Remove redundant postgres exporter custom queries

Postgres-exporter 13.0 moved queries from the default
queries.yaml to collectors.

The newly implemented collectors conflict with the
custom queries.yaml from Omnibus, causing errors
like:

```
An error has occurred while serving metrics:

collected metric pg_replication_is_replica gauge:{value:0} has help
"Indicates if the server is a replica" but should have "Indicates if
this host is a slave"
```

Upstream MR:
  prometheus-community/postgres_exporter#801

Closes https://gitlab.com/gitlab-org/omnibus-gitlab/-/issues/8164

Closes https://gitlab.com/gitlab-org/omnibus-gitlab/-/issues/8112

Changelog: fixed

files/gitlab-config-template/gitlab.rb.template

@@ -2287,14 +2287,16 @@ external_url 'GENERATED_EXTERNAL_URL'
 # postgres_exporter['home'] = '/var/opt/gitlab/postgres-exporter'
 # postgres_exporter['log_directory'] = '/var/log/gitlab/postgres-exporter'
 # postgres_exporter['log_group'] = nil
-# postgres_exporter['flags'] = {}
+# postgres_exporter['flags'] = {
+#  'collector.stat_user_tables' => false,
+#  'collector.postmaster' => true
+# }
 # postgres_exporter['listen_address'] = 'localhost:9187'
 # postgres_exporter['env_directory'] = '/opt/gitlab/etc/postgres-exporter/env'
 # postgres_exporter['env'] = {
 #   'SSL_CERT_DIR' => "/opt/gitlab/embedded/ssl/certs/"
 # }
 # postgres_exporter['sslmode'] = nil
-# postgres_exporter['per_table_stats'] = false
 
 ##! Service name used to register Postgres Exporter as a Consul service
 # postgres_exporter['consul_service_name'] = 'postgres-exporter'

files/gitlab-cookbooks/monitoring/attributes/default.rb

@@ -84,8 +84,12 @@
 default['monitoring']['postgres_exporter']['env'] = {
   'SSL_CERT_DIR' => "#{node['package']['install-dir']}/embedded/ssl/certs/"
 }
+default['monitoring']['postgres_exporter']['flags'] = {
+  'collector.stat_user_tables' => false,
+  'collector.postmaster' => true
+}
 default['monitoring']['postgres_exporter']['sslmode'] = nil
-default['monitoring']['postgres_exporter']['per_table_stats'] = false
+default['monitoring']['postgres_exporter']['per_table_stats'] = nil
 default['monitoring']['postgres_exporter']['consul_service_name'] = 'postgres-exporter'
 default['monitoring']['postgres_exporter']['consul_service_meta'] = nil
 

files/gitlab-cookbooks/monitoring/recipes/postgres-exporter.rb

@@ -35,7 +35,8 @@
 
 node.default['monitoring']['postgres_exporter']['env']['DATA_SOURCE_NAME'] = "#{postgres_exporter_connection_string} " \
                                                                              "database=#{postgres_exporter_database}"
-
+deprecated_per_table_stats = node['monitoring']['postgres_exporter']['per_table_stats']
+node.override['monitoring']['postgres_exporter']['flags']['collector.stat_user_tables'] = deprecated_per_table_stats unless deprecated_per_table_stats.nil?
 include_recipe 'postgresql::user'
 
 # Create log_directory

files/gitlab-cookbooks/monitoring/templates/postgres-queries.yaml.erb

@@ -1,97 +1,3 @@
-pg_replication:
-  query: "SELECT EXTRACT(EPOCH FROM (now() - pg_last_xact_replay_timestamp()))::INT as lag, CASE WHEN pg_is_in_recovery() THEN 1 ELSE 0 END as is_replica"
-  metrics:
-    - lag:
-        usage: "GAUGE"
-        description: "Replication lag behind master in seconds"
-    - is_replica:
-        usage: "GAUGE"
-        description: "Indicates if this host is a slave"
-
-pg_postmaster:
-  query: "SELECT pg_postmaster_start_time as start_time_seconds from pg_postmaster_start_time()"
-  metrics:
-    - start_time_seconds:
-        usage: "GAUGE"
-        description: "Time at which postmaster started"
-
-<% if node['monitoring']['postgres_exporter']['per_table_stats'] -%>
-pg_stat_user_tables:
-  query: |
-    SELECT
-      current_database() datname,
-      schemaname,
-      relname,
-      seq_scan,
-      seq_tup_read,
-      idx_scan,
-      idx_tup_fetch,
-      n_tup_ins,
-      n_tup_upd,
-      n_tup_del,
-      n_tup_hot_upd,
-      n_live_tup,
-      n_dead_tup,
-      GREATEST(last_autovacuum, last_vacuum, '1970-01-01Z') as last_vacuum,
-      GREATEST(last_autoanalyze, last_analyze, '1970-01-01Z') as last_analyze,
-      (vacuum_count + autovacuum_count) as vacuum_count,
-      (analyze_count + autoanalyze_count) as analyze_count
-    FROM
-      pg_stat_user_tables
-  metrics:
-    - datname:
-        usage: "LABEL"
-        description: "Name of current database"
-    - schemaname:
-        usage: "LABEL"
-        description: "Name of the schema that this table is in"
-    - relname:
-        usage: "LABEL"
-        description: "Name of this table"
-    - seq_scan:
-        usage: "COUNTER"
-        description: "Number of sequential scans initiated on this table"
-    - seq_tup_read:
-        usage: "COUNTER"
-        description: "Number of live rows fetched by sequential scans"
-    - idx_scan:
-        usage: "COUNTER"
-        description: "Number of index scans initiated on this table"
-    - idx_tup_fetch:
-        usage: "COUNTER"
-        description: "Number of live rows fetched by index scans"
-    - n_tup_ins:
-        usage: "COUNTER"
-        description: "Number of rows inserted"
-    - n_tup_upd:
-        usage: "COUNTER"
-        description: "Number of rows updated"
-    - n_tup_del:
-        usage: "COUNTER"
-        description: "Number of rows deleted"
-    - n_tup_hot_upd:
-        usage: "COUNTER"
-        description: "Number of rows HOT updated (i.e., with no separate index update required)"
-    - n_live_tup:
-        usage: "GAUGE"
-        description: "Estimated number of live rows"
-    - n_dead_tup:
-        usage: "GAUGE"
-        description: "Estimated number of dead rows"
-    - last_vacuum:
-        usage: "GAUGE"
-        description: "Last time at which this table was vacuumed (not counting VACUUM FULL)"
-    - last_analyze:
-        usage: "GAUGE"
-        description: "Last time at which this table was analyzed"
-    - vacuum_count:
-        usage: "COUNTER"
-        description: "Number of times this table has been vacuumed"
-    - analyze_count:
-        usage: "COUNTER"
-        description: "Number of times this table has been analyzed"
-
-<% end -%>
 pg_total_relation_size:
   query: |
     SELECT relnamespace::regnamespace as schemaname,

files/gitlab-cookbooks/package/libraries/deprecations.rb

@@ -337,7 +337,13 @@ def list(existing_config = nil)
             deprecation: '15.9',
             removal: '17.0',
             note: "Starting with GitLab 17.0, running Sidekiq with negate (`sidekiq['negate'] = true`) will be removed. We recommend to follow the steps at https://docs.gitlab.com/ee/administration/sidekiq/extra_sidekiq_processes.html#start-multiple-processes, to run Sidekiq with multiple processes while listening to all queues."
-          }
+          },
+          {
+            config_keys: %w(postgres_exporter per_table_stats),
+            deprecation: '16.4', # Remove message issue: https://gitlab.com/gitlab-org/omnibus-gitlab/-/issues/8170
+            removal: '17.0', # Removal issue: https://gitlab.com/gitlab-org/omnibus-gitlab/-/issues/8169
+            note: "Starting with GitLab 17.0, this directive will be controlled by `postgres_exporter['flags'] = { 'collector.stat_user_tables' => bool }`."
+          },
         ]
 
         deprecations += praefect_legacy_configuration_deprecations

spec/chef/cookbooks/monitoring/recipes/postgres_exporter_spec.rb

@@ -98,8 +98,8 @@
     it 'creates the queries.yaml file' do
       expect(chef_run).to render_file('/var/opt/gitlab/postgres-exporter/queries.yaml')
         .with_content { |content|
-          expect(content).to match(/pg_replication:/)
-          expect(content).not_to match(/pg_stat_user_table:/)
+          expect(content).to match(/pg_total_relation_size:/)
+          expect(content).to match(/pg_blocked:/)
         }
     end
 
@@ -110,6 +110,13 @@
           expect(content).to match(/extend.query-path=\/var\/opt\/gitlab\/postgres-exporter\/queries.yaml/)
         }
     end
+
+    it 'does disable user stats' do
+      expect(chef_run).to render_file('/opt/gitlab/sv/postgres-exporter/run')
+        .with_content { |content|
+          expect(content).to match(/no-collector.stat_user_tables/)
+        }
+    end
   end
 
   context 'when enabled and run as an isolated recipe' do
@@ -164,11 +171,6 @@
         .with_content(/some.flag=foo/)
     end
 
-    it 'creates the queries.yaml file' do
-      expect(chef_run).to render_file('/var/opt/gitlab/postgres-exporter/queries.yaml')
-        .with_content(/pg_stat_user_tables:/)
-    end
-
     it 'creates necessary env variable files' do
       expect(chef_run).to create_env_dir('/opt/gitlab/etc/postgres-exporter/env').with_variables(
         default_vars.merge(
@@ -180,6 +182,13 @@
         )
       )
     end
+
+    it 'does not disable user stats' do
+      expect(chef_run).to render_file('/opt/gitlab/sv/postgres-exporter/run')
+        .with_content { |content|
+          expect(content).not_to match(/no-collector.stat_user_tables/)
+        }
+    end
   end
 
   context 'log directory and runit group' do