[wstrange]

Helm is another great option here.

Helm uses Go templates. You define your variables in a top level values.yaml, and then install the chart to your cluster. The variables get expanded on chart install.

Here is a snippet from a deployment:

    env:
        {{- range $key, $value := .Values.my_env_vars }}
          - name: {{ $key }}
            value: {{ $value  | quote }}
        {{ end }}