// 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/v1alpha3/workload_entry.proto";

// $schema: istio.networking.v1alpha3.WorkloadGroup
// $title: Workload Group
// $description: Describes a collection of workload instances.
// $location: https://istio.io/docs/reference/config/networking/workload-group.html
// $aliases: [/docs/reference/config/networking/v1alpha3/workload-group]

// `WorkloadGroup` describes a collection of workload instances.
// It provides a specification that the workload instances can use to bootstrap 
// their proxies, including the metadata and identity. It is only intended to 
// be used with non-k8s workloads like Virtual Machines, and is meant to mimic 
// the existing sidecar injection and deployment specification model used for 
// Kubernetes workloads to bootstrap Istio proxies.
//
// The following example declares a workload group representing a collection 
// of workloads that will be registered under `reviews` in namespace
// `bookinfo`. The set of labels will be associated with each workload 
// instance during the bootstrap process, and the ports 3550 and 8080
// will be associated with the workload group and use service account `default`.
// `app.kubernetes.io/version` is just an arbitrary example of a label.
//
// {{<tabset category-name="example">}}
// {{<tab name="v1alpha3" category-value="v1alpha3">}}
// ```yaml
// apiVersion: networking.istio.io/v1alpha3
// kind: WorkloadGroup
// metadata:
//   name: reviews
//   namespace: bookinfo
// spec:
//   metadata:
//     labels:
//       app.kubernetes.io/name: reviews
//       app.kubernetes.io/version: "1.3.4"
//   template:
//     ports:
//       grpc: 3550
//       http: 8080
//     serviceAccount: default
//   probe:
//     initialDelaySeconds: 5
//     timeoutSeconds: 3
//     periodSeconds: 4
//     successThreshold: 3
//     failureThreshold: 3
//     httpGet:
//      path: /foo/bar
//      host: 127.0.0.1
//      port: 3100
//      scheme: https
//      httpHeaders:
//      - name: Lit-Header
//        value: Im-The-Best
// ```
// {{</tab>}}
// {{</tabset>}}
//
package istio.networking.v1alpha3;

option go_package = "istio.io/api/networking/v1alpha3";

// `WorkloadGroup` enables specifying the properties of a single workload for bootstrap and
// provides a template for `WorkloadEntry`, similar to how `Deployment` specifies properties
// of workloads via `Pod` templates. A `WorkloadGroup` can have more than one `WorkloadEntry`.
// `WorkloadGroup` has no relationship to resources which control service registry like `ServiceEntry` 
// and as such doesn't configure host name for these workloads.
//
// <!-- crd generation tags
// +cue-gen:WorkloadGroup:groupName:networking.istio.io
// +cue-gen:WorkloadGroup:version:v1alpha3
// +cue-gen:WorkloadGroup:storageVersion
// +cue-gen:WorkloadGroup:subresource:status
// +cue-gen:WorkloadGroup:scope:Namespaced
// +cue-gen:WorkloadGroup:resource:categories=istio-io,networking-istio-io,shortNames=wg,plural=workloadgroups
// +cue-gen:WorkloadGroup: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:WorkloadGroup:preserveUnknownFields:false
// -->
//
// <!-- go code generation tags
// +kubetype-gen
// +kubetype-gen:groupVersion=networking.istio.io/v1alpha3
// +genclient
// +k8s:deepcopy-gen=true
// -->
message WorkloadGroup {
  // Metadata that will be used for all corresponding `WorkloadEntries`.
  // User labels for a workload group should be set here in `metadata` rather than in `template`.
  ObjectMeta metadata = 1;

  // Template to be used for the generation of `WorkloadEntry` resources that belong to this `WorkloadGroup`.
  // Please note that `address` and `labels` fields should not be set in the template, and an empty `serviceAccount`
  // should default to `default`. The workload identities (mTLS certificates) will be bootstrapped using the
  // specified service account's token. Workload entries in this group will be in the same namespace as the
  // workload group, and inherit the labels and annotations from the above `metadata` field.
  WorkloadEntry template = 2 [(google.api.field_behavior) = REQUIRED];

  // `ObjectMeta` describes metadata that will be attached to a `WorkloadEntry`.
  // It is a subset of the supported Kubernetes metadata.
  message ObjectMeta {
      // Labels to attach
      map<string, string> labels = 1;

      // Annotations to attach
      map<string, string> annotations = 2;
  }

  // `ReadinessProbe` describes the configuration the user must provide for healthchecking on their workload.
  // This configuration mirrors K8S in both syntax and logic for the most part.
  ReadinessProbe probe = 3;
}

message ReadinessProbe {

    // Number of seconds after the container has started before readiness probes are initiated.
    int32 initial_delay_seconds = 2;

    // Number of seconds after which the probe times out.
    // Defaults to 1 second. Minimum value is 1.
    int32 timeout_seconds = 3;

    // How often (in seconds) to perform the probe.
    // Default to 10 seconds. Minimum value is 1.
    int32 period_seconds = 4;

    // Minimum consecutive successes for the probe to be considered successful after having failed.
    // Defaults to 1.
    int32 success_threshold = 5;

    // Minimum consecutive failures for the probe to be considered failed after having succeeded.
    // Defaults to 3.
    int32 failure_threshold = 6;

    // Users can only provide one configuration for healthchecks (tcp, http, exec),
    // and this is expressed as a oneof. All of the other configuration values
    // hold true for any of the healthcheck methods.
    oneof health_check_method {
        // an http get is performed to a given endpoint
        // and the status/able to connect determines health.
        HTTPHealthCheckConfig http_get = 7;
        // health is determined by if the proxy is able to connect.
        TCPHealthCheckConfig tcp_socket = 8;
        // health is determined by how the command that is executed exited.
        ExecHealthCheckConfig exec = 9;
    }
}

message HTTPHealthCheckConfig {
    // Path to access on the HTTP server.
    string path = 1;

    // port on which the endpoint lives.
    uint32 port = 2;

    // Host name to connect to, defaults to the pod IP. You probably want to set
    // "Host" in httpHeaders instead.
    string host = 3;

    // http or https, defaults to http
    string scheme = 4;

    // headers the proxy will pass on to make the request.
    // allows repeated headers.
    repeated HTTPHeader http_headers = 5;
}

message HTTPHeader {
    // The header field name
    string name = 1;

    // The header field value
    string value = 2;
}

message TCPHealthCheckConfig {
    // host to connect to, defaults to localhost
    string host = 1;
    // port of host
    uint32 port = 2;
}

message ExecHealthCheckConfig {
    // command to run. Exit status of 0 is treated as live/healthy and non-zero is unhealthy.
    repeated string command = 1;
}

