chore: improve debugging/observability

Cargo.toml

@@ -18,7 +18,7 @@ name = "zenith-builder-example"
 path = "bin/builder.rs"
 
 [dependencies]
-init4-bin-base = { version = "0.18.0-rc.10", features = ["perms", "aws", "pylon"] }
+init4-bin-base = { version = "0.18.0-rc.12", features = ["perms", "aws", "pylon"] }
 
 signet-constants = { version = "0.16.0-rc.13" }
 signet-sim = { version = "0.16.0-rc.13" }
@@ -50,6 +50,8 @@ axum = "0.7.5"
 backon = { version = "1.6.0", features = ["tokio-sleep"] }
 eyre = "0.6.12"
 futures-util = "0.3.31"
+git-version = "0.3.9"
+itertools = "0.14.0"
 openssl = { version = "0.10", features = ["vendored"] }
 reqwest = { version = "0.12.22", features = ["blocking", "json"] }
 thiserror = "2.0.17"

bin/builder.rs

@@ -1,23 +1,66 @@
 #![recursion_limit = "256"]
 
 use builder::{
+    config::{BuilderConfig, env_var_info},
     service::serve_builder,
     tasks::{
         block::sim::SimulatorTask, cache::CacheTasks, env::EnvTask, metrics::MetricsTask,
         submit::FlashbotsTask,
     },
 };
-use init4_bin_base::deps::tracing::{info, info_span};
+use eyre::bail;
+use git_version::git_version;
+use init4_bin_base::{
+    deps::tracing::{info, info_span},
+    utils::from_env::FromEnv,
+};
 use tokio::select;
 
+const GIT_COMMIT: &str =
+    git_version!(args = ["--always", "--match=", "--abbrev=7"], fallback = "unknown");
+const PKG_VERSION: &str = env!("CARGO_PKG_VERSION");
+
+fn should_print_help() -> bool {
+    std::env::args().any(|arg| {
+        let lowercase_arg = arg.to_ascii_lowercase();
+        lowercase_arg == "-h" || lowercase_arg == "--help"
+    })
+}
+
+fn print_help() {
+    let version = env!("CARGO_PKG_VERSION");
+    let env_vars = env_var_info();
+    println!(
+        r#"Signet block builder v{version}
+
+Run with no args. Configuration is via the following environment variables:
+{env_vars}
+"#
+    )
+}
+
 // Note: Must be set to `multi_thread` to support async tasks.
 // See: https://docs.rs/tokio/latest/tokio/attr.main.html
 #[tokio::main(flavor = "multi_thread")]
 async fn main() -> eyre::Result<()> {
-    let _guard = init4_bin_base::init4();
+    if should_print_help() {
+        print_help();
+        return Ok(());
+    }
+
+    if let Err(e) = BuilderConfig::check_inventory() {
+        for item in e {
+            eprintln!("missing environment variable: {}: {}", item.var, item.description);
+        }
+        bail!(
+            "missing at least one required environment variable; run with '--help' to see the list"
+        );
+    }
+
+    let config = builder::config_from_env();
     let init_span_guard = info_span!("builder initialization").entered();
 
-    builder::config_from_env();
+    info!(pkg_version = PKG_VERSION, git_commit = GIT_COMMIT, "starting builder");
 
     // Pre-load the KZG settings in a separate thread.
     //
@@ -45,7 +88,7 @@ async fn main() -> eyre::Result<()> {
     let build_jh = simulator_task.spawn_simulator_task(cache_system.sim_cache, submit_channel);
 
     // Start the healthcheck server
-    let server = serve_builder(([0, 0, 0, 0], builder::config().builder_port));
+    let server = serve_builder(([0, 0, 0, 0], config.builder_port));
 
     // We have finished initializing the builder, so we can drop the init span
     // guard.