Docker how to use boolean value on spec.container.env.value - docker

Question

Is there a way to pass a boolean value for spec.container.env.value ?
I want to override, with helm, a boolean env variables in a docker parent image (https://github.com/APSL/docker-thumbor) : UPLOAD_ENABLED
I made a simpler test
If you try the following yaml :
apiVersion: v1
kind: Pod
metadata:
name: envar-demo
labels:
purpose: demonstrate-envars
spec:
containers:
- name: envar-demo-container
image: gcr.io/google-samples/node-hello:1.0
env:
- name: DEMO_GREETING
value: true
And try to create it with kubernetes, you got the following error :
kubectl create -f envars.yaml
the error :
error: error validating "envars.yaml": error validating data: expected type string, for field spec.containers[0].env[0].value, got bool; if you choose to ignore these errors, turn validation off with --validate=false
with validate=false
Error from server (BadRequest): error when creating "envars.yaml": Pod in version "v1" cannot be handled as a Pod: [pos 192]: json: expect char '"' but got char 't'
It doesn't work with integer values too

Answer 1

spec.container.env.value is defined as string. see here:
https://kubernetes.io/docs/api-reference/v1.6/#envvar-v1-core
You'd have to cast/convert/coerse to boolean in your container when using this value

Answer 2

Try escaping the value. The below worked for me:
- name: DEMO_GREETING
value: "'true'"

Answer 3

This works for me.
In my example, one is hardcoded, and the other comes from an env var.
env:
- name: MY_BOOLEAN
value: 'true'
- name: MY_BOOLEAN2
value: '${MY_BOOLEAN2_ENV_VAR}'
So basically, I wrap single quotes around everything, just in case.
WARNING: Dont use hyphens in your env var names, that will not work...

Answer 4

if you are the helm chart implementer, just quote it
data:
# VNC_ONLY: {{ .Values.vncOnly }} <-- Wrong
VNC_ONLY: "{{ .Values.vncOnly }}" # <-- Correct

Answer 5

From command line you can also use
--set-string
instead of
--set
and you will be able to pass value without escaping
for instance:
--set-string "env.my-setting=False"