Add metrics for log levels

Cargo.lock

@@ -2455,6 +2455,8 @@ dependencies = [
 name = "logging"
 version = "0.1.0"
 dependencies = [
+ "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lighthouse_metrics 0.1.0",
  "slog 2.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "slog-term 2.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]

eth2/utils/logging/Cargo.toml

@@ -7,3 +7,5 @@ edition = "2018"
 [dependencies]
 slog = "2.5.2"
 slog-term = "2.4.2"
+lighthouse_metrics = { path = "../lighthouse_metrics" }
+lazy_static = "1.4.0"

eth2/utils/logging/src/lib.rs

@@ -1,7 +1,24 @@
+#[macro_use]
+extern crate lazy_static;
+
+use lighthouse_metrics::{
+    inc_counter, try_create_int_counter, IntCounter, Result as MetricsResult,
+};
 use std::io::{Result, Write};
 
 pub const MAX_MESSAGE_WIDTH: usize = 40;
 
+lazy_static! {
+    pub static ref INFOS_TOTAL: MetricsResult<IntCounter> =
+        try_create_int_counter("info_total", "Count of infos logged");
+    pub static ref WARNS_TOTAL: MetricsResult<IntCounter> =
+        try_create_int_counter("warn_total", "Count of warns logged");
+    pub static ref ERRORS_TOTAL: MetricsResult<IntCounter> =
+        try_create_int_counter("error_total", "Count of errors logged");
+    pub static ref CRITS_TOTAL: MetricsResult<IntCounter> =
+        try_create_int_counter("crit_total", "Count of crits logged");
+}
+
 pub struct AlignedTermDecorator {
     wrapped: slog_term::TermDecorator,
     message_width: usize,
@@ -19,14 +36,22 @@ impl AlignedTermDecorator {
 impl slog_term::Decorator for AlignedTermDecorator {
     fn with_record<F>(
         &self,
-        _record: &slog::Record,
+        record: &slog::Record,
         _logger_values: &slog::OwnedKVList,
         f: F,
     ) -> Result<()>
     where
         F: FnOnce(&mut dyn slog_term::RecordDecorator) -> std::io::Result<()>,
     {
-        self.wrapped.with_record(_record, _logger_values, |deco| {
+        match record.level() {
+            slog::Level::Info => inc_counter(&INFOS_TOTAL),
+            slog::Level::Warning => inc_counter(&WARNS_TOTAL),
+            slog::Level::Error => inc_counter(&ERRORS_TOTAL),
+            slog::Level::Critical => inc_counter(&CRITS_TOTAL),
+            _ => (),
+        }
+
+        self.wrapped.with_record(record, _logger_values, |deco| {
             f(&mut AlignedRecordDecorator::new(deco, self.message_width))
         })
     }