add an "inert" mode to tfclient which does not link to nebula, allowing builds on platforms where CGo is unsupported

tfclient/Cargo.toml

@@ -31,7 +31,7 @@ base64-serde = "0.7.0"
 dnapi-rs = { version = "0.1", path = "../dnapi-rs" }
 serde_yaml = "0.9.19"
 openssl-sys = { version = "0.9.83", features = ["vendored"] }
-nebula-ffi = { version = "0.1", path = "../nebula-ffi" }
+nebula-ffi = { version = "0.1", path = "../nebula-ffi", optional = true }
 
 [build-dependencies]
 serde = { version = "1.0.157", features = ["derive"] }
@@ -49,3 +49,6 @@ license-file = "LICENSE.txt"
 maintainer-scripts = "debian/"
 systemd-units = { enable = false, unit-name = "tfclient@" }
 
+[features]
+default = ["linked-nebula"]
+linked-nebula = ["nebula-ffi"]

tfclient/src/main.rs

@@ -18,7 +18,13 @@ pub mod apiworker;
 pub mod config;
 pub mod daemon;
 pub mod dirs;
+
+#[cfg(feature = "linked-nebula")]
 pub mod nebulaworker;
+#[cfg(not(feature = "linked-nebula"))]
+#[path = "nebulaworker_inert.rs"]
+pub mod nebulaworker;
+
 pub mod socketclient;
 pub mod socketworker;
 pub mod timerworker;

tfclient/src/nebulaworker_inert.rs

@@ -0,0 +1,15 @@
+// Code to handle the nebula worker
+// This is an inert version of the nebula worker that does nothing, used when linking to nebula is diabled.
+// This is useful if you wish to run your own nebula binary, for example on platforms where CGo does not work.
+
+use crate::config::TFClientConfig;
+use crate::daemon::ThreadMessageSender;
+use std::sync::mpsc::Receiver;
+
+pub enum NebulaWorkerMessage {
+    Shutdown,
+    ConfigUpdated,
+    WakeUp,
+}
+
+pub fn nebulaworker_main(_config: TFClientConfig, _instance: String, _transmitter: ThreadMessageSender, _rx: Receiver<NebulaWorkerMessage>) {}