Docker compose(v2)UnkownHostException

Question

docker-compose.yml更新#1

版本：“2”

服务:
Web:

-db


图像:thomptr/rest-services-ui:最新
端口:
链接:
-db:database
重新启动：始终>envtarget:dev

db:
映像:mySQL:5.7
端口:
“3307:3306”
卷:
“/home/trevor/softwaredev/mysql/dump://docker-entrypoint-initdb.d”
环境
mysql_password:legion03

application-dev.properties更新#1

spring.profiles.active=dev
server.contextPath=/restservices
server.port: 9000

spring.datasource.initialize=false
spring.datasource.platform=mysql
spring.datasource.driverClassName=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://database:3306/dev

spring.datasource.username=dbuser
spring.datasource.password=legion03;
hibernate.level.logging=debug

spring.jpa.hibernate.ddl-auto=update
spring.jpa.hibernate.naming_strategy=org.hibernate.cfg.ImprovedNamingStrategy
spring.jpa.database=mysql
spring.jpa.show-sql=true
spring.jpa.generate-ddl=true
spring.jpa.database-platform=org.hibernate.dialect.MySQLDialect

来自/dockercompose_web_1容器的日志

 2016-07-01 04:17:24.119 ERROR 1 --- [ost-startStop-1] o.a.tomcat.jdbc.pool.ConnectionPool      : Unable to create initial connections of pool.
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
Caused by: java.net.UnknownHostException: mysql: unknown error
    at java.net.Inet6AddressImpl.lookupAllHostAddr(Native Method)

更新#2 Nguyen Sy Thanh Son建议的方法是正确的。我的解决方案使用公共wait-fo-it.sh脚本。在这里查看我的解决方案：https://github.com/thomptr/dockerdemo




Answer 1

当Web容器在MySQL容器启动之前启动时，将发生此错误。

为了解决这个问题，我认为您应该在Web映像的entrypont.sh中添加一个脚本，如下所示

host="db"
password="$MYSQL_ROOT_PASSWORD" #mysql root password

until mysql -h "$host" -uroot -p$password; do
  >&2 echo "MYSQL is unavailable - sleeping"
  sleep 1
done

>&2 echo "MYSQL is up - executing command"

# start your app here

上面的脚本将等到mysql启动后再运行应用程序

# run app
COPY entrypoint.sh /
RUN chmod +x /entrypoint.sh

ENTRYPOINT ["/entrypoint.sh"]