错误 2002 (HY000)： 无法连接到"db"上的 MySQL 服务器 (115)

Question

我正在尝试将现有项目转移到Docker。我在M.Academy学习了本教程，并遵循了Docker关于现有项目的设置说明

在执行尝试连接MySQL时，我收到了此错误错误2002(HY000(：无法连接到"db"(115(上的MySQL服务器

我还尝试执行：telnet db 3306

回复：正在尝试172.17.0.1。。。telnet:无法连接到远程主机：连接超时

我什么都试过了，但没能解决问题。我是Docker的新手。我使用的是Ubuntu 18.04 LTE。在导入数据库之前，没有更改db.env，在任何其他步骤中都没有错误。

我进一步检查发现，容器无法与MySQL建立连接。

附言：我可以使用(外部MySQL端口(mysql -h 127.0.01 -u root -p -P 3306成功连接Docker容器外的同一MySQL服务

复制步骤

1. 安装Docker&Docker Compose on Ubuntu 18.04
2. 下载Docker Compose模板：curl -s https://raw.githubusercontent.com/markshust/docker-magento/master/lib/template | bash
3. 替换为现有Magento实例的现有源代码：cp -R ~/Sites/existing src
4. 执行：docker-compose -f docker-compose.yml up -d
5. 将文件复制到容器：bin/copytocontainer --all
6. 导入现有数据库：bin/mysql < /var/www/magento243.sql

预期结果数据库应已成功导入

实际结果错误2002(HY000(：无法连接到"db"(115(上的MySQL服务器

p.S.问题已经在这里提出：https://github.com/markshust/docker-magento/issues/589

docker compose.yml

version: "3"
services:
app:
image: markoshust/magento-nginx:1.18-5
ports:
- "80:8000"
- "443:8443"
depends_on:
- "db"
volumes: &appvolumes
- ~/.composer:/var/www/.composer:cached
- ~/.ssh/id_rsa:/var/www/.ssh/id_rsa:cached
- ~/.ssh/known_hosts:/var/www/.ssh/known_hosts:cached
- appdata:/var/www/html
- sockdata:/sock
- ssldata:/etc/nginx/certs
extra_hosts: &appextrahosts
## M1 Mac support to fix Docker delay, see #566
- "app:172.17.0.1"
- "phpfpm:172.17.0.1"
- "db:172.17.0.1"
- "redis:172.17.0.1"
- "elasticsearch:172.17.0.1"
- "rabbitmq:172.17.0.1"
## Selenium support, replace "magento.test" with URL of your site
- "magento.test:172.17.0.1"
phpfpm:
image: markoshust/magento-php:7.4-fpm-11
volumes: *appvolumes
extra_hosts: *appextrahosts
env_file: env/phpfpm.env
db:
image: mariadb:10.4
command: --max_allowed_packet=256M
ports:
- "3306:3306"
env_file: env/db.env
volumes:
- dbdata:/var/lib/mysql
extra_hosts: *appextrahosts
redis:
image: redis:5.0-alpine
ports:
- "6379:6379"
extra_hosts: *appextrahosts
elasticsearch:
image: markoshust/magento-elasticsearch:7.9.3-1
ports:
- "9200:9200"
- "9300:9300"
environment:
- "discovery.type=single-node"
## Set custom heap size to avoid memory errors
- "ES_JAVA_OPTS=-Xms1g -Xmx1g"
## Avoid test failures due to small disks
## More info at https://github.com/markshust/docker-magento/issues/488
- "cluster.routing.allocation.disk.threshold_enabled=false"
- "index.blocks.read_only_allow_delete"
extra_hosts: *appextrahosts
rabbitmq:
image: rabbitmq:3.8.22-management-alpine
ports:
- "15672:15672"
- "5672:5672"
volumes:
- rabbitmqdata:/var/lib/rabbitmq
environment:
- RABBITMQ_VM_MEMORY_HIGH_WATERMARK=1GB
extra_hosts: *appextrahosts
mailcatcher:
image: sj26/mailcatcher
ports:
- "1080:1080"
extra_hosts: *appextrahosts
## Selenium support, uncomment to enable
#selenium:
#  image: selenium/standalone-chrome-debug:3.8.1
#  ports:
#    - "5900:5900"
#  extra_hosts: *appextrahosts
volumes:
appdata:
dbdata:
rabbitmqdata:
sockdata:
ssldata:

Answer 1

最终解决了此问题

1. 从YML文件中删除extra_hosts条目
2. 在YML中添加网络

最终docker compose.yml

version: "3"
services:
app:
image: markoshust/magento-nginx:1.18-5
ports:
- "81:8000"
- "444:8443"
depends_on:
- "db"
volumes: &appvolumes
- ~/.composer:/var/www/.composer:cached
- ~/.ssh/id_rsa:/var/www/.ssh/id_rsa:cached
- ~/.ssh/known_hosts:/var/www/.ssh/known_hosts:cached
- appdata:/var/www/html
- sockdata:/sock
- ssldata:/etc/nginx/certs
networks:
- customNetwork
phpfpm:
image: markoshust/magento-php:7.4-fpm-11
volumes: *appvolumes
env_file: env/phpfpm.env
networks:
- customNetwork
db:
image: mariadb:10.4
command: --max_allowed_packet=256M
ports:
- "3307:3306"
env_file: env/db.env
volumes:
- dbdata:/var/lib/mysql
networks:
- customNetwork
redis:
image: redis:5.0-alpine
ports:
- "6379:6379"
networks:
- customNetwork
elasticsearch:
image: markoshust/magento-elasticsearch:7.9.3-1
ports:
- "9201:9200"
- "9301:9300"
environment:
- "discovery.type=single-node"
## Set custom heap size to avoid memory errors
- "ES_JAVA_OPTS=-Xms1g -Xmx1g"
## Avoid test failures due to small disks
## More info at https://github.com/markshust/docker-magento/issues/488
- "cluster.routing.allocation.disk.threshold_enabled=false"
- "index.blocks.read_only_allow_delete"
networks:
- customNetwork
rabbitmq:
image: rabbitmq:3.8.22-management-alpine
ports:
- "15672:15672"
- "5672:5672"
volumes:
- rabbitmqdata:/var/lib/rabbitmq
environment:
- RABBITMQ_VM_MEMORY_HIGH_WATERMARK=1GB
networks:
- customNetwork
mailcatcher:
image: sj26/mailcatcher
ports:
- "1080:1080"
networks:
- customNetwork
volumes:
appdata:
dbdata:
rabbitmqdata:
sockdata:
ssldata:
networks:
customNetwork: