docker-maven-plugin and ECR

pom.xml

<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.example</groupId>
    <artifactId>build</artifactId>
    <packaging>pom</packaging>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-antrun-plugin</artifactId>
                <executions>
                    <execution>
                        <id>ecr-login</id>
                        <phase>validate</phase>
                        <goals>
                            <goal>run</goal>
                        </goals>
                        <configuration>
                            <target>
                                <macrodef name="ecr-login" xmlns:if="ant:if" xmlns:unless="ant:unless">
                                    <attribute name="registryid" default="NOT SET"/>
                                    <attribute name="region" default="NOT SET"/>

                                    <sequential>
                                        <echo>Logging into ECR registry @{registryid} in region @{region}</echo>

                                        <local name="ecr.out"/>
                                        <local name="ecr.err"/>
                                        <exec outputproperty="ecr.out" errorproperty="ecr.err" executable="aws">
                                            <arg value="--region"/>
                                            <arg value="@{region}"/>
                                            <arg value="ecr"/>
                                            <arg value="get-login"/>
                                            <arg value="--registry-ids"/>
                                            <arg value="@{registryid}"/>
                                        </exec>

                                        <fail message="${ecr.err}">
                                            <condition>
                                                <matches string="${ecr.err}" pattern=".+"/>
                                            </condition>
                                        </fail>

                                        <exec failonerror="true" command="${ecr.out}"/>
                                    </sequential>
                                </macrodef>

                                <!-- For our own stuff -->                              
                                <ecr-login registryid="238947823742" region="eu-west-1" unless:true="${skipDocker}"/>
                                <!-- For amazonlinux -->
                                <ecr-login registryid="137112412989" region="eu-west-1" unless:true="${skipDocker}"/>
                                <echo if:true="${skipDocker}">Skipping ECR login</echo>
                            </target>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
      </plugins>
  </build>
</project>