Update Sentry to ignore health check transactions

config/initializers/sentry.rb

@@ -7,5 +7,33 @@ Sentry.init do |config|
   # Set tracesSampleRate to 1.0 to capture 100%
   # of transactions for performance monitoring.
   # We recommend adjusting this value in production
-  config.traces_sample_rate = 0.01
+  config.traces_sampler = lambda do |sampling_context|
+    # if this is the continuation of a trace, just use that decision (rate controlled by the caller)
+    unless sampling_context[:parent_sampled].nil?
+      next sampling_context[:parent_sampled]
+    end
+
+    # transaction_context is the transaction object in hash form
+    # keep in mind that sampling happens right after the transaction is initialized
+    # for example, at the beginning of the request
+    transaction_context = sampling_context[:transaction_context]
+
+    # transaction_context helps you sample transactions with more sophistication
+    # for example, you can provide different sample rates based on the operation or name
+    op = transaction_context[:op]
+    transaction_name = transaction_context[:name]
+
+    case op
+      when /request/
+        # for Rails applications, transaction_name would be the request's path (env["PATH_INFO"]) instead of "Controller#action"
+        case transaction_name
+          when '/', '/ping'
+            0.00 # ignore health check
+          else
+            0.05
+        end
+      else
+        0.0 # ignore all other transactions
+    end
+  end
 end