Apache Ant tagets for Composer commands.

ant-composer.xml

<?xml version="1.0" encoding="UTF-8"?>
<project name="Composer Targets" default="build">

  <property name="builddir" value="${basedir}/build"/>
  <property name="composer" value="${builddir}/composer.phar"/>

  <target name="php-check">
    <condition property="php" value="php">
      <not>
        <isset property="${php}"/>
      </not>
    </condition>
  </target>

  <target name="prepare">
    <mkdir dir="${builddir}" />
  </target>

  <target name="composer-check" depends="prepare">
    <available file="${composer}" property="composer.present"/>
  </target>

  <target name="composer-download" depends="composer-check" unless="composer.present">
    <property name="composer.noselfupdate" value="true"/>
    <get src="https://getcomposer.org/composer.phar" dest="${composer}"/>
  </target>

  <target name="composer-selfupdate" depends="php-check,composer-download" unless="composer.noselfupdate">
    <exec executable="${php}">
      <arg value="${composer}"/>
      <arg value="self-update"/>
      <arg value="--quiet"/>
    </exec>
  </target>

  <target name="composer" depends="composer-selfupdate" unless="composer.noupdate" description="Run composer update">
    <exec executable="${php}">
      <arg value="${composer}"/>
      <arg value="update"/>
    </exec>
  </target>

</project>

<exec ... failonerror="true"> may be useful to fail the entire build if Composer fails.