Add metrics events for incoming emails

This lets us track how many incoming emails a GitLab instance is processing, by
email type (handler) and by project (where applicable).

2 files changed, 8 insertions, 0 deletions

diff --git a/changelogs/unreleased/add-email-receiver-metrics.yml b/changelogs/unreleased/add-email-receiver-metrics.yml
new file mode 100644
index 00000000000..53155651080
--- /dev/null
+++ b/changelogs/unreleased/add-email-receiver-metrics.yml
@@ -0,0 +1,4 @@
+---
+title: Add metrics events for incoming emails
+merge_request:
+author:
diff --git a/lib/gitlab/email/receiver.rb b/lib/gitlab/email/receiver.rb
index ec0529b5a4b..bb4fdd1f1f4 100644
--- a/lib/gitlab/email/receiver.rb
+++ b/lib/gitlab/email/receiver.rb
@@ -32,6 +32,10 @@ module Gitlab
 
         raise UnknownIncomingEmail unless handler
 
+        Gitlab::Metrics.add_event(:receive_email,
+                                  project: handler.try(:project),
+                                  handler: handler.class.name)
+
         handler.execute
       end