Connection to MongoDB ReplicaSet on Kubernetes

Question

I have deployed MongoDB ReplicaSet on Kubernetes using Helm and the chart stable/mongodb-replicaset

On Kubernetes, I can connect to MongoDB using the connection string which is something of the sort

mongodb://mongodb0.example.com:27017,mongodb1.example.com:27017,mongodb2.example.com:27017/?replicaSet=myRepl

In the event I change the number of replicas, the connection string would change as well, which also means that every application connecting to the database would need to be updated.

Is there a workaround to this?

I thought of creating a Service, so that only this would need to be changed, however the connection string does not pass regex validation.

Any help on this is appreciated.

Answer 1

The Helm chart stable/mongodb-replicaset deploys also 2 headless services:

1. <release name>-mongodb-replicaset
2. <release name>-mongodb-replicaset-client

The DNS record of <release name>-mongodb-replicaset returns the address of all the replicas, so, in order to connect to the replicaset, the connection string is

"mongodb+srv://<release name>-mongodb-replicaset.namespace.svc.cluster.local/?tls=false&ssl=false"

Note that tls and ssl have been set to false for testing as they were enabled by default.