Microk8sで同一ポッド内にPostgreSQLとApache Supersetを配置する

Apache SupersetはPython製のBIツールです。Microk8sで同一ポッド内にPostgreSQLとApache Supersetを配置するには、以下の手順を実行します。

実行手順

1. local永続ボリュームで使用するディレクトリの作成
以下のコマンドでlocal永続ボリュームで使用するディレクトリを作成します。

sudo mkdir -p /var/pg-data

sudo mkdir -p /var/superset-data

cd /var/superset-data

SECRET_KEY=`echo -e "import os; print(os.urandom(24).hex())" | python3`

cat << EOF | sudo tee superset_config.py
# Superset specific config
ROW_LIMIT = 5000

BABEL_DEFAULT_LOCALE='ja'

SUPERSET_WEBSERVER_PORT = 8088

# Flask App Builder configuration
# Your App secret key
#SECRET_KEY = '\2\1thisismyscretkey\1\2\e\y\y\h'
SECRET_KEY = '#####'

# The SQLAlchemy connection string to your database backend
# This connection defines the path to the database that stores your
# superset metadata (slices, connections, tables, dashboards, ...).
# Note that the connection information to connect to the datasources
# you want to explore are managed directly in the web UI
#SQLALCHEMY_DATABASE_URI = 'sqlite:////path/to/superset.db'
SQLALCHEMY_DATABASE_URI = 'postgresql://postgres:mypostgres@127.0.0.1/superset'

# Flask-WTF flag for CSRF
WTF_CSRF_ENABLED = True
# Add endpoints that need to be exempt from CSRF protection
WTF_CSRF_EXEMPT_LIST = []
# A CSRF token that expires in 1 year
WTF_CSRF_TIME_LIMIT = 60 * 60 * 24 * 365

# Set this API key to enable Mapbox visualizations
MAPBOX_API_KEY = ''
EOF

sudo sed -i "s/#####/$SECRET_KEY/" superset_config.py

cd

2. local永続ボリュームの作成
以下のコマンドでlocal永続ボリュームを作成します。
※PostgreSQLデータ用

cat << EOF > local-pg-pv.yml
apiVersion: v1
kind: PersistentVolume
metadata:
  name: local-pg-pv
spec:
  capacity:
    storage: 5Gi
  accessModes:
  - ReadWriteOnce
  storageClassName: local-storage
  local:
    path: /var/pg-data
  nodeAffinity:
    required:
      nodeSelectorTerms:
      - matchExpressions:
        - key: kubernetes.io/hostname
          operator: In
          values:
          - `hostname`
EOF

microk8s kubectl apply -f ./local-pg-pv.yml

※superset用

cat << EOF > local-superset-pv.yml
apiVersion: v1
kind: PersistentVolume
metadata:
  name: local-superset-pv
spec:
  capacity:
    storage: 5Gi
  accessModes:
  - ReadWriteOnce
  storageClassName: local-storage
  local:
    path: /var/superset-data
  nodeAffinity:
    required:
      nodeSelectorTerms:
      - matchExpressions:
        - key: kubernetes.io/hostname
          operator: In
          values:
          - `hostname`
EOF

microk8s kubectl apply -f ./local-superset-pv.yml

3. 永続ボリューム要求の作成
以下のコマンドで永続ボリューム要求を作成します。
※PostgreSQL用

cat << EOF > local-pg-pvc.yml
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: local-pg-pvc
spec:
  accessModes:
    - ReadWriteOnce
  storageClassName: local-storage
  resources:
    requests:
      storage: 5Gi
  volumeName: local-pg-pv
EOF

microk8s kubectl apply -f ./local-pg-pvc.yml

※superset用

cat << EOF > local-superset-pvc.yml
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: local-superset-pvc
spec:
  accessModes:
    - ReadWriteOnce
  storageClassName: local-storage
  resources:
    requests:
      storage: 5Gi
  volumeName: local-superset-pv
EOF

microk8s kubectl apply -f ./local-superset-pvc.yml

4. SupersetとPostgrelSQLのDeploymentの作成
以下のコマンドでsupersetとPostgreSQLを含むポッドと作成したlocal永続ボリュームを使用するDeploymentを作成します。

cat << EOF > superset-pg-deployment.yml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: superset-pg-deployment
  labels:
    app: superset-pg
spec:
  replicas: 1
  selector:
    matchLabels:
      app: superset-pg
  strategy:
    type: Recreate
  template:
    metadata:
      labels:
        app: superset-pg
    spec:
      containers:
      - name: mypg
        image: postgres:14-alpine
        env:
        - name: POSTGRES_DB
          value: superset
        - name: POSTGRES_PASSWORD
          value: mypostgres
        ports:
        - containerPort: 5432
        volumeMounts:
        - name: pgdata
          mountPath: /var/lib/postgresql/data
      - name: superset
        image: apache/superset:latest
        command: ["/bin/sh","-c"]
        args: ["pip install psycopg2 ; superset fab create-admin --username admin --firstname Superset --lastname Admin --email admin@superset.com --password admin ; superset db upgrade ; superset load_examples ; superset init ; /usr/bin/run-server.sh"]
        env:
        - name: PYTHONPATH
          value: /opt
        ports:
        - containerPort: 8088
        volumeMounts:
        - name: superset
          mountPath: /opt
      volumes:
      - name: pgdata
        persistentVolumeClaim:
          claimName: local-pg-pvc
      - name: superset
        persistentVolumeClaim:
          claimName: local-superset-pvc
EOF

microk8s kubectl apply -f ./superset-pg-deployment.yml

5. サービスの作成
以下のコマンドでサービスを作成します。

cat << EOF > superset-service.yml
apiVersion: v1
kind: Service
metadata:
  name: superset-service
spec:
  selector:
    app: superset-pg
  type: LoadBalancer
  externalIPs:
  - xxx.xxx.xxx.xxx # 外部からアクセスできるMicrok8sをインストールしたホストのIPを設定します。
  ports:
  - name: http
    protocol: TCP
    port: 8080
    targetPort: 8088
  - name: db
    protocol: TCP
    port: 5432
    targetPort: 5432
EOF

microk8s kubectl apply -f ./superset-service.yml

ブラウザからhttp://<ホスト名:8080 にアクセスします。ユーザ名admin、パスワードadminでログインします。

〇Apache Supersetの画面