thread labels through new metrics

Signed-off-by: Brian L. Troutwine <brian.troutwine@datadoghq.com>

Author: blt

lading/src/observer/linux.rs

@@ -292,10 +292,10 @@ impl Sampler {
             let vsize: u64 = stats.vsize;
 
             let labels = [
-                ("pid", format!("{pid}")),
-                ("exe", basename.clone()),
-                ("cmdline", cmdline.clone()),
-                ("comm", comm.clone()),
+                (String::from("pid"), format!("{pid}")),
+                (String::from("exe"), basename.clone()),
+                (String::from("cmdline"), cmdline.clone()),
+                (String::from("comm"), comm.clone()),
             ];
 
             // Number of pages that the process has in real memory.
@@ -363,8 +363,8 @@ impl Sampler {
                     let labels = [
                         ("pid", format!("{pid}")),
                         ("exe", basename.clone()),
-                        ("comm", comm.clone()),
                         ("cmdline", cmdline.clone()),
+                        ("comm", comm.clone()),
                     ];
 
                     gauge!("smaps.rss.sum", &labels).set(measures.rss as f64);
@@ -404,7 +404,7 @@ impl Sampler {
             // using the same heuristic as kubernetes:
             // total_usage - inactive_file
             let cgroup_path = v2::get_path(pid).await?;
-            v2::poll(cgroup_path).await?;
+            v2::poll(cgroup_path, &labels).await?;
         }
 
         gauge!("num_processes").set(total_processes as f64);

lading/src/observer/linux/cgroup/v2.rs

@@ -39,7 +39,7 @@ pub(crate) async fn get_path(pid: i32) -> Result<PathBuf, Error> {
 }
 
 /// Polls for any cgroup metrics that can be read, v2 version.
-pub(crate) async fn poll(path: PathBuf) -> Result<(), Error> {
+pub(crate) async fn poll(path: PathBuf, labels: &[(String, String)]) -> Result<(), Error> {
     let mut entries = fs::read_dir(&path).await?;
 
     while let Some(entry) = entries.next_entry().await? {
@@ -65,10 +65,10 @@ pub(crate) async fn poll(path: PathBuf) -> Result<(), Error> {
             // name.
             if let Ok(value) = content.parse::<f64>() {
                 // Single-valued
-                gauge!(metric_prefix).set(value);
+                gauge!(metric_prefix, labels).set(value);
             } else {
                 // Key-value pairs
-                if kv_pairs(content, &metric_prefix).is_err() {
+                if kv_pairs(content, &metric_prefix, labels).is_err() {
                     // File may fail to parse, for instance cgroup.controllers
                     // is a list of strings.
                     continue;
@@ -80,14 +80,14 @@ pub(crate) async fn poll(path: PathBuf) -> Result<(), Error> {
     Ok(())
 }
 
-fn kv_pairs(content: &str, metric_prefix: &str) -> Result<(), Error> {
+fn kv_pairs(content: &str, metric_prefix: &str, labels: &[(String, String)]) -> Result<(), Error> {
     for line in content.lines() {
         let mut parts = line.split_whitespace();
         let key = parts.next().expect("malformed key-value pair");
         let value_str = parts.next().expect("malformed key-value pair");
         let value: f64 = value_str.parse()?;
         let metric_name = format!("{metric_prefix}.{key}");
-        gauge!(metric_name).set(value);
+        gauge!(metric_name, labels).set(value);
     }
     Ok(())
 }