Infraestructure as a Service key technologies

There is a lot of things happening around cloud computing (a lot more to come I hope). Infraestructure as Service (IaaS) is one of the things. Cloud computing is not only IaaS but it is also Software as a Service (SaaS) and also Platform as a Service (SaaS).

A SaaS example would be gmail or salesforce. That is a software we access from our browser but we do not know were it is.

A PaaS example would be the Google App Engine. In Google App Engine we have a platform ready to be used to create our own applications, applications like gmail that then would be used as SaaS.

An IaaS example would be Amazon. We can create virtual images there, use storage, get an IP address, ... and then we are invoiced for the usage of that (CPU, bandwith, Hard disc).

Using IaaS we can have PaaS for our developers and SaaS for our end users, so for me, IaaS is the key technology for cloud computing.

But, which are the key technologies on IaaS that are playing an important role?

In my opinion, those technologies are:

1- Virtualization. That is the first technology that would come to my mind. We have different hypervisors: Xen, KVM and vmware.

2- JeOS. Just Enough Operating System. Once we have virtualization into play, we need and OS to create virtual images. JeOS are minimum operating systems. LimeJEOS would be an example, the openSUSE JeOS.

3- Software appliances. But what we do with virtual images with JeOS? We can build software appliances. For example a zimbra software appliance, so we have something like the gmail but on an appliance that can be installed and moved to any server that has the right hypervisor. But in which format will be create the appliance? vmware, xen, kvm? Let's create an xml description of what we want, so we can build it in any. That is what KIWI does.

4- Software appliances management. Ok. We have the appliance. What we want to manage that appliance. Set the root password, configure the network, timezone,.... so we need an interface to manage that. For example WebYaST and openwbem. WebYaST is a web interface for managing suse appliances and openwbem is the CIM implementation as a REST API.

5- Update Server. Experience tell us that, once you have done an appliance, you should not update the appliance from different update servers, but usually your appliance will have some software that does not come from openSUSE. For example, if you built a zimbra appliance, you will for sure want the latest zimbra on a stable openSUSE, but the stable openSUSE won't have that version, so you will install zimbra from source. So you need to update both openSUSE and zimbra. That is the reason why you need an update server that merges both updates and distributes those to your appliances. Proxy repo does that.

6- vpn. Virtual private networks. On a cloud, you may not have all the appliances on the same network but you want them to behave like that. By using openvpn, you can have appliances on different networks (and different hypervisors) and they will behave like they are at the same network. Moreover, if you migrate them, they will still have the same ip adress.

7- SSO. Single sign on. Ok. You have different appliances and you provide SaaS to different software. You will for sure will like your users to not have to identify on each application with a different user, will you? So you need a single sign on, like openID or CAS.

8- Management interface for the cloud. The cloud needs a management interface that let you create, destroy, migrate, etc. For example amazon has its own interface, as well as vcloud. We have also opensource solutions like eucalyptus, open nebula and abiquo.

For sure there are more technologies involved on IaaS but in my opinion those 8 are the key ones. Of course would be great to read your comments specially if you disagree.