DevOps Classroom notes 12/Jan/2026

Config Maps

• Lets try to write a mysql pod

---
apiVersion: v1
kind: Pod
metadata:
  name: mysql-pod
  labels:
    app: mysql
spec:
  containers:
    - name: mysql
      image: mysql:5.7
      env:
        - name: MYSQL_ROOT_PASSWORD
          value: admin123
        - name: MYSQL_DATABASE
          value: mydb
        - name: MYSQL_USER
          value: myuser
        - name: MYSQL_PASSWORD
          value: mypassword
      ports:
        - containerPort: 3306

• Ideally configuration values should be dealt seperately for this k8s gives
  • configMaps: Non confidentail data
  • secrets: confidential data

example mysql-configuration

• cm

---
apiVersion: v1
kind: ConfigMap
metadata:
  name: mysql-cm
data:
  MYSQL_ROOT_PASSWORD: admin123
  MYSQL_DATABASE: mydb
  MYSQL_USER: myuser
  MYSQL_PASSWORD: mypassword

• pod

---
apiVersion: v1
kind: Pod
metadata:
  name: mysql-pod
  labels:
    app: mysql
spec:
  containers:
    - name: mysql
      image: mysql:5.7
      envFrom:
        - configMapRef: 
            name: mysql-cm
      ports:
        - containerPort: 3306

• config map values injected as environmental varaibles while the pod is getting created and will not automatically update with in same pod if you change config map post pod creation.
• secrets encode the plain text
• secret

---
apiVersion: v1
kind: Secret
metadata:
  name: mysql-secret
data:
  MYSQL_ROOT_PASSWORD: YWRtaW4xMjM=
  MYSQL_DATABASE: bXlkYg==
  MYSQL_USER: bXl1c2Vy
  MYSQL_PASSWORD: bXlwYXNzd29yZA==

• mysql-pod

---
apiVersion: v1
kind: Pod
metadata:
  name: mysql-pod
  labels:
    app: mysql
spec:
  containers:
    - name: mysql
      image: mysql:5.7
      envFrom:
        - secretRef: 
            name: mysql-secret
      ports:
        - containerPort: 3306