The Ingredients

Jenkins

An extendable open source continuous integration server.

Stackato

The Enterprise Private PaaS that makes it easy to deploy, manage, and monitor applications on any cloud.

Cloud-init

The Ubuntu package that handles early initialization of a cloud instance. It is installed in the Ubuntu Cloud Images and also in the official Ubuntu images available on EC2.

Eucalyptus

Allows you to build production-ready, AWS-compatible private and hybrid clouds by leveraging your existing virtualized infrastructure to create on-demand cloud resource pools.

What happens when you combine all three of these tools?  A potent combination for continuous integration on a easy-to-configure PaaS and an on-premise, AWS-compatible IaaS.  With this combination, developers can take advantage of easy configuration that Stackato brings to the table, running on top of Eucalyptus – bringing an AWS-like cloud environment into your datacenter.

This blog entry will discuss the steps that I took to get Jenkins installed on a Stackato instance store-backed instance running on Eucalyptus.  But before I get started, I would like to thank the folks from ActiveState for all their guidance.  Their support staff is really top notch, and very helpful.  Check them out in #stackato on freenode.net.  They can also be checked out on Twitter at @ActiveState. Now on to the dirty work…..

The Recipe for Success

The Stackato Microcloud Image and Cloud-Init

To begin, the following is needed:

• A running Eucalyptus cloud
• User credentials and proper Eucalyptus IAM policies to allow uploading of images and launching instances. (If there is more information needed here, please check out the Managing Access section in Eucalyptus 3.2 Administrator’s Guide.)
• the Stackato Mircocloud VM for KVM
• A Linux desktop with euca2ools installed.

After downloading the Stackato VM for KVM and unzipping the file, we will need to pull out the root file system, the kernel and ramdisk.  These will be uploaded, bundled and registered as the EMI, EKI, and ERI.  To extract the root filesystem, do the following:

1. Use parted to locate the root filesystem as follows:    

   # parted stackato-img-kvm-v2.6.6.img
   GNU Parted 2.1
   Using /root/images/Stackato-VM/stackato-img-kvm-v2.6.6.img
   Welcome to GNU Parted! Type 'help' to view a list of commands.
   (parted) U
   Unit? [compact]? b
   (parted) p
   Model: (file)
   Disk /root/images/Stackato-VM/stackato-img-kvm-v2.6.6.img: 10737418240B
   Sector size (logical/physical): 512B/512B
   Partition Table: msdos
   
   Number Start End Size Type File system Flags
   1 1048576B 200278015B 199229440B primary ext3 boot
   3 200278016B 1237319679B 1037041664B primary linux-swap(v1)
   2 1237319680B 10736369663B 9499049984B primary ext4
   
   (parted) quit

2. In this example, the root filesystem is partition 2.  The value for “Start” and “Size” will need to be used.  Next, run dd to extract the root filesystem:

   dd if=stackato-img-kvm-v2.6.6.img of=stackato-rootfs.img
    bs=1 skip=1237319680 count=9499049984
   

3. Once it has completed, mount  stackato-rootfs.img to the loopback device:

   mount -o loop stackato-rootfs.img /mnt/

4. Copy out initrd.img-3.2.0-27-virtual  and vmlinuz-3.2.0-27-virtual from /mnt/boot.
5. In /mnt/etc/fstab, replace the UUID entry with LABEL.  The LABEL will look simliar to the following:  

   LABEL=cloudimg-rootfs    /               ext4   defaults     1       1

6. Chroot to /mnt – there may be a need to do a mount -o bind for sys, dev, and proc.
7. Run “dpkg-reconfigure cloud-init”, and make sure that the EC2 Data Source is selected.
8. Unmount stackato-rootfs.img (if sys, dev, and proc were mounted, unmount them before unmounting stackato-rootfs.img).  After it has been unmounted, run tune2fs to change the label of the image:

   tune2fs -L cloudimg-rootfs stackato-rootfs.img

After following these steps, the following should be available:

• initrd.img-3.2.0-27-virtual – to be bundled, uploaded and registered as the ERI
  
• vmlinuz-3.2.0-27-virtual – to be bundled, uploaded and registered as the EKI
• stackato-rootfs.img – to be bundled, uploaded and registered as the EMI

Go through the steps of bundling, uploading and registering the ERI, EKI, and EMI.  For additional information, please refer to the Add an Image section of the Eucalyptus 3.2 User Guide.

Launching the Stackato Image

Now its time to launch the Stackato image on Eucalyptus.  Since cloud-init has the enabled EC2 data source now, when the image is launched, the instance will grab ssh keys, and mount the ephemeral storage.  Also, additional configuration can be passed using the user-data file option.  More information regarding this can be found on Stackato’s documentation in reference to using cloud-init.  Key thing to remember here is that the minimum RAM requirement for the Stackato image is 2 gigs.  Make sure the VM type used for launching the Stackato image has at least 2 gigs of RAM or more.  In this example, the image ID is emi-DAB23A8A.  The ramdisk and kernel are registered as eri-9B453C09 and eki-ADF640B0.   The VM type c1.xlarge is used, which has 4 CPU,  4096 MB of RAM,  and    50 Gigs of disk space.

euca-run-instances -k admin emi-DAB23A8A -t c1.xlarge 
--kernel eki-ADF640B0 --ramdisk eri-9B453C09

Use euca-describe-instances to check to see when the instance reaches a running state:

euca-describe-instances i-100444EF
RESERVATION r-CC69438B 345590850920 default
INSTANCE i-100444EF emi-DAB23A8A euca-192-168-55-104.wu-tang.euca-hasp.eucalyptus-systems.com 
euca-10-106-101-17.wu-tang.internal running admin 0 c1.xlarge 2013-02-23T00:34:07.436Z enter-the-wu eki-ADF640B0 
eri-9B453C09 monitoring-disabled 192.168.55.104 10.106.101.17 instance-store

The key thing for running a Stackato instance is setting up the correct DNS entries.  For more information regarding setting up DNS with regards to a Stackato instance, please read the Detail Configuration section on DNS in the Stackato online documentation.  For this example, instead of using an external DNS service using a tool like nsupdate, to configure the A record and CNAME records, we will use xip.io. xip.io is a magic domain name that provides wildcard DNS for any IP address.  Next, its time to configure the Stackato instance.

Configuration of the Stackato Instance

To configure the Stackato instance, do the following:

1. SSH into the instance.  

   ssh -i creds/admin.priv 
   stackato@euca-192-168-55-104.wu-tang.euca-hasp.eucalyptus-systems.com

2. Make note of the ip address associated with eth0 and the netmask using ifconfig.  Also note the gateway IP by using the route command.
3. Run “kato op static_ip” to configure the static IP address for eth0.  Make sure and add 127.0.0.1 as the first entry as part of the nameservers, and add “containers.” as the first entry under the search domains.
4. Run “kato rename public DNS name “, where public DNS name includes the public IP of the instance, using xip.io (e.g. 192.168.55.104.xip.io)
5. Run “kato disable mdns”, then run “sudo reboot” to reboot the instance.
6. Once the instance has come back up, ssh into the instance, and run the following command  ”kato setup core api.public DNS name” where public DNS name is the same value used for the “kato rename” step (e.g.  192.168.55.104.xip.io).
7. Next, edit /etc/resolv.conf and make sure that the value for the search option is “containers.”, and the first entry for the nameservers is 127.0.0.1.
8. Finally, run “kato enable –all-but mdns”

Thats it!  Now go to the public DNS name that was used in your favorite browser.  For this example, 192.168.55.104.xip.io was used.  The following landing page should look similar to what you see here in the Stackato documentation regarding accessing the instance through the management console.

Setting Up Jenkins

After setting up the admin account, navigate to the “App Store” on the lefthand menu.  Once selected, navigate to find the Jenkins application:

Jenkins Application

After selecting to install Jenkins, select “Yes” to install.  After the installation takes place,  select “Applications” in the left hand menu.  From there, select the Jenkins application, and select “Start” (its the green arrow to the right of the application window).   Once it has started, you will see the following:

Jenkins Running in Stackato

Now Jenkins is ready to be used.

If anyone wants to test this out on Eucalyptus but doesn’t have access to their own Eucalyptus cloud, fear not, the Eucalyptus Community Cloud has the Stackato image available.  After applying to get access to the Community Cloud, follow the steps above.  The image for Stackato is as follows:

IMAGE emi-859B3D5C stackato_v2.6.6/stackato-cloudinit.manifest.xml 150820662310 available public x86_64 machine eki-6FBE3D2D eri-67463B77 instance-store

And as always, this image and steps can be used on AWS EC2 as well.

Let me know if there are any questions.  Feedback is always welcome.  Enjoy!