Brew Jenkins

Posted on  by admin

So, what if you want to run jenkins locally on a mac? What if you want it to build from a private github repository, and you want it to use its own private key? And you’re on a mac?

Get Jenkins

First, you need to get jenkins. On my homebrew-enabled mac, I ran brew install jenkins. Without homebrew, you can just download the latest war file. (You will need java 6 to run jenkins.) Homebrew provides a plist for launching jenkins when you log in. If that’s adequate, then you can stop reading.

The first 1000 people who click the link will get 2 free months of Skillshare Premium: This video was sponsored by Skillsha. Homebrew ships with a whole bunch of commands that don’t show up in brew -help. You can see a list of them in the Homebrew git repo. Each file is named like brew-COMMAND, and you run them with brew command. I recommend brew beer. What’s next If you liked this, I recommend reading through Homebrew’s Tips and Tricks.

Brew Jenkins County

Create a service account

Next you need to create a user to run jenkins. This is the most challenging part of the process. (I used a script from a pastebin as reference.) Here’s what I did:

Before I ran through that, I did check that the ids were available. You can search for users with dscl . -search /Users uid 600 and groups with dscl . -search /Groups gid 600.

Brew jenkins county

Also, I don’t think the uid and gid need to be the same, but most of the builtin service accounts (e.g. jabber) are, so I just went along with it.

Create the daemon

Mac OS uses launchd to control daemons and agents. It’s pretty easy to create a launch daemon. Create the file /Library/LaunchDaemons/org.jenkins-ci.plist with the following content, based on the plist from the homebrew jenkins formula. You may need to update the version number in the ProgramArguments.

I think I had to load the daemon (sudo launchctl load /Library/LaunchDaemons/org.jenkins-ci.plist). Rebooting should work, too.

Create an ssh key

Like I said, I wanted jenkins to have its own ssh identity. This is fairly easy: sudo -u jenkins ssh-keygen

The new key is in /var/jenkins/.ssh/ and can be copied to github, or wherever you have your source code.

Set up a build

Now you need to configure jenkins. Open http://localhost:8080/, click “Manage Jenkins”, “Manage Plugins”, then “Available”. I installed the git and github plugins. The git plugin gives you basic git functionality. The github plugin gives you links from the build info pages to github commit pages. After the install is complete, click the “Schedule a restart” button.

After jenkins restarts, configure git. From the “Manage Jenkins” page, “Configure System” and make sure the path for git is right. (It wasn’t for me: /usr/bin/git is the default, but homebrew put it in /usr/local/bin/git.)

Brew Jenkins Config

Now, you can create your project. The rest of this post is a description of how I set up the build for my rails 3.0 project.

Click “New Job” in the menu on the left. Choose the “free-style” option. On the configuration page, set the github url prefix (e.g. Set the source code as git, with the repo url (e.g. [email protected]:user/project.git; if your url starts with git:// or http://, then you probably don’t need to do the ssh key stuff earlier). I set branches to build to “master”, but leaving it blank is sometimes useful. I chose to Poll SCM, with a schedule of “* * * * *”, though I didn’t set that up until after I had the build mechanics set up right.


The only build step is to execute a shell. Here’s what I’m using. There are a few things to note here. I’m using a system-installed rvm, so all the ruby commands are run through it. Jenkins can collect JUnit test results and produce some trend graphs, so I use the ci_reporter gem’s ci:setup:testunit to format the results JUnit-style.