounts associated with the pods of the service, the
  //    SANs specified here will also be verified.
  //
  repeated string hosts = 1 [(google.api.field_behavior) = REQUIRED];

  // The virtual IP addresses associated with the service. Could be CIDR
  // prefix. For HTTP traffic, generated route configurations will include http route
  // domains for both the `addresses` and `hosts` field values and the destination will
  // be identified based on the HTTP Host/Authority header.
  // If one or more IP addresses are specified,
  // the incoming traffic will be identified as belonging to this service
  // if the destination IP matches the IP/CIDRs specified in the addresses
  // field. If the Addresses field is empty, traffic will be identified
  // solely based on the destination port. In such scenarios, the port on
  // which the service is being accessed must not be shared by any other
  // service in the mesh. In other words, the sidecar will behave as a
  // simple TCP proxy, forwarding incoming traffic on a specified port to
  // the specified destination endpoint IP/host. Unix domain socket
  // addresses are not supported in this field.
  repeated string addresses = 2;

  // The ports associated with the external service. If the
  // Endpoints are Unix domain socket addresses, there must be exactly one
  // port.
  repeated Port ports = 3 [(google.api.field_behavior) = REQUIRED];

  // Location specifies whether the service is part of Istio mesh or
  // outside the mesh.  Location determines the behavior of several
  // features, such as service-to-service mTLS authentication, policy
  // enforcement, etc. When communicating with services outside the mesh,
  // Istio's mTLS authentication is disabled, and policy enforcement is
  // performed on the client-side as opposed to server-side.
  enum Location {
    // Signifies that the service is external to the mesh. Typically used
    // to indicate external services consumed through APIs.
    MESH_EXTERNAL = 0;

    // Signifies that the service is part of the mesh. Typically used to
    // indicate services added explicitly as part of expanding the service
    // mesh to include unmanaged infrastructure (e.g., VMs added to a
    // Kubernetes based service mesh).
    MESH_INTERNAL = 1;
  };

  // Specify whether the service should be considered external to the mesh
  // or part of the mesh.
  Location location = 4;

  // Resolution determines how the proxy will resolve the IP addresses of
  // the network endpoints associated with the service, so that it can
  // route to one of them. The resolution mode specified here has no impact
  // on how the application resolves the IP address associated with the
  // service. The application may still have to use DNS to resolve the
  // service to an IP so that the outbound traffic can be captured by the
  // Proxy. Alternatively, for HTTP services, the application could
  // directly communicate with the proxy (e.g., by setting HTTP_PROXY) to
  // talk to these services.
  enum Resolution {
    // Assume that incoming connections have already been resolved (to a
    // specific destination IP address). Such connections are typically
    // routed via the proxy using mechanisms such as IP table REDIRECT/
    // eBPF. After performing any routing related transformations, the
    // proxy will forward the connection to the IP address to which the
    // connection was bound.
    NONE = 0;

    // Use the static IP addresses specified in endpoints (see below) as the
    // backing instances associated with the service.
    STATIC = 1;

    // Attempt to resolve the IP address by querying the ambient DNS,
    // during request processing. If no endpoints are specified, the proxy
    // will resolve the DNS address specified in the hosts field, if
    // wildcards are not used. If endpoints are specified, the DNS
    // addresses specified in the endpoints will be resolved to determine
    // the destination IP address.  DNS resolution cannot be used with Unix
    // domain socket endpoints.
    DNS = 2;
  };

  // Service discovery mode for the hosts. Care must be taken
  // when setting the resolution mode to NONE for a TCP port without
  // accompanying IP addresses. In such cases, traffic to any IP on
  // said port will be allowed (i.e. `0.0.0.0:<port>`).
  Resolution resolution = 5 [(google.api.field_behavior) = REQUIRED];

  // One or more endpoints associated with the service. Only one of
  // `endpoints` or `workloadSelector` can be specified.
  repeated WorkloadEntry endpoints = 6;

  // Applicable only for MESH_INTERNAL services. Only one of
  // `endpoints` or `workloadSelector` can be specified. Selects one
  // or more Kubernetes pods or VM workloads (specified using
  // `WorkloadEntry`) based on their labels. The `WorkloadEntry` object
  // representing the VMs should be defined in the same namespace as
  // the ServiceEntry.
  WorkloadSelector workload_selector = 9;

  // A list of namespaces to which this service is exported. Exporting a service
  // allows it to be used by sidecars, gateways and virtual services defined in
  // other namespaces. This feature provides a mechanism for service owners
  // and mesh administrators to control the visibility of services across
  // namespace boundaries.
  //
  // If no namespaces are specified then the service is exported to all
  // namespaces by default.
  //
  // The value "." is reserved and defines an export to the same namespace that
  // the service is declared in. Similarly the value "*" is reserved and
  // defines an export to all namespaces.
  //
  // For a Kubernetes Service, the equivalent effect can be achieved by setting
  // the annotation "networking.istio.io/exportTo" to a comma-separated list
  // of namespace names.
  //
  // NOTE: in the current release, the `exportTo` value is restricted to
  // "." or "*" (i.e., the current namespace or all namespaces).
  repeated string export_to = 7;

  // If specified, the proxy will verify that the server certificate's
  // subject alternate name matches one of the specified values.
  //
  // NOTE: When using the workloadEntry with workloadSelectors, the
  // service account specified in the workloadEntry will also be used
  // to derive the additional subject alternate names that should be
  // verified.
  repeated string subject_alt_names = 8;
}