trickle errors on metrics setup

bin/src/main.rs

@@ -104,7 +104,7 @@ fn start(args: &cli::Args) -> Result<(), anyhow::Error> {
 
     util::setup_logging(&config);
     info!("Starting up");
-    util::setup_metrics(&config);
+    util::setup_metrics(&config).with_context(|| "Could not setup metrics")?;
     util::write_pid_file(&config).with_context(|| "PID file is not writeable")?;
 
     update_process_limits(&config)?;

bin/src/upgrade.rs

@@ -139,7 +139,7 @@ pub fn begin_new_main_process(
     let config = upgrade_data.config.clone();
 
     util::setup_logging(&config);
-    util::setup_metrics(&config);
+    util::setup_metrics(&config).with_context(|| "Could not setup metrics")?;
     //info!("new main got upgrade data: {:?}", upgrade_data);
 
     let mut server = CommandServer::from_upgrade_data(upgrade_data)?;

bin/src/util.rs

@@ -46,15 +46,16 @@ pub fn setup_logging(config: &Config) {
     );
 }
 
-pub fn setup_metrics(config: &Config) {
+pub fn setup_metrics(config: &Config) -> anyhow::Result<()> {
     if let Some(metrics) = config.metrics.as_ref() {
-        metrics::setup(
+        return metrics::setup(
             &metrics.address,
             "MAIN",
             metrics.tagged_metrics,
             metrics.prefix.clone(),
         );
     }
+    Ok(())
 }
 
 pub fn write_pid_file(config: &Config) -> Result<(), anyhow::Error> {

bin/src/worker.rs

@@ -158,7 +158,8 @@ pub fn begin_worker_process(
             worker_id,
             metrics.tagged_metrics,
             metrics.prefix.clone(),
-        );
+        )
+        .with_context(|| "Could not setup metrics")?;
     }
 
     let mut server = Server::new_from_config(

lib/src/metrics/mod.rs

@@ -11,6 +11,7 @@ use std::{
     time::Instant,
 };
 
+use anyhow::Context;
 use mio::net::UdpSocket;
 
 use crate::sozu_command::proxy::{
@@ -116,8 +117,8 @@ pub fn setup<O: Into<String>>(
     origin: O,
     use_tagged_metrics: bool,
     prefix: Option<String>,
-) {
-    let metrics_socket = udp_bind();
+) -> anyhow::Result<()> {
+    let metrics_socket = udp_bind()?;
 
     debug!(
         "setting up metrics: local address = {:#?}",
@@ -132,6 +133,7 @@ pub fn setup<O: Into<String>>(
         (*metrics.borrow_mut()).set_up_origin(origin.into());
         (*metrics.borrow_mut()).set_up_tagged_metrics(use_tagged_metrics);
     });
+    Ok(())
 }
 
 pub trait Subscriber {
@@ -273,9 +275,11 @@ impl Write for MetricSocket {
     }
 }
 
-// this should return a Result and trickle up the errors
-pub fn udp_bind() -> UdpSocket {
-    UdpSocket::bind("0.0.0.0:0".parse().unwrap()).expect("could not parse address")
+pub fn udp_bind() -> anyhow::Result<UdpSocket> {
+    let address = "0.0.0.0:0"
+        .parse()
+        .with_context(|| "could not parse 0.0.0.0:0")?;
+    UdpSocket::bind(address).with_context(|| "Could not bind to 0.0.0.0:0 udp socket")
 }
 
 #[macro_export]