0

I have a dropwizard application and a docker container running my mysql database. I want to create a docker container with my dropwizard project and migrate the db using the config.yml file.

I created my own network - mynet.

First, I run the mysql container using this command:

docker run --name mysql -e MYSQL_ROOT_PASSWORD=root -e MYSQL_DATABASE=wrapper --network mynet mysql:latest

Then, on the host I run mvn clean install to create the .jar and I start a container with the jar file and the config.yml files copied.

I start the dropwizard container:

docker run -it --network mynet -v $(pwd)/config.yml:/ideaDB/config.yml -p 9004:9004 -p 9005:9005 dropwizard-ideadb sh and run:

java -jar ideadb-SNAPSHOT.jar db migrate config.yml

but I get the following error:

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:400)
    at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1038)
    at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:339)
    at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2247)
    at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2280)
    at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2079)
    at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:794)
    at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:44)
    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:400)
    at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:399)
    at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:325)
    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:739)
    at org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:671)
    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 io.dropwizard.migrations.AbstractLiquibaseCommand.createDatabase(AbstractLiquibaseCommand.java:94)
    at io.dropwizard.migrations.AbstractLiquibaseCommand.openLiquibase(AbstractLiquibaseCommand.java:79)
    at io.dropwizard.migrations.AbstractLiquibaseCommand.run(AbstractLiquibaseCommand.java:67)
    at io.dropwizard.cli.ConfiguredCommand.run(ConfiguredCommand.java:87)
    at io.dropwizard.cli.Cli.run(Cli.java:78)
    at io.dropwizard.Application.run(Application.java:93)
    at org.tmms.ideadb.IdeadbserviceApplication.main(IdeadbserviceApplication.java:80)
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:214)
    at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:298)
    ... 28 more
ERROR [2019-03-26 10:57:50,654] org.apache.tomcat.jdbc.pool.ConnectionPool: Unable to create initial connections of pool.
! 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:214)
! at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:298)
! ... 28 common frames omitted
! Causing: 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:400)
! at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1038)
! at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:339)
! at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2247)
! at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2280)
! at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2079)
! at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:794)
! at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:44)
! 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:400)
! at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:399)
! at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:325)
! 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:739)
! at org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:671)
! 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 io.dropwizard.migrations.AbstractLiquibaseCommand.createDatabase(AbstractLiquibaseCommand.java:94)
! at io.dropwizard.migrations.AbstractLiquibaseCommand.openLiquibase(AbstractLiquibaseCommand.java:79)
! at io.dropwizard.migrations.AbstractLiquibaseCommand.run(AbstractLiquibaseCommand.java:67)
! at io.dropwizard.cli.ConfiguredCommand.run(ConfiguredCommand.java:87)
! at io.dropwizard.cli.Cli.run(Cli.java:78)
! at io.dropwizard.Application.run(Application.java:93)
! at org.tmms.ideadb.IdeadbserviceApplication.main(IdeadbserviceApplication.java:80)

This is my config.yml file:

defaultName: Stranger
defaultEmptyResponse: No Data Received
server:
  applicationConnectors:
  - type: http 
    port: 9004
  adminConnectors:
  - type: http
    port: 9005    

# Database settings.
database:
    # the name of the JDBC driver
    driverClass: com.mysql.jdbc.Driver
    # the username
    user: root
    # the password
    password: root
    # the JDBC URL; the database is called tmms
    url: jdbc:mysql://mysql:3306/wrapper

swagger:
  resourcePackage: ideadb

In the url, mysql is the name of my running mysql container.

What should be the correct url in the config.yml file to connect to mysql?

bunjee
  • 11
  • 1
  • 5
  • IMO your configuration is OK. I've checked the `docker` documentation: you are using [`user-defined bridge network`](https://docs.docker.com/network/network-tutorial-standalone/#use-user-defined-bridge-networks). There the hostname resolution should work fine for the named containers. I think your problem is something about the MySQL server network configuration. You are getting `connection refused`. If the `mysql` is not resolvable to an IP address, the message should be other. – zloster Mar 31 '19 at 12:41
  • Check here the posible reasons for `Connection refused`: https://stackoverflow.com/questions/6876266/java-net-connectexception-connection-refused#6876306 – zloster Mar 31 '19 at 12:41
  • Having the knowledge above you need to verify the following things: 1) Is `mysql` daemon in the mysql docker containter configured to listen for connections on the network interfaces? 2) Is there firewall or something similar that prevents the connection to the `mysql` daemon process over the network (connection to the default 3306 port)? 3) Is the username I'm using to connect to the DB is authorised to connect over the network? Some details here: https://bgasparotto.com/enable-mysql-remote-access – zloster Mar 31 '19 at 12:41

0 Answers0