add: Go module, proto definitions

cmd/signaler/main.go

@@ -0,0 +1,7 @@
+package main
+
+import "fmt"
+
+func main() {
+	fmt.Printf("Hello world!\n")
+}

go.mod

@@ -0,0 +1,3 @@
+module github.com/chathaway-codes/home-sensors/v2
+
+go 1.21.1

proto/signaler_service.proto

@@ -0,0 +1,76 @@
+syntax = "proto3";
+
+service SignalerService {
+    rpc ListCameras(ListCamerasRequest) returns (ListCamerasResponse);
+
+    // CreateSession creates a new session that can be seen bv the provided Camera and Peer.
+    //
+    // Optionally, wait_for_update can be set to prevent returning until the Camera has seen the
+    // session request, populated candidates, and returned a session offer.
+    rpc CreateSession(CreateSessionRequest) returns (Session);
+    // UpdateSession updates the session
+    rpc UpdateSession(UpdateSessionRequest) returns (Session);
+    // ListSessions lists all sessions the client should consider.
+    //
+    // TODO: it would be better if we could alert a camera to poll for sessions
+    // i.e., with websockets (or streaming RPCs).
+    rpc ListSessions(ListSessionsRequest) returns (ListSessionsResponse);
+}
+
+message ListCamerasRequest {}
+
+message ListCamerasResponse {
+    repeated Camera cameras = 1;
+}
+
+message CreateSessionRequest {
+    Session session = 1;
+
+    // If true, will keep the connection alive until an update is received.
+    // This is useful if we need to wait for a remote to detect the session
+    // request and update it with their candidates, offer, or answer.
+    bool wait_for_update = 2;
+}
+
+message UpdateSessionRequest {
+    Session session = 1;
+
+    // If true, will keep the connection alive until an update is received.
+    // This is useful if we need to wait for a remote to detect the session
+    // request and update it with their candidates, offer, or answer.
+    bool wait_for_update = 2;
+}
+
+message Camera {
+    message Identifier {
+        string id = 1;
+    }
+    Identifier identifier = 1;
+}
+
+message IceCandidate {
+    // Copied from https://pkg.go.dev/github.com/pion/webrtc/v4#ICECandidateInit
+    string candidate = 1;
+    optional string sdp_mid = 2;
+    optional int32 sdp_line_index = 3;
+    optional string username_fragment = 4;
+}
+
+message IceSessionDescription {
+    // Copied from https://pkg.go.dev/github.com/pion/webrtc/v4#SessionDescription
+    int sdp_type = 1;
+    string sdp = 2;
+}
+
+message Session {
+    message Identifier {
+        string id = 1;
+    }
+    Identifier id = 1;
+    Camera.Identifier camera = 2;
+    repeated IceCandidate client_ice_candidates = 3;
+    repeated IceCandidate camera_ice_candidates = 4;
+
+    IceSessionDescription camera_offer = 5;
+    IceSessionDescription client_answer = 6;
+}