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kubectl create secret

Learn to create a Secret with kubectl create secret.

kubectl create secret

kubectl create secret has three subcommands: generic, tls and docker-registry. Values can also be read from files; that way passwords don't end up in the shell history:

kubectl create secret generic db-gizli --from-file=DB_PASSWORD=./parola.txt
kubectl create secret generic api-anahtar --from-env-file=gizli.env
kubectl create secret generic db-gizli --from-literal=DB_PASSWORD="$DB_PAROLA"

Rotating a Secret

When a password changes, the Secret is updated and the application is restarted to read the new value. As with ConfigMaps, the --dry-run=client -o yaml | kubectl apply -f - pattern is used:

kubectl create secret generic db-gizli --from-literal=DB_PASSWORD="$YENI_PAROLA" \
  --dry-run=client -o yaml | kubectl apply -f -
kubectl rollout restart deployment/api

kubectl describe doesn't show Secret values; it only prints their byte sizes.

Practice Rotate the password

Write two commands: generate the generic db-gizli Secret with the DB_PASSWORD key, using the value in the $YENI_PAROLA variable, as YAML without creating it, and pipe it into kubectl apply -f -; restart the api deployment.

Starter code

terminal
# buraya yaz

Sample solution

terminal
kubectl create secret generic db-gizli --from-literal=DB_PASSWORD="$YENI_PAROLA" --dry-run=client -o yaml | kubectl apply -f -
kubectl rollout restart deployment/api

Expected output

secret/db-gizli configured
deployment.apps/api restarted

Questions and answers

Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.

1 What is the drawback of writing --from-literal=DB_PASSWORD=gizli123?

  • The command doesn't work
  • The Secret type is wrong
  • The password is saved in the shell history Correct answer
  • The value isn't encrypted

Explanation: Reading from a file or an environment variable is safer.

2 Read the value from a file.

Question 
kubectl create secret generic db-gizli ____=DB_PASSWORD=./parola.txt
Answer 
kubectl create secret generic db-gizli --from-file=DB_PASSWORD=./parola.txt

Explanation: --from-file=key=path sets the key name.

3 Match.

Term Meaning
generic Generic Secret
tls Certificate
docker-registry Registry login
describe secret Shows only sizes

All lessons in Intermediate

1 What is Kubernetes?

  1. What is Kubernetes?
  2. Why Kubernetes?
  3. Cluster architecture
  4. Control plane
  5. Worker node
  6. Summary - What is Kubernetes

2 Minikube

  1. What is Minikube?
  2. Installing Minikube
  3. minikube start
  4. minikube status
  5. minikube dashboard
  6. Summary - Minikube

3 kubectl basics

  1. What is kubectl?
  2. kubectl get
  3. kubectl describe
  4. kubectl apply
  5. kubectl delete
  6. Summary - kubectl

4 Pod

  1. What is a Pod?
  2. Pod YAML
  3. Creating a Pod
  4. Pod status
  5. Multi-container Pod
  6. Summary - Pod

5 Deployment

  1. What is a Deployment?
  2. Deployment YAML
  3. Replica count
  4. Rolling update
  5. Rollback
  6. Summary - Deployment

6 ReplicaSet

  1. What is a ReplicaSet?
  2. ReplicaSet YAML
  3. ReplicaSet selector
  4. Scaling
  5. Self-healing
  6. Summary - ReplicaSet

7 Service

  1. What is a Service?
  2. ClusterIP
  3. NodePort
  4. LoadBalancer
  5. Service selector
  6. Summary - Service

8 ConfigMap

  1. What is a ConfigMap?
  2. ConfigMap YAML
  3. Environment variable
  4. Mounting as a volume
  5. kubectl create configmap
  6. Summary - ConfigMap

9 Secret

  1. What is a Secret?
  2. Secret types
  3. Secret YAML
  4. Mounting a Secret
  5. kubectl create secret
  6. Summary - Secret

10 Namespace

  1. What is a Namespace?
  2. kubectl get namespaces
  3. Creating a Namespace
  4. The -n flag
  5. Default Namespace
  6. Summary - Namespace

11 Labels and selectors

  1. What is a label?
  2. Adding labels
  3. Label selector
  4. kubectl get -l
  5. Equality and set selectors
  6. Summary - Labels

12 Project: Multi-tier app

  1. Project design
  2. Database Deployment
  3. Web Deployment
  4. ConfigMap and Secret
  5. Putting it together - multi-tier

13 Troubleshooting

  1. kubectl logs
  2. kubectl exec
  3. kubectl describe pod
  4. CrashLoopBackOff
  5. Pending Pod
  6. Summary - Troubleshooting

14 Intermediate final

  1. Challenge - Pod YAML
  2. Challenge - Deployment
  3. Challenge - Service
  4. Challenge - ConfigMap
  5. Challenge - Intermediate project