fix(config) Add traces_sample_rate config (#95)

* fix(config) Add traces_sample_rate config

We need a traces_sample_rate in order to collect tracing data.
With this change made I was able to validate that tracing data is being
collected and sent to sentry.

* clippy

Author: markstory

src/config.rs

@@ -19,6 +19,9 @@ pub struct Config {
     /// The environment to report to sentry errors to.
     pub sentry_env: Option<Cow<'static, str>>,
 
+    /// The sampling rate for tracing data.
+    pub traces_sample_rate: Option<f32>,
+
     /// The log level to filter logging to.
     pub log_level: LogLevel,
 
@@ -88,6 +91,7 @@ impl Default for Config {
         Self {
             sentry_dsn: None,
             sentry_env: None,
+            traces_sample_rate: Some(0.0),
             log_level: LogLevel::Debug,
             log_format: LogFormat::Text,
             grpc_addr: "0.0.0.0".to_owned(),

src/logging.rs

@@ -56,13 +56,17 @@ pub enum LogFormat {
     Text,
 }
 
+#[derive(Debug)]
 pub struct LoggingConfig {
     /// The sentry DSN to use for error reporting.
     pub sentry_dsn: Option<String>,
 
     /// The environment to report to sentry errors to.
     pub sentry_env: Option<Cow<'static, str>>,
 
+    /// The tracing sample rate
+    pub traces_sample_rate: f32,
+
     /// The log level to filter logging to.
     pub log_level: LogLevel,
 
@@ -75,6 +79,7 @@ impl LoggingConfig {
         LoggingConfig {
             sentry_dsn: config.sentry_dsn.clone(),
             sentry_env: config.sentry_env.clone(),
+            traces_sample_rate: config.traces_sample_rate.unwrap_or(0.0),
             log_level: config.log_level,
             log_format: config.log_format,
         }
@@ -89,6 +94,7 @@ pub fn init(log_config: LoggingConfig) {
             dsn,
             release: Some(Cow::Borrowed(get_version())),
             environment: log_config.sentry_env.clone(),
+            traces_sample_rate: log_config.traces_sample_rate,
             ..Default::default()
         });