Helm chart. I cannot send a command to the container via --set

Question

In deployment.yaml in:

      containers:
        - name: {{ .Values.stand }}-container
          securityContext:
            {{- toYaml .Values.securityContext | nindent 12 }}
          image: "{{ .Values.image.repository }}:{{ .Values.image.tag | default .Chart.AppVersion }}"
          {{- if $.Values.command }}
          command:
            {{ .Values.command.cmd }}
          {{- end }}
          {{- if or $.Values.env $.Values.envSecrets }}

I tried adding:

{{- if $.Values.command }}
command:
  {{ .Values.command.cmd }}
{{- end }}

Then I tried to pass the command:

helm install NAME nexus/stand 
      --set 'command.cmd[0]=- /bin/sh' \
      --set 'command.cmd[1]=- -с' \
      --set 'command.cmd[2]=- |' \
      --set 'command.cmd[3]=while true; do' \
      --set 'command.cmd[4]=sleep 60;' \
      --set 'command.cmd[5]=done'

but nothing works.

How to via --set pass?

command:
- /bin/sh
- -c
- |
  while true; do
    sleep 60;
  done

Thank you.

Answer 1

Helm does not support setting non-existent array elements, you can assign values by passing the entire array or set the corresponding number of elements first, and then modify it by --set cmd[i]=xxx.

---

First of all, in the deployment.yaml file, the Values.command.cmd field should not be quoted directly, as an array needs to be quoted in the following way: {{ toYaml … }}

deployment.yaml

      containers:
        - name: {{ .Values.stand }}-container
          securityContext:
            {{- toYaml .Values.securityContext | nindent 12 }}
          image: "{{ .Values.image.repository }}:{{ .Values.image.tag | default .Chart.AppVersion }}"
          {{- if $.Values.command }}
          command:
            {{ toYaml .Values.command.cmd | nindent 12 }}
          {{- end }}
          {{- if or $.Values.env $.Values.envSecrets }}

Then if you use the values.yaml file method to pass in the parameters, you should write like this here：

values.yaml

command:
  cmd:
    - /bin/sh
    - -c
    - while true; do sleep 60; done

Finally, if you want to set by --set, you need to pass array values you can use curly braces (unix shell require quotes):

--set command.cmd={"/bin/sh"\,"-c"\,"while true; do sleep 60; done"}

Notice!!!

The separator of the array elements , you must remember to add a \