chore(cli-utils): metrics args

Author: refcell

crates/shared/cli-utils/Cargo.toml

@@ -27,9 +27,9 @@ kona-registry.workspace = true
 
 # Tracing
 tracing.workspace = true
+reth-node-core.workspace = true
 tracing-appender.workspace = true
 tracing-subscriber = { workspace = true, features = ["fmt", "env-filter", "json", "tracing-log"] }
-reth-node-core.workspace = true
 
 # Metrics
 metrics-process = { workspace = true, features = ["metrics-rs"] }

crates/shared/cli-utils/src/args.rs

@@ -7,7 +7,8 @@ use clap::{ArgAction, Parser};
 use kona_registry::OPCHAINS;
 
 use crate::{
-    FileLogConfig, LogConfig, LogFormat, LogRotation, StdoutLogConfig, verbosity_to_level_filter,
+    FileLogConfig, LogConfig, LogFormat, LogRotation, MetricsArgs, StdoutLogConfig,
+    verbosity_to_level_filter,
 };
 
 /// Log-related CLI arguments.
@@ -98,6 +99,10 @@ pub struct GlobalArgs {
     /// Logging configuration.
     #[command(flatten)]
     pub logging: LogArgs,
+
+    /// Prometheus CLI arguments.
+    #[command(flatten)]
+    pub metrics: MetricsArgs,
 }
 
 impl GlobalArgs {

crates/shared/cli-utils/src/lib.rs

@@ -9,12 +9,18 @@ pub use sigsegv::SigsegvHandler;
 mod backtrace;
 pub use backtrace::Backtracing;
 
-mod args;
-pub use args::{GlobalArgs, LogArgs};
+mod metrics;
+pub use metrics::MetricsArgs;
 
 mod prometheus;
 pub use prometheus::PrometheusServer;
 
+mod args;
+pub use args::{GlobalArgs, LogArgs};
+
+mod styles;
+pub use styles::CliStyles;
+
 mod logging;
 pub use logging::{
     FileLogConfig, LogConfig, LogFormat, LogRotation, StdoutLogConfig, verbosity_to_level_filter,
@@ -28,6 +34,3 @@ pub use version::Version;
 
 mod runtime;
 pub use runtime::RuntimeManager;
-
-mod styles;
-pub use styles::CliStyles;

crates/shared/cli-utils/src/metrics.rs

@@ -0,0 +1,117 @@
+//! Utility module to house implementation and declaration of MetricsArgs since it's being used in
+//! multiple places, it's just being referenced from this module.
+
+use std::net::IpAddr;
+
+use clap::Parser;
+
+use crate::PrometheusServer;
+
+/// Configuration for Prometheus metrics.
+#[derive(Debug, Clone, Parser)]
+#[command(next_help_heading = "Metrics")]
+pub struct MetricsArgs {
+    /// Controls whether Prometheus metrics are enabled. Disabled by default.
+    #[arg(
+        long = "metrics.enabled",
+        global = true,
+        default_value_t = false,
+        env = "KONA_METRICS_ENABLED"
+    )]
+    pub enabled: bool,
+
+    /// The port to serve Prometheus metrics on.
+    #[arg(long = "metrics.port", global = true, default_value = "9090", env = "KONA_METRICS_PORT")]
+    pub port: u16,
+
+    /// The IP address to use for Prometheus metrics.
+    #[arg(
+        long = "metrics.addr",
+        global = true,
+        default_value = "0.0.0.0",
+        env = "KONA_METRICS_ADDR"
+    )]
+    pub addr: IpAddr,
+}
+
+impl Default for MetricsArgs {
+    fn default() -> Self {
+        Self::parse_from::<[_; 0], &str>([])
+    }
+}
+
+impl MetricsArgs {
+    /// Initialize the Prometheus metrics recorder.
+    ///
+    /// This function should be called at the beginning of the program.
+    pub fn init(&self) -> Result<(), metrics_exporter_prometheus::BuildError> {
+        if self.enabled {
+            PrometheusServer::init(self.addr, self.port, None)?;
+        }
+
+        Ok(())
+    }
+
+    /// Initialize the Prometheus metrics recorder and run a callback to initialize
+    /// subsystem-specific metrics if metrics are enabled.
+    ///
+    /// This function should be called at the beginning of the program.
+    pub fn init_with<F>(&self, f: F) -> Result<(), metrics_exporter_prometheus::BuildError>
+    where
+        F: FnOnce(),
+    {
+        if self.enabled {
+            PrometheusServer::init(self.addr, self.port, None)?;
+            f();
+        }
+
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::net::{IpAddr, Ipv4Addr};
+
+    use clap::Parser;
+
+    use super::*;
+
+    /// Helper struct to parse MetricsArgs within a test CLI structure.
+    #[derive(Parser, Debug)]
+    struct TestCli {
+        #[command(flatten)]
+        metrics: MetricsArgs,
+    }
+
+    #[test]
+    fn test_default_metrics_args() {
+        let cli = TestCli::parse_from(["test_app"]);
+        assert!(!cli.metrics.enabled, "Default for metrics.enabled should be false.");
+        assert_eq!(cli.metrics.port, 9090, "Default for metrics.port should be 9090.");
+        assert_eq!(
+            cli.metrics.addr,
+            IpAddr::V4(Ipv4Addr::new(0, 0, 0, 0)),
+            "Default for metrics.addr should be 0.0.0.0."
+        );
+    }
+
+    #[test]
+    fn test_metrics_args_from_cli() {
+        let cli = TestCli::parse_from([
+            "test_app",
+            "--metrics.enabled",
+            "--metrics.port",
+            "9999",
+            "--metrics.addr",
+            "127.0.0.1",
+        ]);
+        assert!(cli.metrics.enabled, "metrics.enabled should be true.");
+        assert_eq!(cli.metrics.port, 9999, "metrics.port should be parsed from CLI.");
+        assert_eq!(
+            cli.metrics.addr,
+            IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)),
+            "metrics.addr should be parsed from CLI."
+        );
+    }
+}

crates/shared/cli-utils/src/tracing.rs

@@ -78,6 +78,13 @@ impl LogConfig {
         let filter =
             EnvFilter::builder().with_default_directive(self.global_level.into()).from_env_lossy();
 
+        self.init_tracing_subscriber_with_filter(filter)
+    }
+
+    /// Initialize the tracing subscriber with a custom filter.
+    ///
+    /// This sets the global default subscriber. Should only be called once.
+    pub fn init_tracing_subscriber_with_filter(&self, filter: EnvFilter) -> eyre::Result<()> {
         let registry = tracing_subscriber::registry().with(filter);
 
         // Build stdout layer