Let's tackle the first problem. How do you spin up a Linux 7 - 3.10 kernel in the Oracle Compute Cloud Service? If we look at the compute instance creation we can see what images that we can boot from.
There is not Linux 7 - 3.10 kernel so we need to download and import and image that we can boot from. Fortunately, Oracle has gone through a good importing a bootable image tutorial. If we follow these steps, we need to first download a CentOS 7 bootable image from cloud.centos.org. The cloud instance that we use is the CentOS-7-x86_64-OracleCloud.raw.tar.gz. We first download this to a local directory then upload it to the compute cloud image area. This is done by going to the compute console and clicking on the "Images" tab at the top of the screen.
We then upload the tar.gz file that is a bootable image. This allows us to create a new storage instance that we can boot from. The upload takes a few minutes and once it is complete we need to associate it with a bootable instance. This is done by clicking on the "Associate Image" button where we basically enter a name to use for the operating system as well as description.
Note that the OS size is 9 GB which is really small. We don't have a compute instance at this point. We either need to create a bootable storage element or compute instance based on this image. We will go through the storage create first since this is the easiest way of getting started. We first have to change from the Image tab to the Storage tab. We click on the Create Storage Volume and go through selection of the image, storage name, and size. We went with the storage size rather than resizing the storage we are creating.
At this point we should be able to create a compute instance based on this boot disk. We can clone the disk, boot from it, or mount it on another instance. We will go through and boot from this instance once it is created. We do this by going to the Instance tab and clicking on Create Instance. It does take 5-10 minutes to create the storage instance and need to wait till it is completed before creating a compute instance. An example of a creation looks like
We select the default network, the CentOS7 storage that we previously created, the 2016 ssh keys that we uploaded, and review and launch the instance.
After about 15 minutes, we have a compute instance based on our CentOS 7 image. Up to this point, all we have done is create a bootable Linux 7 - 3.10 kernel. Once we have the kernel available we can focus on connecting and installing the cloud storage appliance software. This follows the making backup better blog post. There are a couple of things that are different. First, we connect as the user centos rather than oracle or opc. This is a function of the image that we downloaded and not a function of the compute cloud. Second, we need to create a second user that allows us to login. When we use the centos user and install the oscsa_install.sh script, we can't login with our ssh keys for some reason. If we create a new user then whatever stops us from logging in as the centos user does not stop us from logging in as oracle, for example. The third thing that we need to focus on is creating a tunnel from our local desktop to the cloud instance. This is done with ssh or putty. What we are looking for is routing the management port for the storage appliance. It is easier to create a tunnel rather than change the management port and opening up the port through the cloud firewall.
From this we execute the commands we described in the maker backup better blog. We won't go through the screen shots on this since we have done this already. One thing is missing from the screenshot, you need to disable selinux vy editing /etc/sysconfig/selinux. You need to disable SELINUX by editing the file and rebooting. Make sure that you add a second user before rebooting otherwise you will get locked out and the ssh keys won't work once this change is made.
The additional steps that we need to do are create a user, copy the authorized_keys from an existing user into the .ssh directory, change the ownership, and assign a password to the new user, and add the user to /etc/sudoers.
cp ~centos/.ssh/authorized_keys ~oracle/.ssh
chown -R oracle ~oracle
At this point we should be able to spin up other compute instances and mount this file system internally using the command
mount -t nfs -o vers=4,port=32770 e53479.compute-metcsgse00028.oraclecloud.internal:/
In summary, we did two things in this blog. First, we uploaded a new operating system that was not part of the list of operating systems presented by default. We selected a CentOS instance that conforms to the requirements of the cloud storage appliance. Second, we configured the cloud storage appliance software on a newly created Linux 7 - 3.10 kernel and created a putty tunnel so that we can manage the directories that we create to share. This gives us the ability to share the object storage as an nfs mount internal to all of our compute servers. It allows for things like spinning up web servers or other static servers all sharing the same home directory or static pages. We can use these same processes and procedures to pull data from the Marketplace and configure more complex installations like JD Edwards, PeopleSoft, or E-Business Suite. We can import a pre-defined image, spin up a compute instance based on that image, and provision higher level functionality onto infrastructure as a service. Up next, platform as a service explained.