Failure when using mariadb since 2.9.0

[roelofjansen]

I cannot update to 2.9.0. I use the mariadb subchart and noticed it was updated. I changed my values.yaml accordingly but I get the following error;

Error: template: nextcloud/charts/nextcloud/templates/deployment.yaml:75:66: executing "nextcloud/charts/nextcloud/templates/deployment.yaml" at <.Subcharts.mariadb>: nil pointer evaluating interface {}.mariadb

The error is caused by;
value: {{ template "mariadb.primary.fullname" .Subcharts.mariadb }}

The .Subcharts.mariadb was not there in 2.8.x. If I remove this directive, everything works fine again.

Can you please fix the error or otherwise explain how to use the new format?

Kind regards,
Roelof

[ariep]

What version of helm are you using? You need a very recent helm, at least 3.7, to provide the .Subcharts values.

[roelofjansen]

Hi, I use the latest Argo-cd V2.1.6 which in turn uses helm 3.6.0 which is from June 2021. Kind regards, Roelof.

[eweinell]

unless it is really worthwile, I would favor not using features from Helm versions that young. I didn't come accross this variable, and tbh don't see why it is required here. (I'm also using argo and cannot upgrade helm easily)

[ariep]

Well, I'm obviously biased as the one who introduced this usage of .Subcharts to this chart, but I think it's really worthwhile.

To provide a little bit of context: nextcloud has mariadb as a dependency chart. The nextcloud chart itself needs to know the mariadb service name, so it can use that as the hostname of the database server to talk to. The mariadb service name is calculated by a helm template function inside the mariadb chart. So at the point of the nextcloud chart where you need to set the database host, you would like to call that template function but with all substitutions done from the mariadb chart, otherwise the two calculated names do not match up. Until the introduction of the .Subcharts variable, such a call with "subchart context" was not possible. What everyone did instead, was copying the definition of the mariadb service name template function into the nextcloud chart, and hope for the best. This is obviously brittle in the face of changes, but works most of the time.

On top of that, recently mariadb started using the bitnami common library chart to factor out parts that are common to many of the bitnami charts. This introduced a dependency of mariadb, which itself is already a dependency of nextcloud. As you can guess the service name template function is part of the common library chart. At this point it became even messier to copy and combine the relevant definitions from both mariadb and common, and I was very happy to be able to use the principled solution of the .Subcharts variable that's now available.

I understand the inconvenience of your tool not being updated to include a more recent helm version. I would hope and expect that it will be updated soon though. As comparison, we use fluxcd which already includes a new enough helm for some time.

[varac]

The upgrade to helm 3.7.1 in argo-cd got merged 6 days ago, so it will be in the next release. I'd propose to describe the current situation at argo-cd, and ask them for a next release which profits from helm 3.7.

[mikeyGlitz]

What version of helm are you using? You need a very recent helm, at least 3.7, to provide the .Subcharts values.

I have helm v3.7.1 installed and am encountering this issue.

Is there a way to verify using the Terraform helm provider?

[sathieu]

You can try ghcr.io/argoproj/argocd:2.2.0-dc243800 or later which has helm 3.7.1.

[roelofjansen]

Hi,

I added the following below the repoServer section of my argocd helm chart's values.yaml to update to Helm 3.7.1 and now the .Subcharts.mariadb part is handled correctly.

This is explained in more detail in: https://github.com/argoproj/argo-cd/blob/master/docs/operator-manual/custom_tools.md

  repoServer:
    name: repo-server

    volumes:
    - name: custom-tools
      emptyDir: {}

    initContainers:
    - name: download-helm3
      image: alpine:3.12
      command: [sh, -c]
      args:
        - wget -qO- https://get.helm.sh/helm-v3.7.1-linux-amd64.tar.gz | tar -xvzf - &&
          mv linux-amd64/helm /custom-tools/
      volumeMounts:
        - mountPath: /custom-tools
          name: custom-tools
    volumeMounts:
    - mountPath: /usr/local/bin/helm
      name: custom-tools
      subPath: helm

P.s. maybe you should note the Helm 3.7.x dependency somewhere in your Chart.yaml!

[ishioni]

I just got hit with this while using newest fluxcd. According to flux devs they'll be stuck on 3.6.3 for a while