feat!: require --enable-logging flag to install tracing subscriber

src/bin/ant-devnet/cli.rs

@@ -44,7 +44,16 @@ pub struct Cli {
     #[arg(long)]
     pub manifest: Option<PathBuf>,
 
+    /// Enable logging output.
+    /// When omitted, the tracing subscriber is not installed and no log
+    /// records are emitted, even if the binary was built with the
+    /// `logging` feature. `--log-level` is ignored unless this flag is set.
+    #[cfg(feature = "logging")]
+    #[arg(long, env = "ANT_ENABLE_LOGGING")]
+    pub enable_logging: bool,
+
     /// Log level for devnet process.
+    #[cfg(feature = "logging")]
     #[arg(long, default_value = "info")]
     pub log_level: String,
 

src/bin/ant-devnet/main.rs

@@ -15,7 +15,7 @@ async fn main() -> color_eyre::Result<()> {
     let cli = Cli::parse();
 
     #[cfg(feature = "logging")]
-    {
+    if cli.enable_logging {
         use tracing_subscriber::{fmt, prelude::*, EnvFilter};
 
         let filter =

src/bin/ant-node/cli.rs

@@ -12,6 +12,7 @@ use std::path::PathBuf;
 #[derive(Parser, Debug)]
 #[command(name = "ant-node")]
 #[command(author, version, about, long_about = None)]
+#[allow(clippy::struct_excessive_bools)] // unrelated CLI toggles, not a state machine
 pub struct Cli {
     /// Root directory for node data.
     #[arg(long, env = "ANT_ROOT_DIR")]
@@ -61,6 +62,15 @@ pub struct Cli {
     #[arg(long, default_value = "9100", env = "ANT_METRICS_PORT")]
     pub metrics_port: u16,
 
+    /// Enable logging output.
+    /// When omitted, the tracing subscriber is not installed and no log
+    /// records are emitted, even if the binary was built with the
+    /// `logging` feature. The remaining `--log-*` options are ignored
+    /// unless this flag is set.
+    #[cfg(feature = "logging")]
+    #[arg(long, env = "ANT_ENABLE_LOGGING")]
+    pub enable_logging: bool,
+
     /// Log level.
     #[cfg(feature = "logging")]
     #[arg(long, value_enum, default_value = "info", env = "RUST_LOG")]

src/bin/ant-node/main.rs

@@ -9,18 +9,26 @@ use ant_node::config::BootstrapSource;
 use ant_node::NodeBuilder;
 use clap::Parser;
 use cli::Cli;
+#[cfg(feature = "logging")]
+use cli::CliLogFormat;
+#[cfg(feature = "logging")]
+use tracing_subscriber::prelude::*;
+#[cfg(feature = "logging")]
+use tracing_subscriber::{fmt, EnvFilter, Layer};
 
-/// Initialize the tracing subscriber when the `logging` feature is active.
+/// Initialize the tracing subscriber when the `logging` feature is active
+/// **and** the user passed `--enable-logging`.
 ///
-/// Returns a guard that must be held for the lifetime of the process to ensure
-/// buffered logs are flushed on shutdown.
+/// Returns `Ok(None)` when logging was not requested. Otherwise returns a
+/// guard (possibly `None` for stdout sinks) that must be held for the
+/// lifetime of the process to ensure buffered logs are flushed on shutdown.
 #[cfg(feature = "logging")]
 fn init_logging(
     cli: &Cli,
 ) -> color_eyre::Result<Option<tracing_appender::non_blocking::WorkerGuard>> {
-    use cli::CliLogFormat;
-    use tracing_subscriber::prelude::*;
-    use tracing_subscriber::{fmt, EnvFilter, Layer};
+    if !cli.enable_logging {
+        return Ok(None);
+    }
 
     let log_format = cli.log_format;
     let log_dir = cli.log_dir.clone();