syntax = "proto3";

package yandex.cloud.apploadbalancer.v1;

import "google/protobuf/duration.proto";
import "yandex/cloud/apploadbalancer/v1/payload.proto";
import "yandex/cloud/validation.proto";

option go_package = "github.com/yandex-cloud/go-genproto/yandex/cloud/apploadbalancer/v1;apploadbalancer";
option java_package = "yandex.cloud.api.apploadbalancer.v1";

// A virtual host resource.
// For details about the concept, see [documentation](/docs/application-load-balancer/concepts/http-router#virtual-host).
message VirtualHost {
  // Name of the virtual host. The name is unique within the HTTP router.
  string name = 1 [(required) = true];

  // List of domains that are attributed to the virtual host.
  //
  // The host is selected to process the request received by the load balancer
  // if the domain specified in the HTTP/1.1 `Host` header or the HTTP/2 `:authority` pseudo-header matches a domain
  // specified in the host.
  //
  // A wildcard asterisk character (`*`) matches 0 or more characters.
  //
  // If not specified, all domains are attributed to the host, which is the same as specifying a `*` value.
  // An HTTP router must not contain more than one virtual host to which all domains are attributed.
  repeated string authority = 2;

  // Routes of the virtual host.
  //
  // A route contains a set of conditions (predicates) that are used by the load balancer to select the route
  // for the request and an action on the request.
  // For details about the concept, see [documentation](/docs/application-load-balancer/concepts/http-router#routes).
  //
  // The order of routes matters: the first route whose predicate matches the request is selected.
  // The most specific routes should be at the top of the list, so that they are not overridden.
  // For example, if the first HTTP route is configured, via [HttpRoute.match], to match paths prefixed with just `/`,
  // other routes are never matched.
  repeated Route routes = 3;

  // Deprecated, use route_options.modify_request_headers.
  repeated HeaderModification modify_request_headers = 4;

  // Deprecated, use route_options.modify_response_headers.
  repeated HeaderModification modify_response_headers = 5;

  RouteOptions route_options = 6;
}

message RouteOptions {
  // Apply the following modifications to the request headers.
  repeated HeaderModification modify_request_headers = 1;

  // Apply the following modifications to the response headers.
  repeated HeaderModification modify_response_headers = 2;
}

// A header modification resource.
message HeaderModification {
  // Name of the header.
  string name = 1;

  // Operation to perform on the header.
  oneof operation {
    // Appends the specified string to the header value.
    //
    // Variables [defined for Envoy proxy](https://www.envoyproxy.io/docs/envoy/latest/configuration/http/http_conn_man/headers#custom-request-response-headers)
    // are supported.
    string append = 2;

    // Replaces the value of the header with the specified string.
    //
    // Variables [defined for Envoy proxy](https://www.envoyproxy.io/docs/envoy/latest/configuration/http/http_conn_man/headers#custom-request-response-headers)
    // are supported.
    string replace = 3;

    // Removes the header.
    bool remove = 4;

    // Replaces the name of the header with the specified string.
    // This operation is only supported for ALB Virtual Hosts.
    string rename = 5;
  }
}

// A route resource.
// For details about the concept, see [documentation](/docs/application-load-balancer/concepts/http-router#routes).
message Route {
  // Name of the route.
  string name = 1 [(required) = true];

  // Route configuration.
  oneof route {
    option (exactly_one) = true;
    // HTTP route configuration.
    HttpRoute http = 2;

    // gRPC route configuration.
    GrpcRoute grpc = 3;
  }
  RouteOptions route_options = 4;
}

// An HTTP route configuration resource.
message HttpRoute {
  // Condition (predicate) used to select the route.
  HttpRouteMatch match = 1;

  // Action performed on the request if the route is selected.
  oneof action {
    option (exactly_one) = true;

    // Forwards the request to a backend group for processing as configured.
    HttpRouteAction route = 2;

    // Redirects the request as configured.
    RedirectAction redirect = 3;

    // Instructs the load balancer to respond directly as configured.
    DirectResponseAction direct_response = 4;
  }
}

// A gRPC route configuration resource.
message GrpcRoute {
  // Condition (predicate) used to select the route.
  GrpcRouteMatch match = 1;

  // Action performed on the request if the route is selected.
  oneof action {
    option (exactly_one) = true;

    // Forwards the request to a backend group for processing as configured.
    GrpcRouteAction route = 2;

    // Instructs the load balancer to respond directly with a specified status.
    GrpcStatusResponseAction status_response = 3;
  }
}

// An HTTP route condition (predicate) resource.
message HttpRouteMatch {
  // HTTP method specified in the request.
  repeated string http_method = 1;

  // Match settings for the path specified in the request.
  //
  // If not specified, the route matches all paths.
  StringMatch path = 2;
}

// A gRPC route condition (predicate) resource.
message GrpcRouteMatch {
  // Match settings for gRPC service method called in the request.
  //
  // A match string must be a fully qualified method name, e.g. `foo.bar.v1.BazService/Get`, or a prefix of such.
  //
  // If not specified, the route matches all methods.
  StringMatch fqmn = 1;
}

// A string matcher resource.
message StringMatch {
  // Match string for either exact or prefix match.
  oneof match {
    option (exactly_one) = true;

    // Exact match string.
    string exact_match = 1;

    // Prefix match string.
    string prefix_match = 2;
  }
}

// A redirect action resource.
message RedirectAction {
  // URI scheme replacement.
  //
  // If `http` or `https` scheme is to be replaced and `80` or `443` port is specified in the original URI,
  // the port is also removed.
  //
  // If not specified, the original scheme and port are used.
  string replace_scheme = 1;

  // URI host replacement.
  //
  // If not specified, the original host is used.
  string replace_host = 2;

  // URI host replacement.
  //
  // If not specified, the original host is used.
  int64 replace_port = 3;

  // URI path replacement.
  //
  // If not specified, the original path is used.
  oneof path {
    // Replacement for the whole path.
    string replace_path = 4;

    // Replacement for the path prefix matched by [StringMatch].
    //
    // For instance, if [StringMatch.prefix_match] value is `/foo` and `replace_prefix` value is `/bar`,
    // a request with `https://example.com/foobaz` URI is redirected to `https://example.com/barbaz`.
    // For [StringMatch.exact_match], the whole path is replaced.
    string replace_prefix = 5;
  }

  // Removes URI query.
  bool remove_query = 6;

  // HTTP status codes supported for use in redirect responses.
  enum RedirectResponseCode {

    // `301 Moved Permanently` status code.
    MOVED_PERMANENTLY = 0;

    // `302 Found` status code.
    FOUND = 1;

    // `303 See Other` status code.
    SEE_OTHER = 2;

    // `307 Temporary Redirect` status code.
    TEMPORARY_REDIRECT = 3;

    // `308 Permanent Redirect` status code.
    PERMANENT_REDIRECT = 4;
  }

  // HTTP status code to use in redirect responses.
  RedirectResponseCode response_code = 7;
}

// A direct response action resource.
message DirectResponseAction {
  // HTTP status code to use in responses.
  int64 status = 1 [(value) = "100-599"];

  // Response body.
  Payload body = 2;
}

// A gRPC status response action resource.
message GrpcStatusResponseAction {
  // gRPC status code supported for use in responses.
  enum Status {

    // `OK` (0) status code.
    OK = 0;

    // `INVALID_ARGUMENT` (3) status code.
    INVALID_ARGUMENT = 1;

    // `NOT_FOUND` (5) status code.
    NOT_FOUND = 2;

    // `PERMISSION_DENIED` (7) status code.
    PERMISSION_DENIED = 3;

    // `UNAUTHENTICATED` (16) status code.
    UNAUTHENTICATED = 4;

    // `UNIMPLEMENTED` (12) status code.
    UNIMPLEMENTED = 5;

    // `INTERNAL` (13) status code.
    INTERNAL = 6;

    // `UNAVAILABLE` (14) status code.
    UNAVAILABLE = 7;
  }

  // gRPC [status code](https://grpc.github.io/grpc/core/md_doc_statuscodes.html) to use in responses.
  Status status = 1;
}

// An HTTP route action resource.
message HttpRouteAction {
  // Backend group to forward requests to.
  string backend_group_id = 1 [(required) = true];

  // Overall timeout for an HTTP connection between a load balancer node an a backend from the backend group:
  // the maximum time the connection is kept alive for, regardless of whether data is transferred over it.
  //
  // If a connection times out, the load balancer responds to the client with a `504 Gateway Timeout` status code.
  //
  // Default value: `60`.
  google.protobuf.Duration timeout = 2;

  // Idle timeout for an HTTP connection between a load balancer node an a backend from the backend group:
  // the maximum time the connection is allowed to be idle, i.e. without any data transferred over it.
  //
  // Specifying meaningful values for both [timeout] and `idle_timeout` is useful for implementing
  // server-push mechanisms such as long polling, server-sent events (`EventSource` interface) etc.
  //
  // If a connection times out, the load balancer responds to the client with a `504 Gateway Timeout` status code.
  //
  // If not specified, no idle timeout is used, and an alive connection may be idle for any duration (see [timeout]).
  google.protobuf.Duration idle_timeout = 3;

  // Value rewrite settings for HTTP/1.1 `Host` headers and HTTP/2 `:authority` pseudo-headers.
  //
  // If not specified, the host is not changed.
  oneof host_rewrite_specifier {
    // Host replacement.
    string host_rewrite = 4;

    // Automatically replaces the host with that of the target.
    bool auto_host_rewrite = 5;
  }

  // Replacement for the path prefix matched by [StringMatch].
  //
  // For instance, if [StringMatch.prefix_match] value is `/foo` and `replace_prefix` value is `/bar`,
  // a request with `/foobaz` path is forwarded with `/barbaz` path.
  // For [StringMatch.exact_match], the whole path is replaced.
  //
  // If not specified, the path is not changed.
  string prefix_rewrite = 6;

  // Supported values for HTTP `Upgrade` header. E.g. `websocket`.
  repeated string upgrade_types = 7;
}

// A gRPC route action resource.
message GrpcRouteAction {
  // Backend group to forward requests to.
  string backend_group_id = 1 [(required) = true];

  // Overall timeout for an underlying HTTP connection between a load balancer node an a backend from the backend group:
  // the maximum time the connection is kept alive for, regardless of whether data is transferred over it.
  //
  // If a client specifies a lower timeout in HTTP `grpc-timeout` header, the `max_timeout` value is ignored.
  //
  // If a connection times out, the load balancer responds to the client with an `UNAVAILABLE` status code.
  //
  // Default value: `60`.
  google.protobuf.Duration max_timeout = 2;

  // Idle timeout for an underlying HTTP connection between a load balancer node an a backend from the backend group:
  // the maximum time the connection is allowed to be idle, i.e. without any data transferred over it.
  //
  // Specifying meaningful values for both [max_timeout] and `idle_timeout` is useful for implementing
  // server-push mechanisms such as long polling, server-sent events etc.
  //
  // If a connection times out, the load balancer responds to the client with an `UNAVAILABLE` status code.
  //
  // If not specified, no idle timeout is used, and an alive connection may be idle for any duration
  // (see [max_timeout]).
  google.protobuf.Duration idle_timeout = 3;

  // Value rewrite settings for HTTP/1.1 `Host` headers and HTTP/2 `:authority` pseudo-headers.
  //
  // If not specified, the host is not changed.
  oneof host_rewrite_specifier {
    // Host replacement.
    string host_rewrite = 4;

    // Automatically replaces the host with that of the target.
    bool auto_host_rewrite = 5;
  }
}