我没有在kubernetes上部署postgres（单节点，官方图像），并允许服务通过ClusterIP服务访问postgres。

配置相当简单 - 命名空间，部署，服务：

apiVersion: v1
kind: Namespace
metadata:

name: database

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
namespace: database
name: postgres
spec:
replicas: 1
template:

metadata:
  labels:
    app: postgres
spec:
  containers:
    - name: postgres
      image: postgres:11.1
      imagePullPolicy: "IfNotPresent"
      ports:
        - containerPort: 5432

apiVersion: v1
kind: Service
metadata:
name: pg
namespace: database
labels:

app: postgres

spec:
selector:

app: postgres

ports:

• protocol: TCP
  name: postgres
  port: 5432
  targetPort: 5432
  要测试是执行一个“/ bin / bash”进入pod并运行一个简单的psql命令来测试连接。一切都在当地很好：

kubectl --kubeconfig $k8sconf -n database exec -it $(kubectl --kubeconfig $k8sconf -n database get pods -o jsonpath='{.items[*].metadata.name}') -- psql -U admin postgresdb -c "t"
Tuples only is on.
但是一旦我尝试通过服务访问postgres，命令就会失败：

kubectl --kubeconfig $k8sconf -n database exec -it $(kubectl --kubeconfig $k8sconf -n database get pods -o jsonpath='{.items[*].metadata.name}') -- psql -h pg -U admin postgresdb -c "t"
psql: could not connect to server: Connection timed out

Is the server running on host "pg" (10.245.102.15) and accepting
TCP/IP connections on port 5432?

这是在DigitalOcean单节点集群（1.12.3）上测试的。

Postgres *在正确的端口上监听，pg_hba.conf默认情况下看起来像这样：

...
local all all trust

IPv4 local connections:

host all all 127.0.0.1/32 trust

IPv6 local connections:

host all all ::1/128 trust

Allow replication connections from localhost, by a user with the

replication privilege.

local replication all trust
host replication all 127.0.0.1/32 trust
host replication all ::1/128 trust
host all all all md5
重现看看这个要点

执行via（请使用新的群集并通读）：

export k8sconf=/path/to/your/k8s/confic/file
kubectl --kubeconfig $k8sconf apply -f https://gist.githubusercontent.com/sontags/c364751e7f0d8ba1a02a9805efc68db6/raw/01b1808348541d743d6a861402cfba224bee8971/database.yaml
kubectl --kubeconfig $k8sconf -n database exec -it $(kubectl --kubeconfig $k8sconf -n database get pods -o jsonpath='{.items[*].metadata.name}') -- /bin/bash /reproducer/runtest.sh
为什么服务不允许连接或其他测试执行？