Can't access mysql container by hostname from a spring boot container within the same network - mysql

Question

I'm trying to access my MySQL container from another Spring Boot application container, which are both in the same network.
I've created a network and linked both containers to it :
docker network create --driver bridge dmw_network
Details of my network :
[
{
"Name": "dmw_network",
"Id": "2e204b7b48efafc5db0daccb801a3e38a0f1b99a6a745dd9b58a74172e966da3",
"Created": "2018-09-25T17:28:35.530261782+02:00",
"Scope": "local",
"Driver": "bridge",
"EnableIPv6": false,
"IPAM": {
"Driver": "default",
"Options": {},
"Config": [
{
"Subnet": "172.19.0.0/16",
"Gateway": "172.19.0.1"
}
]
},
"Internal": false,
"Attachable": false,
"Ingress": false,
"ConfigFrom": {
"Network": ""
},
"ConfigOnly": false,
"Containers": {
"28b1368d9256f0b323b528507ea9133ba410c691fbd01029ee3913eacfa94660": {
"Name": "dmwapp",
"EndpointID": "f59f82bf0e62fb97fa7b1b4e0c3750adffaf570a93de633938de32a199ba03ab",
"MacAddress": "02:42:ac:13:00:03",
"IPv4Address": "172.19.0.3/16",
"IPv6Address": ""
},
"c6ed1cbdd376714c90c5e67024cc576030b030e29a9a8d766bb4bb637025dd08": {
"Name": "mysql5",
"EndpointID": "0ea9594ebb4251d5f13c05f407e660c2ed1b5e4ccaed2d71cedc610984b9b076",
"MacAddress": "02:42:ac:13:00:02",
"IPv4Address": "172.19.0.2/16",
"IPv6Address": ""
}
},
"Options": {},
"Labels": {}
}
]
Here is my application.yml file :
spring:
application:
name : ${appName:tasky}
datasource:
url: jdbc:mysql://mysql5:3406/dmw_db?autoReconnect=true&useSSL=false
username: user
password: pass
driver-class-name: com.mysql.jdbc.Driver
tomcat:
max-active: 50
max-idle: 50
And this is how I run both my containers :
docker run --name=mysql5 --network=dmw_network -p 3406:3306 -v $(pwd)/mysql:/var/lib/mysql -e MYSQL_ROOT_PASSWORD=pass -d dmw_mysql5
docker run --name dmwapp --network=dmw_network -d -p 8888:8888 -p 9999:9999 -v $(pwd)/conf:/home/conf/config/prod dmwimg
Yet I'm still unable to access my database by hostname from my other spring boot container in the same network.
Here is the error :
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 3 times. Giving up.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
at com.mysql.jdbc.Util.getInstance(Util.java:408)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:919)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:898)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:887)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:861)
at com.mysql.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:2096)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2021)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:776)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:386)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:330)
at org.apache.tomcat.jdbc.pool.PooledConnection.connectUsingDriver(PooledConnection.java:319)
at org.apache.tomcat.jdbc.pool.PooledConnection.connect(PooledConnection.java:212)
at org.apache.tomcat.jdbc.pool.ConnectionPool.createConnection(ConnectionPool.java:736)
at org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:668)
at org.apache.tomcat.jdbc.pool.ConnectionPool.init(ConnectionPool.java:483)
at org.apache.tomcat.jdbc.pool.ConnectionPool.<init>(ConnectionPool.java:154)
at org.apache.tomcat.jdbc.pool.DataSourceProxy.pCreatePool(DataSourceProxy.java:118)
at org.apache.tomcat.jdbc.pool.DataSourceProxy.createPool(DataSourceProxy.java:107)
at org.apache.tomcat.jdbc.pool.DataSourceProxy.getConnection(DataSourceProxy.java:131)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at net.bull.javamelody.JdbcWrapper$3.invoke(JdbcWrapper.java:781)
at net.bull.javamelody.JdbcWrapper$DelegatingInvocationHandler.invoke(JdbcWrapper.java:294)
at com.sun.proxy.$Proxy139.getConnection(Unknown Source)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:216)
... 117 more
Caused by: 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.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:990)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:342)
at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2188)
at com.mysql.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:2037)
... 148 more
Caused by: java.net.ConnectException: Connection refused (Connection refused)
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.net.Socket.connect(Socket.java:589)
at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:211)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:301)
... 150 more
When I'm switching to the IP address of the server hosting the docker containers then it works. For example :
url: jdbc:mysql://184.4.x.x:3406/dmw_db?autoReconnect=true&useSSL=false
What am I doing wrong ?

Answer 1

Change port form 3406 to proper one.
url: jdbc:mysql://mysql5:3306/dmw_db?autoReconnect=true&useSSL=false
If you are connecting using docker name you should use internal port not exposed one.

Answer 2

dmwapp doesn't know anything about an alias mysql5. You may link them during running:
docker run --name dmwapp --network=dmw_network -d -p 8888:8888 -p 9999:9999 -v $(pwd)/conf:/home/conf/config/prod --link mysql5:mysql5 dmwimg