Update to latest sysinfo prevents leaking fd-handlers (paritytech#6708)

* Ensure we close old file handles hold by sysinfo

* Dropping is needed unfortunately

* enable process refreshing, ignore result from refresh_process

* jumping to proposed patch

* switch to latest sysinfo

client/service/Cargo.toml

@@ -39,7 +39,7 @@ pin-project = "0.4.8"
 hash-db = "0.15.2"
 serde = "1.0.101"
 serde_json = "1.0.41"
-sysinfo = "0.14.3"
+sysinfo = "0.14.15"
 sc-keystore = { version = "2.0.0-rc5", path = "../keystore" }
 sp-io = { version = "2.0.0-rc5", path = "../../primitives/io" }
 sp-runtime = { version = "2.0.0-rc5", path = "../../primitives/runtime" }

client/service/src/metrics.rs

@@ -199,7 +199,7 @@ impl MetricsService {
 
 		Self {
 			metrics,
-			system: sysinfo::System::new(),
+			system: sysinfo::System::new_with_specifics(sysinfo::RefreshKind::new().with_processes()),
 			pid: Some(process.pid),
 		}
 	}
@@ -234,7 +234,7 @@ impl MetricsService {
 	fn inner_new(metrics: Option<PrometheusMetrics>) -> Self {
 		Self {
 			metrics,
-			system: sysinfo::System::new(),
+			system: sysinfo::System::new_with_specifics(sysinfo::RefreshKind::new().with_processes()),
 			pid: sysinfo::get_current_pid().ok(),
 		}
 	}
@@ -283,12 +283,11 @@ impl MetricsService {
 	#[cfg(all(any(unix, windows), not(target_os = "android"), not(target_os = "ios")))]
 	fn process_info_for(&mut self, pid: &sysinfo::Pid) -> ProcessInfo {
 		let mut info = ProcessInfo::default();
-		if self.system.refresh_process(*pid) {
-			let prc = self.system.get_process(*pid)
-				.expect("Above refresh_process succeeds, this must be Some(), qed");
+		self.system.refresh_process(*pid);
+		self.system.get_process(*pid).map(|prc| {
 			info.cpu_usage = prc.cpu_usage().into();
 			info.memory = prc.memory();
-		}
+		});
 		info
 	}