Add envfrom parameters

[Elbandi]

What this PR does / why we need it:

Allow extra environment variables from secrets or configmaps.

(my usecase: added custom userparameters, which use some passwords. This password can set from secrets with env)

Special notes for your reviewer:

I hesitated the right variable name (envFrom vs extraEnvFrom). i checked some other helm charts, and more use envFrom names.
like traefik, filebeat (with extraEnvs and extraVolumes).

Checklist

[Place an '[x]' (no spaces) in all applicable fields. Please remove unrelated fields.]

• DCO signed
• Chart Version bumped
• Variables are documented in the README.md

[aeciopires]

Hey @Elbandi!
Thank you for your contribution.
But I think extraEnv can be refactored to add support for the same functionality as envFrom. This avoids confusion for users of helm charts.

What do you think? Could you make this change or can I make it?

The final solution is to change each template file:

before (example):

           {{- range $item := .Values.zabbixServer.extraEnv }}
            - name: {{ $item.name }}
              value: {{ $item.value | quote }}
            {{- end }}

after (example):

            {{- with .Values.zabbixServer.extraEnv }}
              {{- toYaml . | nindent 12 }}
            {{- end }}

The final values (example) can be:

  extraEnv:
    - name: "ZBX_EXAMPLE_MY_ENV_1"
      value: "true"
    - name: "ZBX_EXAMPLE_MY_ENV_2"
      value: "false"
    - name: "ZBX_EXAMPLE_MY_ENV_3"
      value: "100"
    - name: MY_USERNAME
      valueFrom:
        secretKeyRef:
          name: my-envs
          key: user
    - name: MY_PASSWORD
      valueFrom:
        secretKeyRef:
          name: my-envs
          key: password      

Did you understand the suggestion?

[aeciopires]

Hi @Elbandi!

I launched the version 4.4.1. See:

• https://github.com/zabbix-community/helm-zabbix/releases/tag/zabbix-4.4.1
• Improvements in services templates of Zabbix components #95

Please sync this changes in your local branch

[aeciopires]

Hello @Elbandi!

I published a new chart version to support Zabbix 7.0 and added the improvements suggested in this PR, but I keep your credits related the idea and implementation.

More details: #96

I will close this PR to avoid code conflicts

Thanks for your contribution.