Introduction to Kubernetes: Secrets

Create a cluster with Kind

kind create cluster --name secrets --image kindest/node:v1.31.1

Our Secret

We have a secret under kubernetes/secrets/secret.json

cat kubernetes/secrets/secret.json

Using our secret in a container

As a file:

docker run -it -v $PWD/kubernetes/secrets/secret.json:/secrets/secret.json ubuntu:latest bash

cat /secrets/secret.json

As environment variables:

api_key="somesecretgoeshere"
docker run -it -e API_KEY=$api_key ubuntu:latest bash

echo $API_KEY

Kubernetes Secret

Create our secret

There are two main ways we can create a Kubernetes secret.
Either by creating the secret object with kubectl create secret or apply\create it declaratively using YAML with kubectl apply -f

kubectl create secret:

kubectl create secret generic mysecret --from-file kubernetes/secrets/secret.json

kubectl apply -f or kubectl create -f allows us to define things declaratively using YAML files:

kubectl apply -f kubernetes/secrets/secret.yaml

Use our secret

In order to use our secret we add a volume to our pod spec and then mount that using a volumeMount
We can also use a secret references as env variable

kubectl apply -f kubernetes/secrets/pod.yaml