utils: log Sentry initialization (#11077)

## Problem

We don't have any logging for Sentry initialization. This makes it hard
to verify that it has been configured correctly.

## Summary of changes

Log some basic info when Sentry has been initialized, but omit the
public key (which allows submitting events). Also log when `SENTRY_DSN`
isn't specified at all, and when it fails to initialize (which is
supposed to panic, but we may as well).

libs/utils/src/sentry_init.rs

@@ -3,20 +3,24 @@ use std::env;
 
 use sentry::ClientInitGuard;
 pub use sentry::release_name;
+use tracing::{error, info};
 
 #[must_use]
 pub fn init_sentry(
     release_name: Option<Cow<'static, str>>,
     extra_options: &[(&str, &str)],
 ) -> Option<ClientInitGuard> {
-    let dsn = env::var("SENTRY_DSN").ok()?;
+    let Ok(dsn) = env::var("SENTRY_DSN") else {
+        info!("not initializing Sentry, no SENTRY_DSN given");
+        return None;
+    };
     let environment = env::var("SENTRY_ENVIRONMENT").unwrap_or_else(|_| "development".into());
 
     let guard = sentry::init((
         dsn,
         sentry::ClientOptions {
-            release: release_name,
-            environment: Some(environment.into()),
+            release: release_name.clone(),
+            environment: Some(environment.clone().into()),
             ..Default::default()
         },
     ));
@@ -25,5 +29,19 @@ pub fn init_sentry(
             scope.set_extra(key, value.into());
         }
     });
+
+    if let Some(dsn) = guard.dsn() {
+        info!(
+            "initialized Sentry for project {}, environment {}, release {} (using API {})",
+            dsn.project_id(),
+            environment,
+            release_name.unwrap_or(Cow::Borrowed("None")),
+            dsn.envelope_api_url(),
+        );
+    } else {
+        // This should panic during sentry::init(), but we may as well cover it.
+        error!("failed to initialize Sentry, invalid DSN");
+    }
+
     Some(guard)
 }