mongo.deployment.yml

apiVersion: v1
kind: ConfigMap
metadata:
  labels:
    app: mongo-secrets-env
  name: mongo-secrets-env
data:
  MONGODB_DBNAME: codeWithDan
  MONGO_INITDB_ROOT_USERNAME: admin

---

kind: StorageClass
apiVersion: storage.k8s.io/v1
metadata:
  name: local-storage
provisioner: kubernetes.io/no-provisioner
# The reclaim policy applies to the persistent volumes not the storage class itself. 
# pvs and pvcs that are created using that storage class will inherit the reclaim policy set here.
reclaimPolicy: Retain
volumeBindingMode: WaitForFirstConsumer

---

# Note: While a local storage PV works, going with a more durable solution (NFS, cloud option, etc.) is recommended
# Adding this for demo purposes to run on Docker Desktop Kubernetes since it only supports a single Node
# https://kubernetes.io/blog/2018/04/13/local-persistent-volumes-beta/
apiVersion: v1
kind: PersistentVolume
metadata:
  name: mongo-pv
spec:
  capacity:
    storage: 1Gi
  # volumeMode block feature gate enabled by default with 1.13+
  volumeMode: Filesystem
  accessModes:
  - ReadWriteOnce
  # StorageClass has a reclaim policy default so it'll be "inherited" by the PV
  # persistentVolumeReclaimPolicy: Retain
  storageClassName: local-storage
  local:
    path: /tmp/data/db
  nodeAffinity:
    required:
      nodeSelectorTerms:
      - matchExpressions:
        - key: kubernetes.io/hostname
          operator: In
          values:
          - docker-desktop

---

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: mongo-pvc
spec:
  accessModes:
  - ReadWriteOnce
  storageClassName: local-storage
  resources:
    requests:
      storage: 1Gi

---

apiVersion: apps/v1
kind: StatefulSet
metadata:
  labels:
    app: mongo
  name: mongo
spec:
  serviceName: mongo
  replicas: 1
  selector:
    matchLabels:
      app: mongo
  template:
    metadata:
      labels:
        app: mongo
    spec:
      volumes:
      - name: mongo-volume
        persistentVolumeClaim:
          claimName: mongo-pvc
        # Example only - environment vars actually used here
      - name: secrets
        secret:
          secretName: db-passwords
      containers:
      - env:
        - name: MONGODB_DBNAME
          valueFrom:
            configMapKeyRef:
              key: MONGODB_DBNAME
              name: mongo-secrets-env
        - name: MONGO_INITDB_ROOT_USERNAME
          valueFrom:
            configMapKeyRef:
              name: mongo-secrets-env
              key: MONGO_INITDB_ROOT_USERNAME
        # Pull password from secrets
        - name: MONGO_INITDB_ROOT_PASSWORD
          valueFrom:
            secretKeyRef:
              name: db-passwords
              key: db-password
        image: mongo
        name: mongo
        ports:
        - containerPort: 27017
        resources: {}        
        volumeMounts:
        - name: mongo-volume
          mountPath: /data/db
        # Example only - environment vars actually used here
        - name: secrets
          mountPath: /etc/db-passwords
          readOnly: true