Where does Jenkins store configuration files for the jobs it runs?

Jenkins stores some of the related builds data like the following:

• The working directory is stored in the directory {JENKINS_HOME}/workspace/.

  • Each job store its related temporal workspace folder in the directory {JENKINS_HOME}/workspace/{JOBNAME}

• The configuration for all jobs stored in the directory {JENKINS_HOME}/jobs/.

  • Each job store its related builds data in the directory {JENKINS_HOME}/jobs/{JOBNAME}

  • Each job folder contains:

    • The job configuration file is {JENKINS_HOME}/jobs/{JOBNAME}/config.xml

    • The job builds are stored in {JENKINS_HOME}/jobs/{JOBNAME}/builds/

See the Jenkins documentation for a visual representation and further details.

JENKINS_HOME
 +- config.xml     (jenkins root configuration)
 +- *.xml          (other site-wide configuration files)
 +- userContent    (files in this directory will be served under your http://server/userContent/)
 +- fingerprints   (stores fingerprint records)
 +- nodes          (slave configurations)
 +- plugins        (stores plugins)
 +- secrets        (secretes needed when migrating credentials to other servers)
 +- workspace (working directory for the version control system)
     +- [JOBNAME] (sub directory for each job)
 +- jobs
     +- [JOBNAME]      (sub directory for each job)
         +- config.xml     (job configuration file)
         +- latest         (symbolic link to the last successful build)
         +- builds
             +- [BUILD_ID]     (for each build)
                 +- build.xml      (build result summary)
                 +- log            (log file)
                 +- changelog.xml  (change log)

On Linux one can find the home directory of Jenkins looking for a file, that Jenkins' home contains, e.g.:

$ find / -name "config.xml" | grep "jenkins"
/var/lib/jenkins/config.xml

Jenkins 1.627, OS X 10.10.5 /Users/Shared/Jenkins/Home/jobs/{project_name}/config.xml

The best approach would be to keep your job configurations in a Jenkinsfile that live in source control.

For the sake of completeness: macOS High Sierra, Jenkins 2.x, installation via Homebrew
~/.jenkins/jobs/{project_name}/config.xml

Complete overview about jenkins home: https://wiki.jenkins.io/display/JENKINS/Administering+Jenkins