How can we specify dependency configuration values when creating a Helm application chart?

Question

I'm creating a Chart for a web application that requires a Postgres database. As I understood dependencies are references to other charts that will be installed along with the one you define, e.g.:

# Chart.yaml
dependencies:
- name: bitnami/postgresql
  version: "8.10.5"
  repository: "https://charts.bitnami.com/bitnami"

My question is how can you specify the configuration properties (--set, or values.yaml file) needed not only in your application but also for each of the dependencies?

Answer 1

First of all, you should use name: postgresql and not name: bitnami/postgresql because charts are usually not prefixed.

Error: bitnami/postgresql chart not found in repo https://charts.bitnami.com/bitnami

You can override subcharts values putting them under chart name (in your case postgresql) in values.yaml

postgresql:
  postgresqlDataDir: /data/postgresql

Or with --set postgresql.postgresqlDataDir=/data/postgresql

More info in Subcharts and globals