无法将app engine连接到mysql实例的云sql

Question

sqlalchemy.exc.操作错误：（pymysql.err.操作错误）（2003，"无法连接到MySQL服务器上的'localhost'（[错误2]没有这样的文件或目录）"）（此错误的背景：http://sqlalche.me/e/e3q8）

它已经很长时间我被困在这个错误，我试图将我的应用程序引擎python代码连接到mysql实例的云sql。这是我第一次使用谷歌cloud.below是我写的代码1。在app.yaml

runtime:
    python37
vpc_access_connector:
    name: "projects/projectnameandcode/locations/location name/connectors/connector name"

2.要求。txt文件

sqlalchemy
pymysql

总的来说。py公司

导入pymysql

db=sqlalchemy。创建\u引擎(

sqlalchemy.engine.url.URL(
    drivername="mysql+pymysql",
    username="username",
    password=password,
    database="databasename",
    query={"unix_socket": "/cloudsql/{}".format("instance name")},
),

)a=分贝。connect（）

为什么我要面对这个问题？我的Iam角色是所有者或管理员。

Answer 1

快速查看从App Engine连接到云SQL留档，并确保您正确执行了所有步骤。具体来说，请确保以下内容：

1. 实例具有公共IP
2. 已启用云SQL管理API
3. 服务帐户具有云SQL IAM权限

Answer 2

应用引擎标准环境不支持使用TCP连接到云SQL实例。除非配置了无服务器VPC访问，否则代码不应尝试使用IP地址（例如127.0.0.1或172.17.0.1）访问实例。

从您的问题中，我了解到您正在使用vpc_access_connector。因此，我假设您配置了无服务器VPC访问。

main.py中使用的代码用于使用unix域套接字而不是TCP连接到云SQL实例。

1.创建一个新项目

gcloud projects create con-ae-to-sql
gcloud config set project con-ae-to-sql
gcloud projects describe con-ae-to-sql

2、对您的项目启用计费：https://cloud.google.com/billing/docs/how-to/modify-project

3.运行以下gcloud命令启用App Engine并创建关联的应用程序资源

gcloud app create -region europe-west2
gcloud app describe
#Remember the location of you App Engine aplication, because we will create all our resources on the same region

4、设置计算项目信息元数据：

 gcloud compute project-info describe --project con-ae-to-sql
 #Enable the Api, and you can check that default-region,google-compute-default-zone are not set. Set the metadata.
 gcloud compute project-info add-metadata --metadata google-compute-default-region=europe-west2,google-compute-default-zone=europe-west2-b

5、启用服务网络Api：

gcloud services list --available
gcloud services enable servicenetworking.googleapis.com

6.创建2个云sql实例，（一个带有内部ip，一个带有公共ip）-https://cloud.google.com/sql/docs/mysql/create-instance：

6、具有外部ip的云Sql实例：

#Create the sql instance in the same region as App Engine Application
gcloud --project=con-ae-to-sql beta sql instances create database-external --region=europe-west2
#Set the password for the "root@%" MySQL user:
gcloud sql users set-password root --host=% --instance database-external --password root 
#Create a user
gcloud sql users create user_name --host=% --instance=database-external  --password=user_password
#Create a database
gcloud sql databases create user_database --instance=database-external
gcloud sql databases list --instance=database-external

6、内部ip的b云Sql实例：

i.#Create a private connection to Google so that the VM instances in the default VPC network can use private services access to reach Google services that support it.

gcloud compute addresses create google-managed-services-my-network     --global  --purpose=VPC_PEERING --prefix-length=16  --description="peering range for Google"  --network=default --project=con-ae-to-sql
gcloud services vpc-peerings connect --service=servicenetworking.googleapis.com --ranges=google-managed-services-my-network  --network=default  --project=con-ae-to-sql
#Check whether the operation was successful.
gcloud services vpc-peerings operations describe     --name=operations/pssn.dacc3510-ebc6-40bd-a07b-8c79c1f4fa9a
#Listing private connections
gcloud services vpc-peerings list --network=default --project=con-ae-to-sql
 
ii.Create the instance:

gcloud --project=con-ae-to-sql beta sql instances create database-ipinternal --network=default --no-assign-ip  --region=europe-west2
#Set the password for the "root@%" MySQL user:
gcloud sql users set-password root --host=% --instance database-ipinternal --password root
#Create a user
gcloud sql users create user_name --host=% --instance=database-ipinternal  --password=user_password
#Create a database
gcloud sql databases create user_database --instance=database-ipinternal
gcloud sql databases list --instance=database-ipinternal 


gcloud sql instances list
gcloud sql instances describe database-external
gcloud sql instances describe database-ipinternal
#Remember the instances connectionName

好的，我们有两个mysql实例，我们将使用无服务器访问和TCP从App Engine Standard连接到数据库ipinternal，使用unix域套接字从App Engine Standard连接到数据库外部，使用TCP从App Engine Flex连接到数据库ipinternal，使用unix域套接字从App Engine Flex连接到数据库外部。

7.启用云SQL管理API

gcloud services list --available
gcloud services enable sqladmin.googleapis.com

8、目前App Engine标准环境不支持使用TCP连接到云SQL实例。除非配置了无服务器VPC访问，否则代码不应尝试使用IP地址（如127.0.0.1或172.17.0.1）访问实例。因此，让我们配置无服务器VPC访问。

8. a确保为您的项目启用无服务器VPC访问API：

gcloud services enable vpcaccess.googleapis.com

8.b创建连接器：

gcloud compute networks vpc-access connectors create serverless-connector --network default --region europe-west2 --range 10.10.0.0/28
#Verify that your connector is in the READY state before using it
gcloud compute networks vpc-access connectors describe serverless-connector --region europe-west2

9. App Engine使用服务号来授权您与CloudSQL的连接。此服务号必须具有正确的IAM权限才能成功连接。除非另有配置，否则默认服务号采用[e-mail]格式。确保服务的服务号具有以下IAM角色：CloudSQLClient，要在内部ip上从App Engine Standard连接到Cloud Sql，我们还需要角色Compute Network User。

gcloud iam service-accounts list
gcloud projects add-iam-policy-binding con-ae-to-sql --member serviceAccount:[e-mail] --role roles/cloudsql.client
gcloud projects add-iam-policy-binding con-ae-to-sql --member serviceAccount:[e-mail] --role roles/compute.networkUser

现在我配置了设置

1、使用Tcp和unix domanin socket从App Engine Standard连接到云Sql

cd app-engine-standard/
ls
#app.yaml  main.py requirements.txt

cat requirements.txt
Flask==1.1.1
sqlalchemy
pymysql
uwsgi==2.0.18

cat app.yaml
runtime: python37
entrypoint: uwsgi --http-socket :8080 --wsgi-file main.py --callable app --master --processes 1 --threads 2
vpc_access_connector:
    name: "projects/con-ae-to-sql/locations/europe-west2/connectors/serverless-connector" 



cat main.py

from flask import Flask
import pymysql
from sqlalchemy import create_engine

# If `entrypoint` is not defined in app.yaml, App Engine will look for an app
# called `app` in `main.py`.
app = Flask(__name__)

@app.route('/')
def hello():
    engine_tcp = create_engine('mysql+pymysql://user_name:user_password@internal-ip-of-database-ipinternal:3306')
    existing_databases_tcp = engine_tcp.execute("SHOW DATABASES;")
    con_tcp = "Connecting from APP Engine Standard to Cloud SQL using TCP: databases => " + str([d[0] for d in existing_databases_tcp]).strip('[]') + "\n"
    engine_unix_socket = create_engine('mysql+pymysql://user_name:user_password@/user_database?unix_socket=/cloudsql/con-ae-to-sql:europe-west2:database-external')
    existing_databases_unix_socket = engine_unix_socket.execute("SHOW DATABASES;")
    con_unix_socket = "Connecting from APP Engine Standard to Cloud SQL using Unix Sockets: tables in sys database:  => " + str([d[0] for d in existing_databases_unix_socket]).strip('[]') + "\n"
    return con_tcp + con_unix_socket



gcloud app deploy -q
gcloud app browse
#Go to https://con-ae-to-sql.appspot.com
#Connecting from APP Engine Standard to Cloud SQL using TCP: databases => 'information_schema', 'user_database', 'mysql', 'performance_schema', 'sys' Connecting from APP Engine Standard to Cloud SQL using Unix Sockets: tables in sys database: => 'information_schema', 'user_database', 'mysql', 'performance_schema', 'sys'

成功！

2.使用Tcp和unix domanin套接字从App Engine Flex连接到Cloud Sql

cd app-engine-flex/
ls
#app.yaml  main.py requirements.txt

cat requirements.txt
Flask==1.1.1
gunicorn==19.9.0
sqlalchemy
pymysql

cat app.yaml
runtime: python
env: flex
entrypoint: gunicorn -b :$PORT main:app
runtime_config:
  python_version: 3
#Using TCP and unix sockets domain
beta_settings:
 cloud_sql_instances: con-ae-to-sql:europe-west2:database-ipinternal=tcp:3306,con-ae-to-sql:europe-west2:database-external
manual_scaling:
  instances: 1
resources:
  cpu: 1
  memory_gb: 0.5
  disk_size_gb: 10


cat main.py

from flask import Flask
import pymysql
from sqlalchemy import create_engine

app = Flask(__name__)

@app.route('/')
def hello():
    engine_tcp = create_engine('mysql+pymysql://user_name:user_password@internal-ip-of-database-ipinternal:3306')
    existing_databases_tcp = engine_tcp.execute("SHOW DATABASES;")
    con_tcp = "Connecting from APP Engine Flex to Cloud SQL using TCP: databases => " + str([d[0] for d in existing_databases_tcp]).strip('[]') + "\n"

    engine_unix_socket = create_engine('mysql+pymysql://user_name:user_password@/user_database?unix_socket=/cloudsql/con-ae-to-sql:europe-west2:database-external')
    existing_databases_unix_socket = engine_unix_socket.execute("SHOW DATABASES;")
    con_unix_socket = "Connecting from APP Engine Flex to Cloud SQL using Unix Sockets: tables in sys database:  => " + str([d[0] for d in existing_databases_unix_socket]).strip('[]') + "\n"
    return con_tcp + con_unix_socket


gcloud app deploy -q
gcloud app browse
#Go to https://con-ae-to-sql.appspot.com
#Connecting from APP Engine Flex to Cloud SQL using TCP: databases => 'information_schema', 'marian', 'mysql', 'performance_schema', 'sys' Connecting from APP Engine Flex to Cloud SQL using Unix Sockets: tables in sys database: => 'information_schema', 'marian', 'mysql', 'performance_schema', 'sys'

成功！