Kubernetes - Passing in environment variable and service name (from DNS) - kubernetes

Question

I can't seem to find an example of the correct syntax for inserting a environment variable along with the service name:
So I have a service defined as:
apiVersion: v1
kind: Service
metadata:
name: test
spec:
type: NodePort
ports:
- name: http
port: 3000
targetPort: 3000
selector:
app: test
I then use a secrets file with the following:
apiVersion: v1
kind: Secret
metadata:
name: test
labels:
app: test
data:
password: fxxxxxxxxxxxxxxx787xx==
And just to confirm I'm using envFrom to set that password as an env variable:
apiVersion: v1
kind: Deployment
metadata:
name: test
spec:
replicas: 1
template:
metadata:
labels:
app: test
spec:
containers:
- name: test
image: xxxxxxxxxxx
imagePullPolicy: Always
envFrom:
- configMapRef:
name: test
- secretRef:
name: test
ports:
- containerPort: 3000
Now in my config file I want to refer to that password as well as the service name itself - is this the correct way to do so:
apiVersion: v1
kind: ConfigMap
metadata:
name: test
labels:
app: test
data:
WORKING_URI: "http://somedomain:${password}#test"

Answer 1

The yaml configuration does not work the way you provided as an example.
If you want to setup Kubernetes with a complex configuration and
use variables or dynamic assignment to some of them, you have to
use an external parser to replace variable place holders. I use
bash and sed to accomplish it. I changed your config a bit:
apiVersion: v1
kind: ConfigMap
metadata:
name: test
labels:
app: test
data:
WORKING_URI: "http://somedomain:VAR_PASSWORD#test"
After saving, I created a simple shell script containing desired values.
#!/bin/sh
export PASSWORD="verysecretpwd"
cat deploy.yaml | sed "s/VAR_PASSWORD/$PASSWORD/g" | kubectl -f -