I’ve been looking around for a good Continuous Integration service that doesn’t just support GitHub. GitHub is great and I use it for all of my hosting all of my open source projects, it’s just I use Codebase for all of my private & client projects.
I’ve had issues in the past setting up Jenkins mainly due to there being no good tutorials out there for setting it up properly for testing Rails projects. So here I am with a post on how I have it installed & setup.
In this post, I’m using a new DigitalOcean server with Ubuntu 12.04 x86 (32 bit). I’m running most (unless stated) of the commands as root.
The first thing to do when creating the server is to update it.
Once the server has been updated, now it’s time to install other programs such as MySQL and some utilities.
To install MySQL, run this command. It’s recommended that you set a password when it asks.
I’ve created an account called builds with no password but with the following global permissions.
We can now continue with the install of Jenkins.
To install Jenkins, we need to add the repoisitory to our apt-get sources.
This may take a while to install.
Once it’s installed you should now be able to run Jenkins by running this command.
You can then access the server at http://YOUR-IP:8080.
If that doesn’t load for you, it may be that your server doesn’t have enough RAM or the max RAM hasn’t been set in the Jenkins config file.
tail the log to find out why it’s not starting. I like to keep another terminal tab open with this command running while setting the server up.
On my server, I’m getting this error which means that Jenkins is using too much RAM.
Exception in thread "RequestHandlerThread[#1]" java.lang.OutOfMemoryError: Java heap space
To rectify this, stop the Jenkins server and edit the Jenkins config file.
Once the config file is open, you should see the following options
The option we want to change is
#JAVA_ARGS="-Xmx256m". Remove the comment (
#) from the start of that command and that should be it. In my case I had to change the
Close & save the file and start the server up again.
If you are
tailing the log at the same time, then you should see this
You should now be able to access the server at http://YOUR-IP:8080.
That’s Jenkins installed. Now to configure it.
OK, at the moment we now have Jenkins installed and accesible through the web browser on port 8080. Now let’s setup Nginx so the site can be accessed without the port 8080.
Once Nginx is installed, we need to create a ‘site’ for it so Nginx knows what we want to do.
Create a file at
/etc/nginx/sites-enabled/jenkins and paste the following code in, changing anything necessary:
Once the file is created, restart Nginx and you should be able to access Jenkins without a port. You may have to remove the default site, if so run
You should now be able to access Jenkins on http://YOUR-IP or http://YOUR-HOSTNAME
RVM is great for installing and using multiple versions of Ruby on one machine.
Before we can install it, a password needs to be set on the
jenkins account and the account needs to be part of the
Now we can login to the
jenkins account and install RVM under that user.
The command above installs RVM and installs the latest Ruby version, which in this case, is 2.1.1.
If you’ve not used RVM before, it’s very easy to install different Ruby versions and use them. For example, if I wanted to install Ruby 1.9.3, I would run
rvm install 1.9.3. It’s that easy.
Then to use Ruby 1.9.3, you run
rvm use 1.9.3.
If you wanted to set Ruby 1.9.3 as the default version, then
rvm use 1.9.3 --default.
On my server, I’ve installed Ruby 2.1.1, 2.0.0 and 1.9.3.
SSH / Git
While we are still logged into the
jenkins account, we can setup some SSH keys for this user so we can easily & securely connect to Git repos.
Copy that SSH key and paste it as an SSH key in GitHub or Codebase and you’ll then have access to that repository.
You can now log out of the
jenkins account as we don’t need to be logged in anymore by typing
exit and hitting enter.
Jenkins Setup & Plugins
Now Jenkins is installed, we can add some plugins to enhance the setup & usage of the server.
On the left hand side, click on
Manage Jenkins then
Manage Plugins. There may be some updates available. Check all of the plugins in the
Updates tab and then
Install without restart. You will be taken to a page showing the progress of the install/update.
Once they’ve been updated, go back to the Manage Plugins page and choose the
Available tab. Because this page is very long, I normally
CTRL+F to find the plugin I’m looking for.
In the list, select the following and hit the
Install without restart button:
- Git plugin
- GitHub plugin
- RVM plugin
- Green Balls
Check the box at the bottom of the page that says
Restart Jenkins. Some plugins require Jenkins to be restarted in order to work properly, however, most plugins work fine without a restart. It will show when Jenkins needs to be restarted, like below.
We are now ready to create out first Jenkins project.
Go back to the home page and click on
New Item in the sidebar on the left. You will be asked for a name and a few select options.
Build a free-style software project option.
After creating the project, you will be redirected to the configuration page where you can change the name, the repo settings and more.
We want to change the GIT repo so select the
Git option and paste the URL of your GIT repo.
If you get an error like this, then you need to login to the
jenkins account again and verify that you can connect to that host’s server over GIT. In my case, I’m using Codebase so I had to run
ssh email@example.com and just type
Once that’s done, enter the repo again and that error should disappear. If there’s no error, that means it can successfully connect to the repo.
Scroll down and check the
Run the build in a RVM-managed environment and type the Ruby version and gemset name (if you want). I normally use
2.0.0@app_name. That way it keeps gems separate to each app that I want to test on my Jenkins server.
Now we need to create a ‘build step’. This runs commands that test your app. In this case, choose the
Execute shell option and paste the following into the text box provided. Change the
my_project_test to the database of your project.
Save and then
Build Now in the sidebar. This will start a build of your project. You will see the
Build History table populate. Click on the date and you will be taken to that build. Click on the
Console Output option in the sidebar to see a live console of the build taking place.
On each build,
bundle install is run so you need to be sure that all the necessary pre-reqs are installed for your project.
In order to fix this, I’ll install NodeJS using thw following commands
Now NodeJS is installed, I’ll run the build again by clicking the
Back to project then
Build Now button in the sidebar. Again, click the date and then on
Now that Jenkins is setup and working, how will you know if a build fails?
In this example, I’m going to setup email notifications. I use Postmark for most of my outgoing email from apps so all I need is the SMTP server and username/password.
From the home page, click on
Manage Jenkins then
Configure System. Scroll down and you’ll see an
E-mail notification option. Fill out the
SMTP server, which in my case is
If your SMTP server requires authentication, which most do, click on the
Advanced button and enter the username and password in the required fields. To check it’s all working ok, check the
Test configuration by sending test e-mail box and enter your email address. Click the
Test configuration button and if everything is ok, you should receive a test email from Jenkins.
Go back to your project and then
Configure. Scroll down to the bottom to
Post-build actions. These are scripts/actions that run when a build has finished, whether it passed or failed. Click the
Add post-build action button and choose
E-mail notification. You’ll have a field to enter an email address to notify. Checking the
Send separate e-mails to individuals who broke the build box will send an email to the person who last commited and broke the build.
That’s it, you’ve not got a Jenkins CI server up and running running Ruby on Rails tests!