Add feature flag for Kubernetes discovery

src/rpc/system.rs

@@ -29,6 +29,7 @@ use garage_util::persister::Persister;
 use garage_util::time::*;
 
 use crate::consul::*;
+#[cfg(feature = "kubernetes-discovery")]
 use crate::kubernetes::*;
 use crate::layout::*;
 use crate::ring::*;
@@ -90,12 +91,10 @@ pub struct System {
 	rpc_listen_addr: SocketAddr,
 	rpc_public_addr: Option<SocketAddr>,
 	bootstrap_peers: Vec<(NodeID, SocketAddr)>,
-	consul_host: Option<String>,
-	consul_service_name: Option<String>,
 
-	kubernetes_service_name: Option<String>,
-	kubernetes_namespace: Option<String>,
-	kubernetes_skip_crd: bool,
+	consul_discovery: Option<ConsulDiscoveryParam>,
+	#[cfg(feature = "kubernetes-discovery")]
+	kubernetes_discovery: Option<KubernetesDiscoveryParam>,
 
 	replication_factor: usize,
 
@@ -228,15 +227,53 @@ impl System {
 		let ring = Ring::new(cluster_layout, replication_factor);
 		let (update_ring, ring) = watch::channel(Arc::new(ring));
 
+		let rpc_public_addr = match config.rpc_public_addr {
+			Some(a) => Some(a),
+			None => {
+				let addr =
+					get_default_ip().map(|ip| SocketAddr::new(ip, config.rpc_bind_addr.port()));
+				if let Some(a) = addr {
+					warn!("Using autodetected rpc_public_addr: {}. Consider specifying it explicitly in configuration file if possible.", a);
+				}
+				addr
+			}
+		};
+
 		let netapp = NetApp::new(GARAGE_VERSION_TAG, network_key, node_key);
 		let fullmesh = FullMeshPeeringStrategy::new(
 			netapp.clone(),
 			config.bootstrap_peers.clone(),
-			config.rpc_public_addr,
+			rpc_public_addr,
 		);
 
 		let system_endpoint = netapp.endpoint(SYSTEM_RPC_PATH.into());
 
+		let consul_discovery = match (&config.consul_host, &config.consul_service_name) {
+			(Some(ch), Some(csn)) => Some(ConsulDiscoveryParam {
+				consul_host: ch.to_string(),
+				service_name: csn.to_string(),
+			}),
+			_ => None,
+		};
+
+		#[cfg(feature = "kubernetes-discovery")]
+		let kubernetes_discovery = match (
+			&config.kubernetes_service_name,
+			&config.kubernetes_namespace,
+		) {
+			(Some(ksn), Some(kn)) => Some(KubernetesDiscoveryParam {
+				service_name: ksn.to_string(),
+				namespace: kn.to_string(),
+				skip_crd: config.kubernetes_skip_crd,
+			}),
+			_ => None,
+		};
+
+		#[cfg(not(feature = "kubernetes-discovery"))]
+		if config.kubernetes_service_name.is_some() || config.kubernetes_namespace.is_some() {
+			warn!("Kubernetes discovery is not enabled in this build.");
+		}
+
 		let sys = Arc::new(System {
 			id: netapp.id.into(),
 			persist_cluster_layout,
@@ -249,13 +286,11 @@ impl System {
 			system_endpoint,
 			replication_factor,
 			rpc_listen_addr: config.rpc_bind_addr,
-			rpc_public_addr: config.rpc_public_addr,
+			rpc_public_addr,
 			bootstrap_peers: config.bootstrap_peers.clone(),
-			consul_host: config.consul_host.clone(),
-			consul_service_name: config.consul_service_name.clone(),
-			kubernetes_service_name: config.kubernetes_service_name.clone(),
-			kubernetes_namespace: config.kubernetes_namespace.clone(),
-			kubernetes_skip_crd: config.kubernetes_skip_crd,
+			consul_discovery,
+			#[cfg(feature = "kubernetes-discovery")]
+			kubernetes_discovery,
 
 			ring,
 			update_ring: Mutex::new(update_ring),
@@ -280,23 +315,22 @@ impl System {
 	// ---- INTERNALS ----
 
 	async fn advertise_to_consul(self: Arc<Self>) -> Result<(), Error> {
-		let (consul_host, consul_service_name) =
-			match (&self.consul_host, &self.consul_service_name) {
-				(Some(ch), Some(csn)) => (ch, csn),
-				_ => return Ok(()),
-			};
+		let c = match &self.consul_discovery {
+			Some(c) => c,
+			_ => return Ok(()),
+		};
 
 		let rpc_public_addr = match self.rpc_public_addr {
 			Some(addr) => addr,
 			None => {
-				warn!("Not advertising to Consul because rpc_public_addr is not defined in config file.");
+				warn!("Not advertising to Consul because rpc_public_addr is not defined in config file and could not be autodetected.");
 				return Ok(());
 			}
 		};
 
 		publish_consul_service(
-			consul_host,
-			consul_service_name,
+			&c.consul_host,
+			&c.service_name,
 			self.netapp.id,
 			&self.local_status.load_full().hostname,
 			rpc_public_addr,
@@ -305,36 +339,24 @@ impl System {
 		.err_context("Error while publishing Consul service")
 	}
 
-	fn get_default_ip() -> IpAddr {
-		pnet::datalink::interfaces()
-			.iter()
-			.find(|e| e.is_up() && !e.is_loopback() && !e.ips.is_empty())
-			.unwrap()
-			.ips
-			.first()
-			.unwrap()
-			.ip()
-	}
-
+	#[cfg(feature = "kubernetes-discovery")]
 	async fn advertise_to_kubernetes(self: Arc<Self>) -> Result<(), Error> {
-		let (kubernetes_service_name, kubernetes_namespace) =
-			match (&self.kubernetes_service_name, &self.kubernetes_namespace) {
-				(Some(ch), Some(csn)) => (ch, csn),
-				_ => return Ok(()),
-			};
+		let k = match &self.kubernetes_discovery {
+			Some(k) => k,
+			_ => return Ok(()),
+		};
 
-		let rpc_public_addr =
-			match self.rpc_public_addr {
-				Some(addr) => addr,
-				None => {
-					warn!("No rpc_public_addr configured, using first address on first network interface");
-					SocketAddr::new(Self::get_default_ip(), self.rpc_listen_addr.port())
-				}
-			};
+		let rpc_public_addr = match self.rpc_public_addr {
+			Some(addr) => addr,
+			None => {
+				warn!("Not advertising to Kubernetes because rpc_public_addr is not defined in config file and could not be autodetected.");
+				return Ok(());
+			}
+		};
 
 		publish_kubernetes_node(
-			kubernetes_service_name,
-			kubernetes_namespace,
+			&k.service_name,
+			&k.namespace,
 			self.netapp.id,
 			&self.local_status.load_full().hostname,
 			rpc_public_addr,
@@ -513,16 +535,6 @@ impl System {
 	}
 
 	async fn discovery_loop(self: &Arc<Self>, mut stop_signal: watch::Receiver<bool>) {
-		let consul_config = match (&self.consul_host, &self.consul_service_name) {
-			(Some(ch), Some(csn)) => Some((ch.clone(), csn.clone())),
-			_ => None,
-		};
-
-		let kubernetes_config = match (&self.kubernetes_service_name, &self.kubernetes_namespace) {
-			(Some(ch), Some(csn)) => Some((ch.clone(), csn.clone())),
-			_ => None,
-		};
-
 		while !*stop_signal.borrow() {
 			let not_configured = !self.ring.borrow().layout.check();
 			let no_peers = self.fullmesh.get_peer_list().len() < self.replication_factor;
@@ -545,8 +557,8 @@ impl System {
 				}
 
 				// Fetch peer list from Consul
-				if let Some((consul_host, consul_service_name)) = &consul_config {
-					match get_consul_nodes(consul_host, consul_service_name).await {
+				if let Some(c) = &self.consul_discovery {
+					match get_consul_nodes(&c.consul_host, &c.service_name).await {
 						Ok(node_list) => {
 							ping_list.extend(node_list);
 						}
@@ -557,8 +569,9 @@ impl System {
 				}
 
 				// Fetch peer list from Kubernetes
-				if let Some((kubernetes_service_name, kubernetes_namespace)) = &kubernetes_config {
-					if !self.kubernetes_skip_crd {
+				#[cfg(feature = "kubernetes-discovery")]
+				if let Some(k) = &self.kubernetes_discovery {
+					if !k.skip_crd {
 						match create_kubernetes_crd().await {
 							Ok(()) => (),
 							Err(e) => {
@@ -567,8 +580,7 @@ impl System {
 						};
 					}
 
-					match get_kubernetes_nodes(kubernetes_service_name, kubernetes_namespace).await
-					{
+					match get_kubernetes_nodes(&k.service_name, &k.namespace).await {
 						Ok(node_list) => {
 							ping_list.extend(node_list);
 						}
@@ -593,6 +605,8 @@ impl System {
 			}
 
 			self.background.spawn(self.clone().advertise_to_consul());
+
+			#[cfg(feature = "kubernetes-discovery")]
 			self.background
 				.spawn(self.clone().advertise_to_kubernetes());
 
@@ -657,3 +671,23 @@ impl EndpointHandler<SystemRpc> for System {
 		}
 	}
 }
+
+fn get_default_ip() -> Option<IpAddr> {
+	pnet_datalink::interfaces()
+		.iter()
+		.find(|e| e.is_up() && !e.is_loopback() && !e.ips.is_empty())
+		.and_then(|e| e.ips.first())
+		.map(|a| a.ip())
+}
+
+struct ConsulDiscoveryParam {
+	consul_host: String,
+	service_name: String,
+}
+
+#[cfg(feature = "kubernetes-discovery")]
+struct KubernetesDiscoveryParam {
+	service_name: String,
+	namespace: String,
+	skip_crd: bool,
+}