This chapter documents the command line tools available for interacting with the CERN cloud. These tools are intended for the more experienced users, especially on a Linux platform. For occasional use, the dashboard approach is simpler as documented in Tutorial using a browser.
There are three primary sets of tools available from the command line on a Linux system.
- The unified OpenStack client (openstack). Most of the examples given in this book are based on this command.
- OpenStack tools (nova, glance) which provide the lowest level access to the OpenStack interfaces.
- Eucalyptus EC2 tools (euca2ools) as often used with the Amazon public cloud
We recommend to use these interfaces on the
lxplus-cloud cluster, a CC7-subset of lxplus with the most recent OpenStack clients. There are also versions available for standalone Mac, Windows and Linux machines.
The tools can be compared as follows:
In general, if you are looking for an environment which is like a physical box registered on the CERN network, the unified openstack CLI is probably the most appropriate tool. If you are looking for a single set of tools which could also run on EC2 clouds such as Amazon, euca2ools can be used (or one of the programming APIs listed in the advanced section).
Note: Some EC2 functions in euca2ools do not work on OpenStack. The validated commands are listed here.
|Feature||Unified CLI||Other OpenStack CLIs||Euca2ools|
|Allows you to choose the hostname of your VM||Yes||Yes||No|
|Compatible with non-OpenStack clouds||No||No||Yes|
|Time to create a virtual machine||Default is 1-10 minutes waiting for DNS update. Options for faster creation are available in creation time properties.||As unified CLI||1 minute|
|DNS Entry||Yes||Yes||No - IP Address is allocated, DNS name cannot be changed|
|Kerberos Server Tab (so you can use AFS or Windows services)||Yes||Yes||No|
|X.509 Host Certificate||Yes||Yes||No|
|Contextualisation using cloud-init or amiconfig||Yes||Yes||Yes|
|Outgoing connectivity (i.e. can connect to services on the Internet and LCG networks)||Yes||Yes||Yes|
|Incoming Services (i.e. can support users outside of CERN trying to access the services on the VM)||Not by default but can be requested through LanDB||As for unified CLI||Not by default and not recommended.|
|Supports X.509 or Kerberos client authentication||Yes||No||No|
The detailed functionality can be found in the OpenStack documentation