settings.xml

<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0
                          https://maven.apache.org/xsd/settings-1.0.0.xsd">
  <servers>
    <server>
    <!--
      Note how the id element in the server element in settings.xml is identical to the
      id elements in the snapshotRepository and repository element as well as the serverId
        configuration of the Nexus Staging Maven plugin
    -->
      <id>maven</id>
      <username>${env.MAVEN_USER}</username>
      <password>${env.MAVEN_PASSWORD}</password>
    </server>
    <server>
      <id>gpg.passphrase</id>
      <passphrase>${env.GPG_PASSPHRASE}</passphrase>
    </server>
  </servers>
</settings>