5.4. Openstack Horizon¶

5.4.1. Managing Virtual Machine Instances¶

One of the main activities you’ll be performing in this web interface is the management of virtual machines, or instances. You do this via the Instances page that is reachable from the menu in the lower left of the Overview page. An example Instances page is shown below. For instances that you have running, you can click on the name of the instance to get more information about it and to access the VNC interface to the console. The dropdown menu to the left of the instance lets you perform a variety of tasks such as suspending, terminating, or rebooting the instance or associating a floating IP address with the instance (see below).

The Instances page also lets you create new virtual machines by using the ‘Launch Instance’ button in the upper-right. When you click this button, a dialog window pops up. In the first ‘Details’ tab, you select the source of the instance, which is either an ‘Image’ or a ‘Snapshot’ (an image created from a running virtual machine). If you select ‘Image’, the Image dropdown presents a list of virtual machine images that we have provided, that other FutureGrid users have uploaded and made public, or images that you have uploaded for yourself. If you select ‘Snapshot’, the Image dropdown presents a list of virtual machine images that you have created from your running virtual machines.

On the Details tab, you also provide a name for this instance (to help you identify instances that you are running), and select the amount of resources (Flavor) to allocate to the instance. If you select different flavors from the Flavor dropdown, their characteristics are displayed on the right.

The next tab is ‘Access & Security’ where you select an ssh keypair that will be inserted into your virtual machine. These keypairs are synchronized with the keypairs you have in the FutureGrid portal and you should manage your keypairs there, rather than in this OpenStack web interface. You will need to select a keypair here to be able to access an instance created from one of the public images FutureGrid provides. These images are not configured with a default root password and you will not be able to login to them without configuring an ssh key.

The final tab that you’ll need to use when launching an instance is the Networking tab. You will need to select the ‘private’ network, even though there is currently no other option. Once you do this, you can Launch your instance and the Instances page will show progress as it starts.

5.4.2. Snapshots¶

The instance list page shown above has an option ‘Create Snapshot’ that allows you to save a copy of the disk contents of a running virtual machine. This allows you to start new virtual machines in the future that are identical to this one and is an easy way to save any changes you make to a running virtual machine.

An important note is that for CentOS 6 images, you should run a command in the VM before taking a snapshot so that the snapshot will start correctly. The step is to simply execute:

$ rm /etc/udev/rules.d/70-persistent-net.rules

and the reason why this is needed is described in /root/README_snapshot.txt in the virtual machine image.

5.4.3. Floating IP Addresses¶

The private network above assigns an IP address to each virtual machine that is only valid within the cluster. These virtual machines can be ssh’ed to from the login node and can be accessed using VNC in the OpenStack web interface. In addition, these virtual machines can contact systems on the Internet via a NAT mechanism provided by OpenStack.

If you want your instances to be reachable from the internet, you will need to associate a public IP address to them. This is accomplished in two steps. The first step is to allocate a floating IP address to your project using the ‘Access & Security’ page reachable from the bottom-left menu.

At the top of this page, you can allocate and deallocate floating IP addresses, which are public IP addresses reachable from outside systems. When you allocate an IP address, the dialog below appears. There is currently only one floating IP pool (‘public’) to allocate from, so you just select ‘Allocate IP’.

After you have an available floating IP address, the second step is to allocate it to a running virtual machine. You can do this either via the drop down menu to the left of the IP address in the page above or via the drop down menu to the right of the virtual machine on the Instance page.

5.4.4. Accessing Your Virtual Machine¶

There are two ways you can access your virtual machine. One way is you can access the console using Virtual Network Computing (VNC) in the OpenStack web interface. If you navigate to the Instances page using the left menu and select your instance, you will see a tab VNC that has this console.

The second way is via ssh. When you created your virtual machine, you specified an ssh key to load in to the VM. OpenStack injects this ssh key into the VM and you can use the corresponding private ssh key to login to the VM. You will need to either ssh -Ato alamo.futuregrid.org and then to the private IP of your VM or you will need to associate a floating, public IP to your VM and you can then ssh directly to your VM using this public IP from anywhere.

An important note is that many of the images that we provide do not allow you to ssh into the root account. Instead, you ssh into a different account and use passwordless sudo for any administrative tasks. For Ubuntu images, you ssh in to the ‘ubuntu’ account. For CentOS and Fedora 18 and older Fedora images, you ssh in to the ‘ec2-user’ and for Fedora 19 and newer, you ssh in to the ‘fedora’ user.

5.4.5. Uploading an Image¶

As you saw above, FutureGrid provides a number of generic Linux images that you can customize for your needs. However, you may wish to use a different Linux distribution than we provide or you may have an existing image that you want to use. In this case, you can upload your image using the web interface.

There are two steps to uploading an image. The first step is to make the image available via HTTP and the second is to instruct OpenStack to download that image. If your image is not already available via HTTP, a simple way to do this is to use an HTTP server that is provided as part of Python. When you start this server from a directory, it provides access to all files in that directory. You can:

$ ssh alamo.futuregrid.org ... alamo$ mkdir /N/work/$USER/images alamo$ cd /N/work/$USER/images # place your image(s) into this directory alamo$ python -m SimpleHTTPServer 8002 Serving HTTP on 0.0.0.0 port 8002 ... Next, in the OpenStack web interface, navigate to “Images and Snapshots” in the left menu. In the upper right of that page, you will see a button “Create Image”. Click on that button and fill out the dialog similar to below.

Create An Image The Name is the human-readable name you want to display for this image. The location is where OpenStack should retrieve the image from. In this example, that location is our SimpleHTTPServer on port 8002 of alamo.futuregrid.org. The path in the location URL is the relative path to the image from the directory that you ran SimpleHTTPServer out of. The format is the type of image file you are uploading. The minimum disk and minimum RAM are the minimum amount of each that this virtual machine image needs to be able to run. These are optional and you do not need to specify them if this image can run in the smallest VM flavor (m1.tiny). Finally, you can have the image be available to all users or not. Once you finish filling out this form, click “Create Image” and you should see OpenStack access your HTTP server and then this image will be included in your list of images in OpenStack.

Once your image has been uploaded, Ctrl-C your Python SimpleHTTPServer to stop it.

5.4.6. Managing Volumes¶

OpenStack supports the creation of volumes that are independent of instances and images. These volumes are managed via the ‘Volumes’ page that is accessible via the lower-left menu.

The general process is to create a volume, attach that volume to a running instance, mount the volume in the instance, format the volume, use the volume in the instance, and then detach the volume. The data in the volume will be available to whatever instance you attach it to in the future.

An important note is that a volume can only be attached to one instance at a time so it cannot be directly used as, say, a shared filesystem among your instances.

5.4.7. EC2 Interface¶

OpenStack on Alamo and Hotel supports the EC2 interface for programmatic access. You can download your EC2 credentials from the web interface via the Settings link in the upper-right of any page and then ‘EC2 Credentials’ in the lower-left menu. Note that you have different EC2 credentials for each FutureGrid project you participate in. If you are a member of multiple FutureGrid projects, we request that you use the corresponding EC2 credentials when starting virtual machines for a project.

Note that the S3 interface is not currently available since the OpenStack Swift object store has not been deployed on Alamo at this time.

5.4.8. OpenStack REST Interfaces¶

The OpenStack REST Interfaces are not currently supported on Alamo and Hotel. It is non-trivial to enable secure connections for these interfaces on both the client and the server side and the EC2 interfaces support almost all of the user-facing functionality of the native OpenStack interfaces. Login or register to post comments