chore: refactor grpc gen and project structure

introduce a new crate `lib/backends` that contains the protobuf files
along with the corresponding rust bindings. this allows flexible usage
by both the dataplane and controlplane crates.

Signed-off-by: Sanskar Jaiswal <[email protected]>

Cargo.toml

@@ -7,6 +7,7 @@ members = [
 	"dataplane/loader",
 	"tools/udp-test-server",
 	"xtask",
+	"lib/backends",
 ]
 exclude = ["dataplane/ebpf"]
 
@@ -16,6 +17,9 @@ license = "Apache-2.0"
 repository = "https://github.com/kubernetes-sigs/blixt"
 version = "0.3.0"
 
+# this should not include any crates that are linux only. doing so
+# will break the controlplane on macOS. this includes crates belonging
+# to this workspace that import third party linux only crates.
 [workspace.dependencies]
 anyhow = { version = "1", default-features = true }
 chrono = { version = "0.4.33", default-features = false }
@@ -41,3 +45,4 @@ tonic-build = { version = "0.11.0", default-features = false }
 tonic-health = { version = "0.11.0", default-features = false }
 tracing = { version = "0.1.37", default-features = false }
 tracing-subscriber = { version = "0.3", default-features = false }
+backends = { path = "./lib/backends" }

dataplane/api-server/Cargo.toml

@@ -8,14 +8,14 @@ version.workspace = true
 [dependencies]
 anyhow = { workspace = true }
 aya = { version = "0.13.1", features = ["async_tokio"] }
+backends = { workspace = true }
 clap = { workspace = true, features = ["derive"] }
 common = { path = "../common", features = ["user"] }
 libc = { workspace = true }
 log = { workspace = true }
 netlink-packet-core = { version = "0.7.0" }
 netlink-packet-route = { version = "0.20.1" }
 netlink-sys = { version = "0.8.7" }
-prost = { workspace = true }
 tokio = { workspace = true, features = [
     "macros",
     "rt",
@@ -26,9 +26,6 @@ tokio = { workspace = true, features = [
 tonic = { workspace = true, features = ["tls"] }
 tonic-health = { workspace = true }
 
-[build-dependencies]
-tonic-build = { workspace = true }
-
 [dev-dependencies]
 tempfile = "3.14.0"
 rcgen = "0.13.2"

dataplane/api-server/src/lib.rs

@@ -4,7 +4,6 @@ Copyright 2023 The Kubernetes Authors.
 SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
 */
 
-pub mod backends;
 pub mod config;
 pub mod netutils;
 pub mod server;
@@ -19,7 +18,7 @@ use aya::maps::{HashMap, MapData};
 use log::info;
 use tonic::transport::{Certificate, Identity, Server, ServerTlsConfig};
 
-use backends::backends_server::BackendsServer;
+use backends::backends::backends_server::BackendsServer;
 use common::{BackendKey, BackendList, ClientKey, LoadBalancerMapping};
 use config::TLSConfig;
 

dataplane/api-server/src/server.rs

@@ -12,9 +12,10 @@ use aya::maps::{HashMap, MapData, MapError};
 use tokio::sync::Mutex;
 use tonic::{Request, Response, Status};
 
-use crate::backends::backends_server::Backends;
-use crate::backends::{Confirmation, InterfaceIndexConfirmation, PodIp, Targets, Vip};
+use backends::backends::{Confirmation, InterfaceIndexConfirmation, PodIp, Targets, Vip};
+
 use crate::netutils::if_index_for_routing_ip;
+use backends::backends::backends_server::Backends;
 use common::{
     Backend, BackendKey, BackendList, ClientKey, LoadBalancerMapping, BACKENDS_ARRAY_CAPACITY,
 };

lib/backends/Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "backends"
+edition.workspace = true
+license.workspace = true
+repository.workspace = true
+version.workspace = true
+
+[dependencies]
+tonic = { workspace = true, features = ["codegen", "prost"] }
+prost = { workspace = true }
+tonic-build = { workspace = true, features = ["prost"] }
+
+[build-dependencies]
+tonic-build = { workspace = true, features = ["prost"] }

lib/backends/build.rs

@@ -0,0 +1,11 @@
+fn main() {
+    let proto_file = "./proto/backends.proto";
+
+    println!("building proto {}", proto_file);
+
+    tonic_build::configure()
+        .protoc_arg("--experimental_allow_proto3_optional")
+        .out_dir("./src")
+        .compile(&[proto_file], &["."])
+        .unwrap();
+}