feat(examples): Send Logs to Loki (#321)

* feat(examples): loki tracing

* feat(examples): loki tracing

* feat(examples): loki tracing

* fixes

examples/trusted-sync/Cargo.toml

@@ -18,11 +18,12 @@ kona-derive = { path = "../../crates/derive", version = "0.0.2", features = ["se
 
 # Custom dependencies
 lazy_static = "1.5.0"
+tracing-loki = "0.2.5"
 reqwest = "0.12"
 actix-web = "4.8.0"
 prometheus = { version = "0.13.4", features = ["process"] }
 tokio = { version = "1.37.0", features = ["full"] }
-tracing-subscriber = "0.3.18"
+tracing-subscriber = { version = "0.3.18", features = ["fmt"] }
 clap = { version = "4.5.4", features = ["derive", "env"] }
 serde = { version = "1.0.198", features = ["derive"] }
 alloy-provider = { version = "0.1", default-features = false }

examples/trusted-sync/run.sh

@@ -7,4 +7,6 @@
   --start-l2-block $START_L2_BLOCK \
   --metrics-server-addr $METRICS_SERVER_ADDR \
   --metrics-server-port $METRICS_SERVER_PORT \
+  --loki-server-addr $LOKI_SERVER_ADDR \
+  --loki-server-port $LOKI_SERVER_PORT \
   -vvv

examples/trusted-sync/src/cli.rs

@@ -9,6 +9,8 @@ const L2_RPC_URL: &str = "L2_RPC_URL";
 const BEACON_URL: &str = "BEACON_URL";
 const DEFAULT_METRICS_SERVER_ADDR: &str = "127.0.0.1";
 const DEFAULT_METRICS_SERVER_PORT: u16 = 9000;
+const DEFAULT_LOKI_SERVER_ADDR: &str = "127.0.0.1";
+const DEFAULT_LOKI_SERVER_PORT: u16 = 3133;
 
 /// The host binary CLI application arguments.
 #[derive(Parser, Clone, serde::Serialize, serde::Deserialize)]
@@ -34,6 +36,12 @@ pub struct Cli {
     /// The metrics server port.
     #[clap(long, help = "Port of the metrics server")]
     pub metrics_server_port: Option<u16>,
+    /// The address of the loki server.
+    #[clap(long, help = "Address of the loki server")]
+    pub loki_server_addr: Option<String>,
+    /// The loki server port.
+    #[clap(long, help = "Port of the loki server")]
+    pub loki_server_port: Option<u16>,
 }
 
 impl Cli {
@@ -48,6 +56,16 @@ impl Cli {
         )
     }
 
+    /// Returns the full loki server address.
+    pub fn loki_addr(&self) -> Url {
+        let str = format!(
+            "http://{}:{}",
+            self.loki_server_addr.clone().unwrap_or_else(|| DEFAULT_LOKI_SERVER_ADDR.to_string()),
+            self.loki_server_port.unwrap_or(DEFAULT_LOKI_SERVER_PORT)
+        );
+        Url::parse(&str).expect("Failed to parse loki server address")
+    }
+
     /// Returns the l1 rpc url from CLI or environment variable.
     pub fn l1_rpc_url(&self) -> Result<Url> {
         let url = if let Some(s) = self.l1_rpc_url.clone() {

examples/trusted-sync/src/main.rs

@@ -14,7 +14,8 @@ const LOG_TARGET: &str = "trusted-sync";
 #[actix_web::main]
 async fn main() -> Result<()> {
     let cfg = cli::Cli::parse();
-    telemetry::init(cfg.v)?;
+    let loki_addr = cfg.loki_addr();
+    telemetry::init(cfg.v, loki_addr).await?;
     let addr = cfg.metrics_server_addr();
     let handle = tokio::spawn(async { sync(cfg).await });
     tokio::select! {

examples/trusted-sync/src/telemetry.rs

@@ -1,15 +1,28 @@
 use anyhow::{anyhow, Result};
+use reqwest::Url;
 use tracing::Level;
+use tracing_subscriber::{layer::SubscriberExt, prelude::*};
 
-pub fn init(v: u8) -> Result<()> {
-    let subscriber = tracing_subscriber::fmt()
-        .with_max_level(match v {
+pub async fn init(v: u8, addr: Url) -> Result<()> {
+    let (loki_layer, task) = tracing_loki::builder()
+        .label("environment", "production")
+        .map_err(|e| anyhow!(e))?
+        .extra_field("pid", format!("{}", std::process::id()))
+        .map_err(|e| anyhow!(e))?
+        .build_url(addr)
+        .map_err(|e| anyhow!(e))?;
+
+    let std_layer = tracing_subscriber::fmt::Layer::default().with_writer(
+        std::io::stdout.with_max_level(match v {
             0 => Level::ERROR,
             1 => Level::WARN,
             2 => Level::INFO,
             3 => Level::DEBUG,
             _ => Level::TRACE,
-        })
-        .finish();
-    tracing::subscriber::set_global_default(subscriber).map_err(|e| anyhow!(e))
+        }),
+    );
+    let subscriber = tracing_subscriber::registry().with(loki_layer).with(std_layer);
+    tracing::subscriber::set_global_default(subscriber).map_err(|e| anyhow!(e))?;
+    tokio::spawn(task);
+    Ok(())
 }

justfile

@@ -102,4 +102,6 @@ docker-run-ts:
     -e START_L2_BLOCK=$START_L2_BLOCK \
     -e METRICS_SERVER_ADDR=$METRICS_SERVER_ADDR \
     -e METRICS_SERVER_PORT=$METRICS_SERVER_PORT \
+    -e LOKI_SERVER_ADDR=$LOKI_SERVER_ADDR \
+    -e LOKI_SERVER_PORT=$LOKI_SERVER_PORT \
     trusted-sync