FunctionRpc.proto

syntax = "proto3";
// protobuf vscode extension: https://marketplace.visualstudio.com/items?itemName=zxh404.vscode-proto3

option java_multiple_files = true;
option java_package = "com.microsoft.azure.functions.rpc.messages";
option java_outer_classname = "FunctionProto";
option csharp_namespace = "Microsoft.Azure.WebJobs.Script.Grpc.Messages";
option go_package ="github.com/Azure/azure-functions-go-worker/internal/rpc";

package AzureFunctionsRpcMessages;

import "google/protobuf/duration.proto";

// Interface exported by the server.
service FunctionRpc {
 rpc EventStream (stream StreamingMessage) returns (stream StreamingMessage) {}
}

message StreamingMessage {
  // Used to identify message between host and worker
  string request_id = 1;

  // Payload of the message
  oneof content {

    // Worker initiates stream
    StartStream start_stream = 20; 

    // Host sends capabilities/init data to worker
    WorkerInitRequest worker_init_request = 17;
    // Worker responds after initializing with its capabilities & status
    WorkerInitResponse worker_init_response = 16;

    // Worker periodically sends empty heartbeat message to host
    WorkerHeartbeat worker_heartbeat = 15;

    // Host sends terminate message to worker.
    // Worker terminates if it can, otherwise host terminates after a grace period
    WorkerTerminate worker_terminate = 14;

    // Add any worker relevant status to response
    WorkerStatusRequest worker_status_request = 12;
    WorkerStatusResponse worker_status_response = 13;

    // On file change event, host sends notification to worker
    FileChangeEventRequest file_change_event_request = 6;

    // Worker requests a desired action (restart worker, reload function)
    WorkerActionResponse worker_action_response = 7;
    
    // Host sends required metadata to worker to load function
    FunctionLoadRequest function_load_request = 8;
    // Worker responds after loading with the load result
    FunctionLoadResponse function_load_response = 9;
    
    // Host requests a given invocation
    InvocationRequest invocation_request = 4;

    // Worker responds to a given invocation
    InvocationResponse invocation_response = 5;

    // Host sends cancel message to attempt to cancel an invocation. 
    // If an invocation is cancelled, host will receive an invocation response with status cancelled.
    InvocationCancel invocation_cancel = 21;

    // Worker logs a message back to the host
    RpcLog rpc_log = 2;

    FunctionEnvironmentReloadRequest function_environment_reload_request = 25;

    FunctionEnvironmentReloadResponse function_environment_reload_response = 26;
  }
}

// Process.Start required info
//   connection details
//   protocol type
//   protocol version 

// Worker sends the host information identifying itself
message StartStream {
  // id of the worker
  string worker_id = 2;
}

// Host requests the worker to initialize itself 
message WorkerInitRequest {
  // version of the host sending init request
  string host_version = 1;

  // A map of host supported features/capabilities
  map<string, string> capabilities = 2;

  // inform worker of supported categories and their levels
  // i.e. Worker = Verbose, Function.MyFunc = None
  map<string, RpcLog.Level> log_categories = 3;
}

// Worker responds with the result of initializing itself
message WorkerInitResponse {
  // Version of worker
  string worker_version = 1;
  // A map of worker supported features/capabilities
  map<string, string> capabilities = 2;

  // Status of the response
  StatusResult result = 3;
}

// Used by the host to determine success/failure/cancellation
message StatusResult {
  // Indicates Failure/Success/Cancelled
  enum Status {
    Failure = 0;
    Success = 1;
    Cancelled = 2;
  }
  // Status for the given result
  Status status = 4;

  // Specific message about the result
  string result = 1;

  // Exception message (if exists) for the status
  RpcException exception = 2;

  // Captured logs or relevant details can use the logs property
  repeated RpcLog logs = 3;
}

// TODO: investigate grpc heartbeat - don't limit to grpc implemention

// Message is empty by design - Will add more fields in future if needed
message WorkerHeartbeat {}

// Warning before killing the process after grace_period
// Worker self terminates ..no response on this
message WorkerTerminate {
  google.protobuf.Duration grace_period = 1;
}

// Host notifies worker of file content change
message FileChangeEventRequest {
  // Types of File change operations (See link for more info: https://msdn.microsoft.com/en-us/library/t6xf43e0(v=vs.110).aspx)
  enum Type {
	  Unknown = 0;
    Created = 1;
    Deleted = 2;
    Changed = 4;
    Renamed = 8;
    All = 15;
  }

  // type for this event
  Type type = 1;

  // full file path for the file change notification
  string full_path = 2;

  // Name of the function affected
  string name = 3;
}

// Indicates whether worker reloaded successfully or needs a restart
message WorkerActionResponse {
  // indicates whether a restart is needed, or reload succesfully
  enum Action {
    Restart = 0;
    Reload = 1;
  }
  
  // action for this response
  Action action = 1;

  // text reason for the response
  string reason = 2;
}

// NOT USED
message WorkerStatusRequest{
}

// NOT USED
message WorkerStatusResponse {
}

message FunctionEnvironmentReloadRequest {
  // Environment variables from the current process
  map<string, string> environment_variables = 1;
}

message FunctionEnvironmentReloadResponse {
  // Status of the response
  StatusResult result = 3;
}

// Host tells the worker to load a Function
message FunctionLoadRequest {
  // unique function identifier (avoid name collisions, facilitate reload case)
  string function_id = 1;

  // Metadata for the request
  RpcFunctionMetadata metadata = 2;
}

// Worker tells host result of reload
message FunctionLoadResponse {
  // unique function identifier
  string function_id = 1;

  // Result of load operation
  StatusResult result = 2;
  // TODO: return type expected?
}

// Information on how a Function should be loaded and its bindings
message RpcFunctionMetadata {
  // TODO: do we want the host's name - the language worker might do a better job of assignment than the host
  string name = 4;

  // base directory for the Function
  string directory = 1;
  
  // Script file specified
  string script_file = 2;

  // Entry point specified
  string entry_point = 3;

  // Bindings info
  map<string, BindingInfo> bindings = 6;
}

// Host requests worker to invoke a Function
message InvocationRequest {
  // Unique id for each invocation
  string invocation_id = 1;

  // Unique id for each Function
  string function_id = 2;

  // Input bindings (include trigger)
  repeated ParameterBinding input_data = 3;

  // binding metadata from trigger
  map<string, TypedData> trigger_metadata = 4;
}

// Host requests worker to cancel invocation
message InvocationCancel {
  // Unique id for invocation
  string invocation_id = 2;

  // Time period before force shutdown
  google.protobuf.Duration grace_period = 1; // could also use absolute time
}

// Worker responds with status of Invocation
message InvocationResponse {
  // Unique id for invocation
  string invocation_id = 1;

  // Output binding data
  repeated ParameterBinding output_data = 2;

  // data returned from Function (for $return and triggers with return support)
  TypedData return_value = 4;

  // Status of the invocation (success/failure/canceled)
  StatusResult result = 3;
}

// Used to encapsulate data which could be a variety of types
message TypedData {
  oneof data {
    string string = 1;
    string json = 2;
    bytes bytes = 3;
    bytes stream = 4;
    RpcHttp http = 5;
	  sint64 int = 6;
    double double = 7;
  }
}

// Used to describe a given binding on invocation
message ParameterBinding {
  // Name for the binding
  string name = 1;

  // Data for the binding
  TypedData data = 2;
}

// Used to describe a given binding on load
message BindingInfo {
    // Indicates whether it is an input or output binding (or a fancy inout binding)
    enum Direction {
      in = 0;
      out = 1;
      inout = 2;
    }

    // Indicates the type of the data for the binding
    enum DataType {
      undefined = 0;
      string = 1;
      binary = 2;
      stream = 3;
    }

  // Type of binding (e.g. HttpTrigger)
  string type = 2;

  // Direction of the given binding
  Direction direction = 3;

  DataType data_type = 4;
}

// Used to send logs back to the Host 
message RpcLog {
  // Matching ILogger semantics
  // https://github.com/aspnet/Logging/blob/9506ccc3f3491488fe88010ef8b9eb64594abf95/src/Microsoft.Extensions.Logging/Logger.cs
  // Level for the Log
  enum Level {
    Trace = 0;
    Debug = 1;
    Information = 2;
    Warning = 3;
    Error = 4;
    Critical = 5;
    None = 6;
  }

  // Unique id for invocation (if exists)
  string invocation_id = 1;

  // TOD: This should be an enum
  // Category for the log (startup, load, invocation, etc.)
  string category = 2;

  // Level for the given log message
  Level level = 3;

  // Message for the given log
  string message = 4;

  // Id for the even associated with this log (if exists)
  string event_id = 5;

  // Exception (if exists)
  RpcException exception = 6;

  // json serialized property bag, or could use a type scheme like map<string, TypedData>
  string properties = 7;
}

// Encapsulates an Exception 
message RpcException {
  // Source of the exception
  string source = 3;

  // Stack trace for the exception
  string stack_trace = 1;

  // Textual message describing hte exception
  string message = 2;
}

// TODO - solidify this or remove it
message RpcHttp {
  string method = 1;
  string url = 2; 
  map<string,string> headers = 3;
  TypedData body = 4;
  map<string,string> params = 10;
  string status_code = 12;
  map<string,string> query = 15;
  bool enable_content_negotiation= 16;
  TypedData rawBody = 17;
}