[[PageOutline]]

= How to Instsall geni-lib =

[https://bitbucket.org/barnstorm/geni-lib/src geni-lib] is a python library written by Nick Bastin of Barnstormer Softworks. It can be used to create RSpec file for large topology. In this page, we show how to install and configure geni-lib, and show some examples of using geni-lib. The installation and configuration of geni-lib has been tested on MacOS 10.9.3, and python27 installed from !MacPort is set to be the default python. 

To use geni-lib, you will first need to download it from the [https://bitbucket.org/barnstorm/geni-lib/src geni-lib repository].


 
== Download geni-lib ==

For MacOS Experimenters:

 * Install Mercurial 
   * If you are using !MacPort, you can Install mercurial with 
{{{
sudo port install mercurial
}}}
   * You can also find the Mercurial download page [http://mercurial.selenic.com/downloads here]

 * Configure Mercurial
   * Create .hg file under ~/.
{{{
[ui]
username = Your User Name <xxx@xxx.xxx>
}}}

 * Clone geni-lib
{{{
hg clone https://bitbucket.org/barnstorm/geni-lib
}}}

 * Check and Pull Update
{{{
hg pull && hg update default
}}}



Once you have downloaded the geni-lib to your local machine, you will see two directories under ./geni-lib/
{{{
dhcp89-69-127:geni-lib xliu$ ls
geni	samples
}}}

The directory "geni" is the library for RSpec generation and other purposes, and "samples" contains examples of using the library, as well as a sample configuration file that you need to modify it before writing and  testing your scripts.


== Download Dependencies and Configure PYTHONPATH ==

In the system that has been tested, a python package lxml is needed for geni-lib.

 * Install lxml python packages
 
 If you are using !MacPort, install lxml using 
 {{{
 $ sudo port install python27-lxml
 }}} 

 * Add PYTHONPATH:

 For MacOS experimenters, you can add following lines to the end of your ~/.profile
 {{{
 # add python path
 export PYTHONPATH=$PYTHONPATH:<your path to geni-lib>
 }}}
 Then, run 
 {{{
 source ~/.profile
 }}}

  * Optional Step: Switch Python Version
  
 Sometimes you may have problems with python versions if you have two different versions of python installed. If you installed python27 and python modules from !MacPort, so you may need to select python27 installed by !MacPort as your default python. 
{{{
$ sudo port select --set python python27
}}}


== Configure geni-lib ==

 * Modify the configuration file

 To use geni-lib, you will need to create a configuration file that contains your credential to GENI and other information about your experiments. Go to ./geni-lib/samples/, and open the file 

 {{{
dhcp89-69-127:samples xliu$ cat example_config.py
from geni.aggregate import FrameworkRegistry
from geni.aggregate.context import Context
from geni.aggregate.user import User

def buildContext ():
  portal = FrameworkRegistry.get("portal")()
  portal.cert = "/home/nbastin/.ssh/portal-nbastin.pem"
  portal.key = "/home/nbastin/.ssh/portal-nbastin.key"

  nbastin = User()
  nbastin.name = "nbastin"
  nbastin.urn = "urn:publicid:IDN+ch.geni.net+user+nickbas"
  nbastin.addKey("/home/nbastin/.ssh/geni_dsa.pub")

  context = Context()
  context.addUser(nbastin, default = True)
  context.cf = portal
  context.project = "bss-sw-test"

  return context
 }}}

 You will modify this module on from line 7 to line 13, line 16 and line 18 with your own information, and you may want to save it as a different file, for example, with name <your initial>_config.py



 



= Examples of Using geni-lib =
 
 Assuming the module with your credential and project information is named as my_config.py, which is modified from ''example_config.py'' under ./geni-lib/samples, we will illustrate a few examples on how to use geni-lib.

 * Create user context, you will need this for list resources, create slivers, etc. 
{{{
import my_config
context = my_config.buildContext()
}}}
 
 * Get a list of InstaGENI aggregates or ExoGENI aggregates
{{{
import geni.aggregate.instageni as ig
import geni.aggregate.exogeni as eg

def get_am_sites(am_type):
    """
    get a list of sites of a specific aggregate type
    ig: instageni
    eg: exogeni
    """
    am_list = []
    if am_type == 'ig':
        for idx, site in enumerate(ig.aggregates()):
            #print idx, site
            am_list.append(site)
    elif am_type == 'eg':
        for idx, site in enumerate(eg.aggregates()):
            am_list.append(site)
    return am_list
}}}

 * Get Resource information for a specific aggregate (i.e. ig-Clemson), and print it into a file called "ig-clemson-ad.xml"
{{{
import geni.aggregate.instageni as ig

def get_res(context, ig_site=ig.Clemson):
    '''Get resource of a ig site, and print to a file '''
    try:
        ad = ig_site.listresources(context)
        f = open("%s-ad.xml" % (ig_site.name), "w+")
        f.write(ad.text)
        f.close()
        print "[%s] Done" % (ig_site.name)
    except:
        print "[%s] OFFLINE" % (ig_site.name)
}}}



 * Create RSpec Object
{{{
import geni.rspec.pg as pg
rspec = pg.Request()
}}}

 * Create an Xen VM named "node1'"
{{{
vm = pg.XenVM("node1")
}}}

 * Add interface "if0" to ''vm'' ("node1")
{{{
vm_iface = vm.addInterface("if0")
}}}

 * Add custom disk image's URL to the ''vm'' ("node1")
{{{
vm.disk_image = <URL to the custom image>
}}}

 * Add a Service to ''vm'' ("node1"), where service is shell script in a tarball file
{{{
vm.addService(pg.Install(url=<url to the tarball file>, path="/local"))
}}}

 * Add a Execute Service to  ''vm'' ("node1"), where the execute service is a command that is to be run at ''vm''
{{{
vm.addService(pg.Execute(shell="bash", command="/bin/bash /local/<shell script>"))
}}}


 * Add ''vm'' ("node1") to rspec object
{{{
rspec.addResource(vm)
}}}

 * Create a LAN object, and add the interfaces (vm_iface1 and vm2_iface1) associated with this link
{{{
link = pg.LAN('lan0')
link.addInterface(vm_iface1)
link.addInterface(vm2_iface1)
rspec.addResource(link)
}}}

 * Write RSpec File
{{{
rspec.write("test.xml")
}}}

 * Create Slivers, assuming you are using UtahDDC InstaGENI aggregate in the slice "myslice"
{{{
import geni.aggregate.instageni as ig
manifest = ig.UtahDDC.createsliver(context, "myslice", rspec)
}}}


 * Delete Slivers in slice "myslice"
{{{
import geni.aggregate.instageni as ig
ig.Clemson.deletesliver(context, "myslice")
}}}


 * Create EGRE Link Type
{{{
link = pg.L2GRE()
}}}

 * Create Stitched Link Type
{{{
link = pg.StitchedLink()
}}}

 
You can find the complete examples in [http://groups.geni.net/syseng/attachment/wiki/XLiuSandbox/HowToGenerateRSpecUsingGeniLib/helloworld.py here]