feat(sentry): introduce setting to configure traces sample rate

see also cal-itp/benefits#1360

eligibility_server/sentry.py

@@ -29,6 +29,17 @@ def get_denylist():
     return denylist
 
 
+def get_traces_sample_rate(config: Configuration):
+    rate = config.sentry_traces_sample_rate
+    if rate < 0.0 or rate > 1.0:
+        logger.warning("SENTRY_TRACES_SAMPLE_RATE was not in the range [0.0, 1.0], defaulting to 0.0")
+        rate = 0.0
+    else:
+        logger.info(f"SENTRY_TRACES_SAMPLE_RATE set to: {rate}")
+
+    return rate
+
+
 def configure(config: Configuration):
     SENTRY_DSN = config.sentry_dsn
     if SENTRY_DSN:
@@ -40,7 +51,7 @@ def configure(config: Configuration):
             integrations=[
                 FlaskIntegration(),
             ],
-            traces_sample_rate=1.0,
+            traces_sample_rate=get_traces_sample_rate(config),
             environment=SENTRY_ENVIRONMENT,
             release=release,
             in_app_include=["eligibility_server"],

eligibility_server/settings.py

@@ -46,6 +46,7 @@
 # Sentry
 
 SENTRY_DSN = None
+SENTRY_TRACES_SAMPLE_RATE = 0.0
 
 
 class Configuration:
@@ -145,3 +146,7 @@ def csv_quotechar(self):
     def sentry_dsn(self):
         sentry_dsn = current_app.config["SENTRY_DSN"]
         return str(sentry_dsn) if sentry_dsn else None
+
+    @property
+    def sentry_traces_sample_rate(self):
+        return float(current_app.config["SENTRY_TRACES_SAMPLE_RATE"])