After a bit of research I was led to think that Docker containers could be a good fit for database integration testing using test containers, as this would only require a Docker container running a database image reproducing the database schema against which the tests would be executed. This instance can either be run locally on each developer’s machine or, even better, one single instance can be shared by multiple developers: an automated test can be configured to start a database instance from the same image in Docker for every test method if needed using the @Rule annotation.
While trying to install Docker for Windows 7 to play with it, I kept getting the following error which seems to be related to VirtualBox:
docker Error creating machine: Error in driver during machine creation: Unable to start the VM: VBoxManage.exe startvm default --type headless failed:
Result code: E_FAIL (0x80004005)
Component: MachineWrap
Interface: IMachine
I will share how I worked around this problem to help other people who may have run into the same problem.
To workaround the issue described in the question, I followed the steps below:
Using iso file from Ubuntu website, run an Ubuntu appliance on VMware player
$ sudo apt-get install docker.io
$ sudo groupadd docker
$ sudo usermod -aG docker $USER
so that your group membership is re-evaluated
$ docker run hello-world
In this example it's Oracle 11g:
$ docker pull wnameless/oracle-xe-11g-r2
(if you plan to connect to the Oracle database instance from testcontainers, this step is not necessary)
$ docker run -d -p 49161:1521 wnameless/oracle-xe-11g-r2
For further details/options refer to docker hub:
Using with following settings:
hostname: localhost
port: 49161
sid: xe
service name: xe
username: system
password: oracle
To connect from the host machine use the IP address of the VM instead of localhost . Run ifconfig on the guest Ubuntu VM to get the IP address
Configure where the Docker daemon listens for connections (Required only if Docker needs to be accessed remotely, i.e. not from the guest Ubuntu system), as by default Docker daemon listens on unix sockets (local connections)
Create /etc/systemd/system/docker.service.d/override.conf file with content to override default one (ExecStart=/usr/bin/dockerd -H fd://):
# /etc/systemd/system/docker.service.d/override.conf
[Service]
ExecStart=
ExecStart=/usr/bin/dockerd -H fd:// -H tcp://0.0.0.0:2376
To create this file you can run the following unix command:
printf "# /etc/systemd/system/docker.service.d/override.conf\n[Service]\nExecStart=\nExecStart=/usr/bin/dockerd -H fd:// -H tcp://0.0.0.0:2376" > /etc/systemd/system/docker.service.d/override.conf
After saving this file, reload the configuration by running:
systemctl daemon-reload
Then restart Docker by running:
systemctl restart docker.service
After restarting docker service, you can see the port number in the output of either:
systemctl status docker.service
(You should see something like: /usr/bin/dockerd -H fd:// -H tcp://0.0.0.0:2376)
Or
sudo netstat -tunlp | grep dock
(You should see something like: tcp6 0 0 :::2376 :::* LISTEN 121686/dockerd)
How do I enable the remote API for dockerd
How to detect a docker daemon port
Configure where the docker daemon listens for connections
This step is necessary only if you plan to connect remotely to the database container using testcontainers API (e.g. from a Junit test) from the OS hosting the Ubuntu VM (docker dameon is running on the ubuntu VM)
Define environment variable: DOCKER_HOST = tcp://<Ubuntu machine's IP address>:2376 . Note the hostname is the ubuntu VM's. If this environment variable is not defined, testcontainers API (OracleContainer oracleContainer = new OracleContainer("wnameless/oracle-xe-11g");) will be expecting Docker daemon to be running on localhost (See code snippet further below)
Using testcontainer API, a Junit test can start a database instance from a the Docker image on Ubuntu's VM, execute queries against it and, eventually shut it down
package com.xxx.yyy.repository;
import static org.junit.Assert.assertEquals;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.time.LocalDateTime;
import java.util.concurrent.TimeoutException;
import org.junit.ClassRule;
import org.junit.jupiter.api.AfterAll;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.TestInstance;
import org.junit.jupiter.api.TestInstance.Lifecycle;
import org.testcontainers.containers.OracleContainer;
@TestInstance(Lifecycle.PER_CLASS)
public class MyRepositoryIT {
@ClassRule
public OracleContainer oracleContainer;
@BeforeAll
public void setup() throws TimeoutException {
String dockerHost = System.getenv("DOCKER_HOST");
System.out.println("dockerHost: @" + dockerHost + "@");
System.out.println("Starting Oracle Container... (" + LocalDateTime.now() + ")");
oracleContainer = new OracleContainer("wnameless/oracle-xe-11g");
oracleContainer.start();
System.out.println("Oracle Container started. (" + LocalDateTime.now() + ")");
}
@AfterAll
public void tearDown() {
System.out.println("Stopping Oracle Container... (" + LocalDateTime.now() + ")");
oracleContainer.stop();
System.out.println("Oracle Container stopped. (" + LocalDateTime.now() + ")");
}
@Test
public void whenSelectQueryExecuted_thenResulstsReturned() throws Exception {
String jdbcUrl = oracleContainer.getJdbcUrl();
String username = oracleContainer.getUsername();
String password = oracleContainer.getPassword();
Connection conn = DriverManager.getConnection(jdbcUrl, username, password);
ResultSet resultSet = conn.createStatement().executeQuery("SELECT 1 FROM DUAL");
resultSet.next();
int result = resultSet.getInt(1);
assertEquals(1, result);
}
}
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.xxx.yyy</groupId>
<artifactId>docker-testcontainers</artifactId>
<version>0.0.1-SNAPSHOT</version>
<properties>
<java.version>1.8</java.version>
<spring.version>5.1.3.RELEASE</spring.version>
<testcontainers.version>1.10.2</testcontainers.version>
<junit-engine.version>5.3.2</junit-engine.version>
<junit-launcher.version>1.3.2</junit-launcher.version>
<maven-compiler-plugin.version>3.7.0</maven-compiler-plugin.version>
</properties>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>${maven-compiler-plugin.version}</version>
<configuration>
<source>${java.version}</source>
<target>${java.version}</target>
</configuration>
</plugin>
</plugins>
</build>
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.testcontainers</groupId>
<artifactId>testcontainers</artifactId>
<version>${testcontainers.version}</version>
</dependency>
<dependency>
<groupId>org.testcontainers</groupId>
<artifactId>oracle-xe</artifactId>
<version>${testcontainers.version}</version>
</dependency>
<dependency>
<groupId>com.oracle</groupId>
<artifactId>ojdbc6</artifactId>
<version>12.1.0.2</version>
</dependency>
<dependency>
<groupId>org.junit.jupiter</groupId>
<artifactId>junit-jupiter-engine</artifactId>
<version>${junit-engine.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.junit.platform</groupId>
<artifactId>junit-platform-launcher</artifactId>
<version>${junit-launcher.version}</version>
<scope>test</scope>
</dependency>
</dependencies>
docker imagesdocker ps -adocker start [container id]docker psdocker logs [container id]Further details about Post-install steps
Using an Oracle image within Docker
Database Testing With TestContainers
I've tried an Oracle 12c image (sath89/oracle-12c from: https://hub.docker.com/r/sath89/oracle-12c)
$ docker run -d -p 8080:8080 -p 1521:1521 --name oracle-db-12c sath89/oracle-12c
but it seems to be so slow starting up from testcontainers that the following exception is eventually (after approximately 4 minutes) thrown:
java.sql.SQLRecoverableException: ORA-01033: ORACLE initialization or shutdown in progress.
If the 12c image is started from docker host itself (i.e. Ubuntu), it does start successfully.