Before I dig in further, why wouldn't the extra objects be a second chart someone installs that add those?

Consider package managers for other platforms (like Linux) installing something like PHP or ffmpeg. For the "additional" parts there are secondary packages one would install. Why wouldn't that same style experience be followed?

Before I dig in further, why wouldn't the extra objects be a second chart someone installs that add those?

My understanding is that users find it laborious to create and maintain a second chart.
They prefer the extraObjects approach because it is less effort and because it has become a familiar pattern in other charts.
All the Bitnami charts have this option, for example.

There is an example of this in traefik/traefik-helm-chart#595 (comment) and apache/couchdb-helm#72 (comment) where @colearendt wrote:

In many cases, it can avoid the need for additional (fake helm chart w/ a few resources), extended (chart that extends the traefik chart), or adhoc deployments (kubectl apply and friends).

@wallrj, you forgot to mention this: fluent/helm-charts#331 😉

I think that Helm is currently lacking documentation & conventions (and maybe some tooling) to correctly separate the various roles who interact with it; this has led to charts trending towards having fewer constraints and being less opinionated. The addition of the extraObjects pattern in public Helm charts is a prime example of this direction of travel. I think this is a case of convenience over correctness as the documented pattern for this functionality is using public charts as sub-charts with additional resources strongly typed.

This said I can see value in adding native Helm support for rendering external templates as part of a chart install. I think the wrapper chart pattern is a better solution but anything to help move away from the extraObjects pattern would be a step in the right direction.

IMHO a public Helm chart (for a component) should aim to be as opinionated as possible while following the open-closed principal.

@wallrj Also, this is related kubernetes/autoscaler#5633

Before I dig in further, why wouldn't the extra objects be a second chart someone installs that add those?

@mattfarina are you persuaded by the reasons given in the comments above?

New use case: kubernetes/ingress-nginx#11351 (Always me 😛)

This issue has been marked as stale because it has been open for 90 days with no activity. This thread will be automatically closed in 30 days if no further activity occurs.

This feature is still needed.

Another addition to the topic: kubernetes/autoscaler#7243