rpc/system_metrics.rs: Added rustversion label to garage_build_info metric.

Cargo.lock

@@ -1309,6 +1309,7 @@ dependencies = [
  "opentelemetry",
  "rand",
  "rmp-serde",
+ "rustc_version",
  "serde",
  "serde_json",
  "sha2 0.10.6",

src/rpc/system_metrics.rs

@@ -31,10 +31,10 @@ impl SystemMetrics {
 				.u64_value_observer("garage_build_info", move |observer| {
 					observer.observe(
 						1,
-						&[KeyValue::new(
-							"version",
-							garage_util::version::garage_version(),
-						)],
+						&[
+							KeyValue::new("rustversion", garage_util::version::rust_version()),
+							KeyValue::new("version", garage_util::version::garage_version()),
+						],
 					)
 				})
 				.with_description("Garage build info")

src/util/Cargo.toml

@@ -47,6 +47,9 @@ hyper = "0.14"
 
 opentelemetry = { version = "0.17", features = [ "rt-tokio", "metrics", "trace" ] }
 
+[build-dependencies]
+rustc_version = "0.4.0"
+
 [dev-dependencies]
 mktemp = "0.5"
 

src/util/build.rs

@@ -0,0 +1,8 @@
+use rustc_version::version;
+
+fn main() {
+	// Acquire the version of Rust used to compile, this is added as a label to
+	// the garage_build_info metric.
+	let v = version().unwrap();
+	println!("cargo:rustc-env=RUSTC_VERSION={v}");
+}

src/util/version.rs

@@ -26,3 +26,7 @@ pub fn init_version(version: &'static str) {
 pub fn init_features(features: &'static [&'static str]) {
 	FEATURES.store(Some(Arc::new(features)));
 }
+
+pub fn rust_version() -> &'static str {
+	env!("RUSTC_VERSION")
+}