How to create an environment variable in kubernetes container - kubernetes

Question

I am trying to pass an environment variable in kubernetes container.
What have I done so far ?
Create a deployment
kubectl create deployment foo --image=foo:v1
Create a NODEPORT service and expose the port
kubectl expose deployment/foo --type=NodePort --port=9000
See the pods
kubectl get pods
dump the configurations (so to add the environment variable)
kubectl get deployments -o yaml > dev/deployment.yaml
kubectl get svc -o yaml > dev/services.yaml
kubectl get pods -o yaml > dev/pods.yaml
Add env variable to the pods
env:
name: FOO_KEY
value: "Hellooooo"
Delete the svc,pods,deployments
kubectl delete -f dev/ --recursive
Apply the configuration
kubectl apply -f dev/ --recursive
Verify env parameters
kubectl describe pods
Something weird
If I manually changed the meta information of the pod yaml and hard code the name of the pod. It gets the env variable. However, this time two pods come up one with the hard coded name and other with the hash with it. For example, if the name I hardcoded was "foo", two pods namely foo and foo-12314faf (example) would appear in "kubectl get pods". Can you explain why ?
Question
Why does the verification step does not show the environment variable ?

Answer 1

As the issue is resolved in the comment section.
If you want to set env to pods I would suggust you to use set sub commend
kubectl set env --help will provide more detail such as list the env and create new one
Examples:
# Update deployment 'registry' with a new environment variable
kubectl set env deployment/registry STORAGE_DIR=/local
# List the environment variables defined on a deployments 'sample-build'
kubectl set env deployment/sample-build --list
Deployment enables declarative updates for Pods and ReplicaSets. Pods are not typically directly launched on a cluster. Instead, pods are usually managed by replicaSet which is managed by deployment.
following thread discuss what-is-the-difference-between-a-pod-and-a-deployment

Answer 2

You can add any number of env vars into your deployment file
spec:
containers:
- name: auth
image: lord/auth
env:
- name: MONGO_URI
value: "mongodb://auth-mongo-srv:27017/auth"
process.env.MONGO_URI
or you can add a secret first then use newly created secret into your countless deployment files to share same environment variable with value:
kubectl create secret generic jwt-secret --from-literal=JWT_KEY=my_awesome_jwt_secret_code
spec:
containers:
- name: auth
image: lord/auth
env:
- name: MONGO_URI
value: "mongodb://auth-mongo-srv:27017/auth"
- name: JWT_KEY
valueFrom:
secretKeyRef:
name: jwt-secret
key: JWT_KEY
process.env.MONGO_URI
process.env.JWT_KEY