Question

问题：

我的flask API无法连接到我的Postgres实例。我已验证数据库和api均能按预期工作，并且部署和服务都在kubernetes中运行。它必须是连接本身。连接是在Flask配置文件中定义的，所以也许我没有正确指定它？我无所适从。

错误

这是我在检查特定于该API的Pod日志时看到的错误，该API试图与Postgres取得联系。

sqlalchemy.exc.OperationalError: (psycopg2.OperationalError) could not connect to server: Connection timed out
       Is the server running on host "postgres" (198.105.244.228) and accepting
       TCP/IP connections on port 5432?

堆栈信息

Minikube
Kubernetes
Docker
烧瓶
Postgres
SQLAlchemy

Flask / Config.py

SQLALCHEMY_DATABASE_URI = 'postgres://postgres:postgres@postgres:5432/postgres'。这与我切换到Kubernetes之前使用Docker Compose的情况相同。

Kubernetes / postgres-cluster-ip-service.yaml

apiVersion: v1
kind: Service
metadata:
  name: postgres-cluster-ip-service
spec:
  type: ClusterIP
  selector:
    component: postgres
  ports:
    - port: 5432
      targetPort: 5432

Kubernetes / postgres-deployment.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: postres-deployment
spec:
  replicas: 1
  selector:
    matchLabels:
      component: postgres
  template:
    metadata:
      labels:
        component: postgres
    spec:
      volumes:
        - name: postgres-storage
          persistentVolumeClaim:
            claimName: database-persistent-volume-claim
      imagePullSecrets:
        - name: regcred
      containers:
        - name: postgres
          image: my/image-db
          ports:
            - containerPort: 5432
          env:
            - name: POSTGRES_PASSWORD
              value: postgres
            - name: POSTGRES_USER
              value: postgres
          volumeMounts:
            - name: postgres-storage
              mountPath: /var/lib/postgresql/data
              subPath: postgres

Kuberenetes /数据库持久卷声明

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: database-persistent-volume-claim
spec:
  # Access mode gets some instance of storage.
  # ReadWriteOncence means that it can be used by a single node.
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      # find a storage option that has at least 2 gigs of space
      storage: 2Gi

很高兴添加任何其他有帮助的文件！

Answer 1

服务的名称是主机名，因此您应该连接到import javax.swing.*; import javax.swing.table.DefaultTableModel; import java.awt.BorderLayout; import java.awt.event.*; public class AddToTable { public static void main(String[] args) { JTable jTable = new JTable(new DefaultTableModel( new Object[][] {}, new String[] {"Item", "Qty", "Price", "ID"})); JComboBox<String> jComboBox = new JComboBox<>(); jComboBox.addItem("Item1 _ 2 _ 2.5 _ 101"); jComboBox.addItem("Item2 _ 5 _ 6 _ 201"); jComboBox.addItem("Item3 _ 3 _ 1.5 _ 301"); jComboBox.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e) { Object items = jComboBox.getSelectedItem(); String name = (String) items; String[] part = name.split(" _ "); String item = (part[0]); Integer qty = Integer.valueOf((part[1])); Double price = Double.parseDouble((part[2])); Integer ids = Integer.valueOf(part[3]); DefaultTableModel df = (DefaultTableModel) jTable.getModel(); int rows = df.getRowCount(); boolean found = false; for (int i = 0; i < rows; i++) { if (ids.equals(jTable.getValueAt(i, 3))) { Integer newQty = qty + (Integer) jTable.getValueAt(i, 1); Double newPrice = price + (Double) jTable.getValueAt(i, 2); jTable.setValueAt(newQty, i, 1); jTable.setValueAt(newPrice , i, 2); found = true; break; } } if (!found) { df.addRow(new Object[]{item, qty, price, ids}); } } }); JFrame f = new JFrame(); f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); f.getContentPane().add(jComboBox, BorderLayout.NORTH); f.getContentPane().add(new JScrollPane(jTable), BorderLayout.CENTER); f.setBounds(300, 200, 400, 300); f.setVisible(true); } }（如果要部署到其他Kubernetes命名空间，请更改postgres-cluster-ip-service.default.svc.cluster.local）。您的错误消息似乎是您正在连接集群环境之外的其他名为default的系统。

Answer 2

只需为上述搜索添加到@David的正确答案中即可

SQLALCHEMY_DATABASE_URI的格式为：

schema://username:password@SERVER:PORT/databasename

我的失败原因是因为我认为我的服务器名称是我的Kubernetes postgres-deployment文件定义的Postgres。但是，我有一个单独的“服务”文件，称为postgres-cluster-ip-service。我第二次将其设置为服务器名称，连接开始工作。确保您不是将服务器直接指向服务器，而是将其前面的IP服务指向Kubernetes。

示例：

postgres://username:password@postgres-cluster-ip-service:5432/databasename

Flask Postgres连接因Kubernetes和Docker而失败

2 个答案: