Add project_remote_mirror_last_successful_update_time_seconds metric

Gemfile.lock

 PATH
   remote: .
   specs:
-    gitlab-monitor (3.6.0)
+    gitlab-monitor (3.7.0)
       connection_pool (~> 2.2.1)
       pg (~> 1.1)
       quantile (~> 0.2.0)

README.md

@@ -28,7 +28,7 @@ metrics.
       `gitlab_database_bloat_$type_$key` with type `btree` (index bloat) or `table`
       (table bloat) and keys `bloat_ratio bloat_size extra_size real_size` (see below)
     * [Remote mirrors](lib/gitlab_monitor/database/remote_mirrors.rb) --
-      `project_remote_mirror_last_successful_update_time_seconds`
+      `project_remote_mirror_last_successful_update_time_seconds`, `project_remote_mirror_last_update_time_seconds`
 1. Git
     * [git pull/push timings](lib/gitlab_monitor/git.rb) --
       `git_pull_time_milliseconds`, `git_push_time_milliseconds`

lib/gitlab_monitor/database/remote_mirrors.rb

@@ -4,7 +4,9 @@ module GitLab
       # A helper class to collect remote mirrors metrics.
       class RemoteMirrorsCollector < Base
         QUERY = <<~SQL.freeze
-          SELECT project_id, url, EXTRACT(EPOCH FROM last_successful_update_at) AS last_successful_update_at
+          SELECT project_id, url,
+          EXTRACT(EPOCH FROM last_successful_update_at) AS last_successful_update_at,
+          EXTRACT(EPOCH FROM last_update_at) AS last_update_at
           FROM remote_mirrors WHERE project_id IN (%s) AND enabled = 't'
         SQL
 
@@ -41,14 +43,18 @@ module GitLab
           )
         end
 
-        def probe_db
+        def probe_db # rubocop:disable Metrics/MethodLength
           results = @collector.run
           results.to_a.each do |row|
-            last_successful_update_at = row.delete("last_successful_update_at").to_i
-
             @metrics.add(
               "project_remote_mirror_last_successful_update_time_seconds",
-              last_successful_update_at,
+              row["last_successful_update_at"].to_i,
+              project_id: row["project_id"],
+              url: row["url"]
+            )
+            @metrics.add(
+              "project_remote_mirror_last_update_time_seconds",
+              row["last_update_at"].to_i,
               project_id: row["project_id"],
               url: row["url"]
             )

lib/gitlab_monitor/version.rb

 module GitLab
   module Monitor
-    VERSION = "3.6.0".freeze
+    VERSION = "3.7.0".freeze
   end
 end