Catch error during maintenance window request (#19482)

config/settings.yml

@@ -838,7 +838,7 @@ maintenance:
     carma: P6XLE0T
     appeals: P9S4RFU
     arcgis: P45YBFA
-    coe: PXXXXXX
+    coe: PSY4HU1
     dslogon: P9DJJAV
     es: PH7OPR4
     evss: PZKWB6Y

lib/pagerduty/maintenance_client.rb

@@ -19,6 +19,8 @@ def get_all(options = {})
 
     def get_all_raw(options = {})
       resp = get_raw(options)
+      return [] if resp.nil?
+
       windows = resp['maintenance_windows']
       while resp['more']
         offset = resp['offset'] + resp['limit']
@@ -34,7 +36,19 @@ def get_raw(options = {})
         'filter' => 'open',
         'service_ids' => PagerDuty::Configuration.service_ids
       }.merge(options)
-      perform(:get, 'maintenance_windows', query).body
+
+      begin
+        perform(:get, 'maintenance_windows', query).body
+      rescue => e
+        if e&.original_status == 400
+          Rails.logger.error(
+            "Invalid arguments sent to PagerDuty. One of the following Service IDs is bad: #{query['service_ids']}"
+          )
+        else
+          Rails.logger.error("Querying PagerDuty for maintenance windows failed with the error: #{e.message}")
+        end
+        nil
+      end
     end
 
     def convert(raw_mws)

spec/lib/pagerduty/maintenance_client_spec.rb

@@ -82,6 +82,40 @@
     end
   end
 
+  context 'with bad requests' do
+    before { allow(Settings.maintenance).to receive(:services).and_return({ evss: 'XBADXX' }) }
+
+    it 'returns empty results and error with bad service IDs' do
+      stub_request(:get, 'https://api.pagerduty.com/maintenance_windows')
+        .with(query: hash_including('service_ids' => %w[XBADXX], 'offset' => '0'))
+        .to_return(
+          status: 400
+        )
+
+      expect(Rails.logger).to receive(:error)
+        .with('Invalid arguments sent to PagerDuty. One of the following Service IDs is bad: ["XBADXX"]')
+
+      windows = subject.get_all
+      expect(windows).to be_empty
+    end
+
+    it 'returns empty results and custom error message on 429 error' do
+      stub_request(:get, 'https://api.pagerduty.com/maintenance_windows')
+        .with(query: hash_including('service_ids' => %w[XBADXX], 'offset' => '0'))
+        .to_return(
+          status: 429
+        )
+
+      # rubocop:disable Layout/LineLength
+      error_message = 'Querying PagerDuty for maintenance windows failed with the error: BackendServiceException: {:status=>429, :detail=>nil, :code=>"PAGERDUTY_429", :source=>nil}'
+      # rubocop:enable Layout/LineLength
+      expect(Rails.logger).to receive(:error).with(error_message)
+
+      windows = subject.get_all
+      expect(windows).to be_empty
+    end
+  end
+
   context 'with options specified' do
     let(:body) { File.read('spec/support/pagerduty/maintenance_windows_simple.json') }