Guide to Installing and Configuring Jenkins CI on macOS

Installation

To install Jenkins on a Mac, first ensure JDK is installed and then run the Homebrew command:

brew install jenkins

The package is placed under /usr/local . Homebrew provides instructions to create a launch agent:

ln -sfv /usr/local/opt/jenkins/*.plist ~/Library/LaunchAgents
launchctl load ~/Library/LaunchAgents/homebrew.mxcl.jenkins.plist

Instead of symlinking the plist, copy it to avoid losing changes after Homebrew upgrades. Pin the formula to prevent automatic upgrades:

brew pin jenkins

You can start and stop Jenkins manually:

# Start.
launchctl load ~/Library/LaunchAgents/homebrew.mxcl.jenkins.plist

# Stop.
launchctl unload ~/Library/LaunchAgents/homebrew.mxcl.jenkins.plist

Configuration

Running the server reveals memory‑related errors; adjust the JVM options in the launchd plist. Set a 64‑bit model, initial and maximum heap size, and enable a concurrent garbage collector.

<string>-d64</string>
<string>-Xms512m</string>
<string>-Xmx512m</string>
<string>-XX:+UseConcMarkSweepGC</string>
<string>-XX:+CMSClassUnloadingEnabled</string>
<string>-XX:MaxPermSize=256m</string>

HTTP Proxy

If a corporate proxy is required, add the proxy host and port options:

<string>-Dhttp.proxyHost=my-company-proxy-host.com.au</string>
<string>-Dhttp.proxyPort=8080</string>

Port and Prefix

Run Jenkins on a custom port (default 8080) with a URL prefix such as /jenkins . These arguments are passed to jenkins.war located in /usr/local/opt/jenkins/libexec :

<string>-jar</string>
<string>/usr/local/opt/jenkins/libexec/jenkins.war</string>
<string>--httpListenAddress=127.0.0.1</string>
<string>--httpPort=8080</string>
<string>--prefix=/jenkins</string>

Run at Load

Enable automatic start after reboot by setting RunAtLoad to true in the plist:

<key>RunAtLoad</key>
<true/>

Environment Variables

Define any required environment variables, for example the HTTP proxy:

<key>EnvironmentVariables</key>
<dict>
  <key>HTTP_PROXY</key>
  <string>http://my-company-proxy-host.com.au:8080</string>
</dict>

Standard Output and Error

Redirecting stdout/stderr is optional; the author advises against redirecting stderr to a file due to large log growth.

StandardErrorPath
/Users/i4niac/.jenkins/log/error.log

Jenkins stores its files under the .jenkins directory in the user’s home folder; ensure a log subdirectory exists.

Full Configuration

The complete launchd plist combines all the above settings:

<?xml version="1.0" encoding="UTF-8"?>

With this configuration, Jenkins runs continuously and can reliably execute CI jobs.

Tips

To verify how Jenkins was started, inspect the process list:

ps aux | grep java

The output shows the Java command line with all JVM options and the path to jenkins.war . After installation, further steps such as installing plugins, configuring SSH keys for Git, and other management tasks are required to fully operationalize the CI server.