wip: process collector

Cargo.toml

@@ -5,7 +5,13 @@ authors = ["Max Inden <[email protected]>"]
 edition = "2021"
 description = "Open Metrics client library allowing users to natively instrument applications."
 license = "Apache-2.0 OR MIT"
-keywords = ["openmetrics", "prometheus", "metrics", "instrumentation", "monitoring"]
+keywords = [
+  "openmetrics",
+  "prometheus",
+  "metrics",
+  "instrumentation",
+  "monitoring",
+]
 repository = "https://github.com/prometheus/client_rust"
 homepage = "https://github.com/prometheus/client_rust"
 documentation = "https://docs.rs/prometheus-client"
@@ -15,7 +21,7 @@ default = []
 protobuf = ["dep:prost", "dep:prost-types", "dep:prost-build"]
 
 [workspace]
-members = ["derive-encode"]
+members = ["derive-encode", "process-collector"]
 
 [dependencies]
 dtoa = "1.0"
@@ -35,7 +41,12 @@ quickcheck = "1"
 rand = "0.8.4"
 tide = "0.16"
 actix-web = "4"
-tokio = { version = "1", features = ["rt-multi-thread", "net", "macros", "signal"] }
+tokio = { version = "1", features = [
+  "rt-multi-thread",
+  "net",
+  "macros",
+  "signal",
+] }
 hyper = { version = "1.3.1", features = ["server", "http1"] }
 hyper-util = { version = "0.1.3", features = ["tokio"] }
 http-body-util = "0.1.1"

process-collector/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "process-collector"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+procfs = "0.17.0"
+prometheus-client = { path = "../" }

process-collector/src/lib.rs

@@ -0,0 +1,72 @@
+use procfs::process::Process;
+use prometheus_client::{
+    collector::Collector,
+    encoding::{DescriptorEncoder, EncodeMetric},
+    metrics::counter::ConstCounter,
+    registry::Unit,
+};
+
+#[derive(Debug)]
+pub struct ProcessCollector {
+    namespace: String,
+}
+
+impl Collector for ProcessCollector {
+    fn encode(&self, mut encoder: DescriptorEncoder) -> Result<(), std::fmt::Error> {
+        let tps = procfs::ticks_per_second();
+        // process_cpu_seconds_total Total user and system CPU time spent in seconds.
+        // process_max_fds Maximum number of open file descriptors.
+        // process_open_fds Number of open file descriptors.
+        // process_virtual_memory_bytes Virtual memory size in bytes.
+        // process_resident_memory_bytes Resident memory size in bytes.
+        // process_virtual_memory_max_bytes Maximum amount of virtual memory available in bytes.
+        // process_start_time_seconds Start time of the process since unix epoch in seconds.
+        // process_network_receive_bytes_total Number of bytes received by the process over the network.
+        // process_network_transmit_bytes_total Number of bytes sent by the process over the network.
+
+        if let Ok(proc) = Process::myself() {
+            if let Ok(stat) = proc.stat() {
+                let cpu_time = (stat.stime + stat.utime) / tps as u64;
+                let counter = ConstCounter::new(cpu_time);
+                let metric_encoder = encoder.encode_descriptor(
+                    "process_cpu_seconds_total",
+                    "Total user and system CPU time spent in seconds.",
+                    Some(&Unit::Seconds),
+                    counter.metric_type(),
+                )?;
+                counter.encode(metric_encoder)?;
+            }
+
+            if let Ok(limits) = proc.limits() {
+                let max_fds = match limits.max_open_files.soft_limit {
+                    procfs::process::LimitValue::Value(v) => v,
+                    procfs::process::LimitValue::Unlimited => 0,
+                };
+                let counter = ConstCounter::new(max_fds);
+                let metric_encoder = encoder.encode_descriptor(
+                    "process_max_fds",
+                    "Maximum number of open file descriptors.",
+                    None,
+                    counter.metric_type(),
+                )?;
+                counter.encode(metric_encoder)?;
+            }
+        }
+
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use prometheus_client::registry::Registry;
+
+    #[test]
+    fn register_process_collector() {
+        let mut registry = Registry::default();
+        registry.register_collector(Box::new(ProcessCollector {
+            namespace: String::new(),
+        }))
+    }
+}