helm values from kubernetes secrets?

Question

I am using this chart : https://github.com/helm/charts/tree/master/stable/prometheus-mongodb-exporter

This chart requires MONGODB_URI environment variable or mongodb.uri populated in values.yaml file, Since this is a connection string I don't want to check-in that into git. I was thinking of kubernetes secrets and provide the connection string from kubernetes secrets. I have not been able to successfully find a solution for this one.

I also tried creating another helm chart and using this one as a dependency for that chart and provide value for MONGODB_URI from secrets.yaml but that also didn't work because in prometheus-mongodb-exporter chart MONGODB_URI is defined as a required value which is then passed into secrets.yaml file within that chart, so dependency chart never gets installed because of that.

What would be the best way of achieving this?

Solution

Solution 1: Create custom chart

---

1. Delete the secret.yaml from chart's template directory.
2. Create the k8s secret on your own, maybe named cumstom-secret
3. Edit the deployment.yaml: here

       - name: MONGODB_URI
         valueFrom:
           secretKeyRef:
             name: custom-secret ## {{ include "prometheus-mongodb-exporter.fullname" . }}##
             key: mongodb-uri

---

Solution 2: Use original chart

---

1. Set a dummy value for mongodb.uri in value.yaml.
2. Use --set flag to overwrite the dummy value with original while installing the chart. So, your git won't have the history.

$ helm install prometheus-mongodb-exporter stable/prometheus-mongodb-exporter --set mongodb.uri=******

Comments

[Asav Patel]

so I have to copy original chart when creating custom chart? it's not possible to create a custom chart with original chart added as dependency?

[Kamol Hasan]

@AsavPatel no, by custom chart I meant, copy the chart some directory, edit it. And then deploy it from there. Just go to the chart directory and use helm install <name> <chart-name> . No need use repo name like stable.

[wtrocki]

Side note. Set command will store values in config-map instead of secret.