python连接到docker外部的postgres docker实例

我可以确认docker容器正在运行：

Name                      Command                  State     Ports
-----------------------------------------------------------------------------------------------
adminer_1             entrypoint.sh docker-php-e ...   Up      0.0.0.0:8080->8080/tcp
db_1                  docker-entrypoint.sh postgres    Up      5432/tcp

我还可以通过adminer连接到db（下图）：

但我无法从docker外部连接Python：

# import the connect library from psycopg2
from psycopg2 import connect

table_name = "trips"

# declare connection instance
conn = connect(
    dbname = "postgres",
    user = "postgres",
    host = "localhost", #known ip 172.20.0.2
    password = "password"
)

# declare a cursor object from the connection
cursor = conn.cursor()

# execute an SQL statement using the psycopg2 cursor object
cursor.execute(f"SELECT * FROM {table_name};")

# enumerate() over the PostgreSQL records
for i, record in enumerate(cursor):
    print ("\n", type(record))
    print ( record )

# close the cursor object to avoid memory leaks
cursor.close()

# close the connection as well
conn.close()

出现错误：

psycopg2.OperationalError: could not connect to server: Connection refused
        Is the server running on host "localhost" (::1) and accepting
        TCP/IP connections on port 5432?
could not connect to server: Connection refused
        Is the server running on host "localhost" (fe80::1) and accepting
        TCP/IP connections on port 5432?
could not connect to server: Connection refused
        Is the server running on host "localhost" (127.0.0.1) and accepting
        TCP/IP connections on port 5432?

在中，还尝试了与postgres一起检查ip是否正在侦听：

docker inspect db_1 | grep "IPAddress"
            "SecondaryIPAddresses": null,
            "IPAddress": "",
                    "IPAddress": "172.20.0.2",

并用

172.20.0.2

替换了我python脚本中的

主机

，但我仍然无法连接。

您的docker容器“集合”仅向外部世界公开（转发）一个端口（即您的本地主机）；8080是您的管理员网站。因此，您可以访问该数据库，并且与数据库位于同一内部网络上的数据库可以找到该数据库，但是您无法访问该数据库，因为端口未公开/转发

您将希望以与web端口相同的方式转发DB端口。注意，在第一个屏幕截图中，您可以看到adminer_1正在将8080转发到外部，而db_1没有转发

如果您正在使用docker compose，则可能需要添加：

ports:
  - "5432:5432"

---

符合您的postgres容器规格。

正确！这就解决了问题，非常感谢。