onechart/website/docs/examples/custom-command.md

OneChart settings for overriding the default command to run:

image:
  repository: debian
  tag: stable-slim

command: |
  while true; do date; sleep 2; done

Check the Kubernetes manifest:

cat << EOF > values.yaml
image:
  repository: debian
  tag: stable-slim

command: |
  while true; do date; sleep 2; done
EOF

helm template my-release onechart/onechart -f values.yaml

Using bash

cat << EOF > values.yaml
image:
  repository: debian
  tag: stable-slim

command: |
  while true; do date; sleep 2; done
shell: "/bin/bash"
EOF

helm template my-release onechart/onechart -f values.yaml

Running a command in Alpine Linux

cat << EOF > values.yaml
image:
  repository: alpine
  tag: 3.12

command: |
  while true; do date; sleep 2; done
shell: "/bin/ash"
EOF

helm template my-release onechart/onechart -f values.yaml