chore(metrics): use kubert-prometheus-process metrics (#3742)

kubert-prometheus-process is a new crate that includes all of Linkerd's system
metrics and more. This also helps avoid annoying compilation build issues on
non-Linux systems.

Author: olix0r

Cargo.lock

@@ -1231,6 +1231,18 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "kubert-prometheus-process"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5b89e2a641a3f74c2e7366eb050282ac4a6194b63dae5294084215c457237e47"
+dependencies = [
+ "libc",
+ "procfs",
+ "prometheus-client",
+ "tracing",
+]
+
 [[package]]
 name = "kubert-prometheus-tokio"
 version = "0.2.0"
@@ -1272,7 +1284,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fc2f4eb4bc735547cfed7c0a4922cbd04a4655978c09b54f1f7b228750664c34"
 dependencies = [
  "cfg-if",
- "windows-targets 0.52.0",
+ "windows-targets 0.48.5",
 ]
 
 [[package]]
@@ -2029,9 +2041,9 @@ dependencies = [
  "http",
  "http-body",
  "hyper",
+ "kubert-prometheus-process",
  "linkerd-http-box",
  "linkerd-stack",
- "linkerd-system",
  "parking_lot",
  "prometheus-client",
  "quickcheck",
@@ -2549,15 +2561,6 @@ dependencies = [
  "tracing",
 ]
 
-[[package]]
-name = "linkerd-system"
-version = "0.1.0"
-dependencies = [
- "libc",
- "procfs",
- "tracing",
-]
-
 [[package]]
 name = "linkerd-tls"
 version = "0.1.0"

Cargo.toml

@@ -78,7 +78,6 @@ members = [
     "linkerd/stack",
     "linkerd/stack/metrics",
     "linkerd/stack/tracing",
-    "linkerd/system",
     "linkerd/tonic-stream",
     "linkerd/tonic-watch",
     "linkerd/tls",

linkerd/app/src/lib.rs

@@ -35,7 +35,7 @@ use tokio::{
     sync::mpsc,
     time::{self, Duration},
 };
-use tracing::{debug, info, info_span, Instrument};
+use tracing::{debug, error, info, info_span, Instrument};
 
 /// Spawns a sidecar proxy.
 ///
@@ -293,7 +293,10 @@ impl Config {
             })
         };
 
-        metrics::process::register(registry.sub_registry_with_prefix("process"));
+        if let Err(error) = metrics::process::register(registry.sub_registry_with_prefix("process"))
+        {
+            error!(%error, "Failed to register process metrics");
+        }
         registry.register("proxy_build_info", "Proxy build info", BUILD_INFO.metric());
 
         let admin = {

linkerd/metrics/Cargo.toml

@@ -8,7 +8,7 @@ publish = false
 
 [features]
 default = []
-process = ["dep:linkerd-system"]
+process = ["dep:kubert-prometheus-process"]
 stack = ["dep:linkerd-stack"]
 test_util = []
 
@@ -17,14 +17,14 @@ deflate = { version = "1", features = ["gzip"] }
 http = { workspace = true }
 http-body = { workspace = true }
 hyper = { workspace = true, features = ["deprecated", "http1", "http2"] }
+kubert-prometheus-process = { version = "0.2", optional = true }
 parking_lot = "0.12"
 prometheus-client = "0.23"
 tokio = { version = "1", features = ["time"] }
 tracing = "0.1"
 
 linkerd-http-box = { path = "../http/box" }
 linkerd-stack = { path = "../stack", optional = true }
-linkerd-system = { path = "../system", optional = true }
 
 [dev-dependencies]
 quickcheck = { version = "1", default-features = false }

linkerd/metrics/src/lib.rs

@@ -10,11 +10,12 @@ mod histogram;
 pub mod latency;
 #[cfg(feature = "stack")]
 mod new_metrics;
-#[cfg(feature = "process")]
-pub mod process;
 mod serve;
 mod store;
 
+#[cfg(feature = "process")]
+pub use kubert_prometheus_process as process;
+
 #[cfg(feature = "stack")]
 pub use self::new_metrics::NewMetrics;
 pub use self::{