Jenkins Maven job doesn't use localRepository from settings.xml - maven

Question

I have three Jenkins Maven jobs: one that builds and installs dependencies (JARs) and two that use those dependencies to bundle deployable WAR files.
I have configured all the three jobs to use a specific settings.xml file and, while not fully understanding the difference between the Settings file and Global Settings file (even after reading the ?, it's not clear), under Build I set both fields to the file path I wish to use, just in case:
/opt/maven/conf/settings.xml specifies:
<localRepository>/var/lib/maven/repo</localRepository>
however, the dependencies get downloaded in a different location: /var/lib/jenkins/maven-repositories/1 as /var/lib/jenkins is JENKINS_HOME.
The console output logs the following:
Executing Maven: -B -f /var/lib/code/src/pom.xml -Dmaven.repo.local=/var/lib/jenkins/maven-repositories/2 -s /opt/maven/conf/settings.xml -gs /opt/maven/conf/settings.xml clean install -P depBuild
which is confusing because maven.repo.local is different that what the file listed under -s and -gs says it should be.
Why does it not download and install dependencies in the local repo I specify in the settings.xml I tell it to use?
Here is the whole 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 http://maven.apache.org/xsd/settings-1.0.0.xsd">
<localRepository>/var/lib/maven/repo</localRepository>
<servers>
<server>
<id>build.tomcat.all</id>
<username>buildman</username>
<password>mypass</password>
</server>
</servers>
<pluginGroups></pluginGroups>
<proxies></proxies>
<mirrors></mirrors>
<profiles></profiles>
</settings>

Answer 1

Try configuring it using the Config File Provider Plugin. After installing this plugin, you can create a config file in Manage Jenkins > Managed files > Add a new Config > Maven settings.xml.
It also starts you off with a template so you can just modify what you need. I just added the <localRepository> tag after the commented explanation about it.
Then in your Maven job, choose "provided settings.xml" and select the config file you just created.
Make sure you don't have any overriding options in MAVEN_OPTS and that "Use private Maven repository" is not checked.
PS: It doesn't look like you need to do this with "Global settings.xml" - you can leave that as "Use default". My limited understanding is that the global settings affects all users of the maven system, while the non-global one only affects the user that runs maven. I don't think it matters for most projects, but maybe if you have a special project where some shell execution happens under a different user, this could be important. (I'm just guessing.)