Docker&x2B;Mysql ConnectionError:未知的Mysql服务器主机';db';
我在Rails+MySQL Docker设置中遇到了以下错误:Docker&x2B;Mysql ConnectionError:未知的Mysql服务器主机';db';,mysql,ruby-on-rails,docker,Mysql,Ruby On Rails,Docker,我在Rails+MySQL Docker设置中遇到了以下错误: Mysql2::Error::ConnectionError: Unknown MySQL server host 'db' (-2) /usr/local/bundle/gems/mysql2-0.5.2/lib/mysql2/client.rb:90:in `connect' /usr/local/bundle/gems/mysql2-0.5.2/lib/mysql2/client.rb:90:in `initialize'
Mysql2::Error::ConnectionError: Unknown MySQL server host 'db' (-2)
/usr/local/bundle/gems/mysql2-0.5.2/lib/mysql2/client.rb:90:in `connect'
/usr/local/bundle/gems/mysql2-0.5.2/lib/mysql2/client.rb:90:in `initialize'
我的docker compose.yml
:
version: '3.7'
services:
db:
# https://github.com/passbolt/passbolt_docker/issues/103
image: mysql:5.7
restart: always
healthcheck:
test: ["CMD-SHELL", 'mysql --database=$$MYSQL_DATABASE --password=$$MYSQL_ROOT_PASSWORD --execute="SELECT count(table_name) > 0 FROM information_schema.tables;" --skip-column-names -B']
interval: 30s
timeout: 10s
retries: 4
environment:
MYSQL_DATABASE: 'db'
MYSQL_USER: 'user'
MYSQL_PASSWORD: 'password'
MYSQL_ROOT_PASSWORD: 'password'
ports:
- "3305:3306"
expose:
- '3305'
volumes:
- my-db:/var/lib/mysql
web:
build: .
command: bash -c "rm -f tmp/pids/server.pid && bundle exec rails s -p 3000 -b '0.0.0.0'"
volumes:
- '.:/app'
ports:
- '3000:3000'
environment:
DB_PORT: 3306
DB_HOST: db
DATABASE_URL: mysql2://user:password@db:3306
depends_on:
- db
volumes:
my-db:
default: &default
adapter: mysql2
encoding: utf8mb4
pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
username: user
password: password
host: localhost
url: <%= ENV['DATABASE_URL'] %>
port: 3305
和我的数据库.yml
:
version: '3.7'
services:
db:
# https://github.com/passbolt/passbolt_docker/issues/103
image: mysql:5.7
restart: always
healthcheck:
test: ["CMD-SHELL", 'mysql --database=$$MYSQL_DATABASE --password=$$MYSQL_ROOT_PASSWORD --execute="SELECT count(table_name) > 0 FROM information_schema.tables;" --skip-column-names -B']
interval: 30s
timeout: 10s
retries: 4
environment:
MYSQL_DATABASE: 'db'
MYSQL_USER: 'user'
MYSQL_PASSWORD: 'password'
MYSQL_ROOT_PASSWORD: 'password'
ports:
- "3305:3306"
expose:
- '3305'
volumes:
- my-db:/var/lib/mysql
web:
build: .
command: bash -c "rm -f tmp/pids/server.pid && bundle exec rails s -p 3000 -b '0.0.0.0'"
volumes:
- '.:/app'
ports:
- '3000:3000'
environment:
DB_PORT: 3306
DB_HOST: db
DATABASE_URL: mysql2://user:password@db:3306
depends_on:
- db
volumes:
my-db:
default: &default
adapter: mysql2
encoding: utf8mb4
pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
username: user
password: password
host: localhost
url: <%= ENV['DATABASE_URL'] %>
port: 3305
default:&default
适配器:mysql2
编码:utf8mb4
游泳池:
用户名:user
密码:密码
主机:本地主机
网址:
港口:3305
根据,我应该等MySQL启动吗?然而,我在docker compose文件的healthcheck
部分添加了一个运行状况检查,但它不起作用
我还尝试使用netcat检查端口,但它也不起作用。为什么我不能从Docker
web
容器连接到主机db
?我做错了什么?此消息抱怨缺少名为“db”的“MYSQL主机”
Mysql2::Error::ConnectionError: Unknown MySQL server host 'db' (-2)
根据您的docker编写文件
environment:
MYSQL_DATABASE: 'db'
MYSQL_USER: 'user'
MYSQL_PASSWORD: 'password'
MYSQL_ROOT_PASSWORD: 'password'
您应该在这里选择一个有效的参数(最好使用ENV变量)。
还要确保
事实证明,对于我的问题,我需要清除docker卷并重新创建所有内容 基本上是这样的:
docker-compose down
docker system prune --force --volumes
然后重新启动所有操作,确保MySQL(“db
”)在尝试连接到db
之前已成功运行。执行url:
是毫无意义的。Rails将ENV['DATABASE\u URL']
与配置合并。