Bits of .NET

⚙️ ConfigMaps = Configuration

Hardcoding config is bad. ConfigMaps externalize configuration. Change settings without rebuilding.

📝 Creating ConfigMaps

# From literal values
kubectl create configmap app-config \
    --from-literal=env=production \
    --from-literal=log-level=debug \
    --from-literal=api-url=https://api.example.com

# From file
kubectl create configmap app-config \
    --from-file=./configs/app.properties \
    --from-file=./configs/log4j.properties

# From YAML
apiVersion: v1
kind: ConfigMap
metadata:
    name: app-config
data:
    env: production
    log-level: debug
    api-url: https://api.example.com
    app.properties: |
        database.url=postgres://localhost/db
        database.user=postgres
        cache.ttl=3600

🎯 Using ConfigMaps

# As environment variables
apiVersion: v1
kind: Pod
metadata:
    name: myapp
spec:
    containers:
    - name: app
        image: myapp:latest
        env:
        - name: ENV
            valueFrom:
                configMapKeyRef:
                    name: app-config
                    key: env
        - name: LOG_LEVEL
            valueFrom:
                configMapKeyRef:
                    name: app-config
                    key: log-level

# All env from ConfigMap
spec:
    containers:
    - name: app
        envFrom:
        - configMapRef:
            name: app-config

# As volume mount
spec:
    containers:
    - name: app
        volumeMounts:
        - name: config-volume
            mountPath: /etc/config
            readOnly: true
    volumes:
    - name: config-volume
        configMap:
            name: app-config

# ConfigMap Tips
- Separate config from code
- Use different ConfigMaps per environment
- Use subPath for specific files
- ConfigMaps update automatically (volume mounts)
- Not for sensitive data (use Secrets)

💡 ConfigMap Tips

• Separate config from code
• Use different ConfigMaps per environment
• Use subPath for specific files
• ConfigMaps update automatically (volume mounts)
• Not for sensitive data (use Secrets)