added liveness probe commands to use mongo instead of mongosh (#91)

* added liveness probe commands to use mongo instead of mongosh as liveness probe command

* added readiness probe, and modified to custom readiness/liveness probe

* ignoring default liveness/readiness probes so that custom ones are picked up, as per the mongodb bitmani values.yaml file

helm/diffcalc-api/values.yaml

@@ -103,6 +103,34 @@ mongodb:
   persistence:
     existingClaim: diffcalc-mongo-volume
     createNew: false
+  livenessProbe:
+    enabled: false
+  readinessProbe:
+    enabled: false
+  customLivenessProbe:
+    exec:
+      command:
+        - mongo
+        - --disableImplicitSessions
+        - --eval
+        - "db.adminCommand('ping')"
+    initialDelaySeconds: 30
+    periodSeconds: 10
+    timeoutSeconds: 5
+    successThreshold: 1
+    failureThreshold: 6
+  customReadinessProbe:
+    exec:
+      command:
+        - mongo
+        - --disableImplicitSessions
+        - --eval
+        - "db.adminCommand('ping')"
+    initialDelaySeconds: 30
+    periodSeconds: 10
+    timeoutSeconds: 5
+    successThreshold: 1
+    failureThreshold: 6
 
 logging:
   level: "WARN"