fix: Improve graceful shutdown by adding a pre-stop handler in the k8s deployment (#24)

Author: bmonkman

charts/zero-notifcation-service/Chart.yaml

@@ -15,9 +15,9 @@ type: application
 # This is the chart version. This version number should be incremented each time you make changes
 # to the chart and its templates, including the app version.
 # Versions are expected to follow Semantic Versioning (https://semver.org/)
-version: 0.0.6
+version: 0.0.7
 
 # This is the version number of the application being deployed. This version number should be
 # incremented each time you make changes to the application. Versions are not expected to
 # follow Semantic Versioning. They should reflect the version the application is using.
-appVersion: 0.0.9
+appVersion: 0.0.10

charts/zero-notifcation-service/templates/deployment.yaml

@@ -51,6 +51,15 @@ spec:
             initialDelaySeconds: 5
             periodSeconds: 10
             timeoutSeconds: 2
+          # Some time before the termination signal is sent where the pod will be in a terminating statue and shouldn't receive traffic
+          # to reduce race conditions where the ingress sends a request to a service that is terminating
+          lifecycle:
+            preStop:
+              exec:
+                command:
+                - /bin/sh
+                - -c
+                - sleep 5
           resources:
             {{- toYaml .Values.resources | nindent 12 }}
           envFrom:
@@ -70,3 +79,5 @@ spec:
       tolerations:
         {{- toYaml . | nindent 8 }}
       {{- end }}
+      # Prestop from above plus supplied grace period plus a small buffer
+      terminationGracePeriodSeconds: {{ add 7 .Values.application.gracefulShutdownTimeout }}