Fabric Basics

Overview

Constructing a Fabric object in Python is VERY easy. You simply need to know the ip address of ANY Node in your configuration ... Thats it. The API will do the rest!

What purpose do Fabric objects in Python do for me as a user?

At a glance, they’re useful for:

• Performing the same action on one, all, or a subset of nodes.
• Gathering real time information from the Fabric (statistics, topology, software versions, etc.)

Note

• This tutorial assumes:

  • Basic Object Oriented Programming knowledge
  • Basic Python language syntax and data structures

Example

Lets start by stating what the end goals of this example will be:

1. Construct a Fabric object using the Cxmanage API.
2. Query the Fabric object for version information from each node.
3. Print out the information.

Now lets dive right in with code ...

You can either write a script in your favorite text editor of choice or use Python’s Interactive Interpreter. The interactive interpreter is used for these code examples, however ANY of this code can be copied/pasted into a script.

To start the Interactive Interpreter, at a terminal command-line prompt:

python
 Python 2.7.3 (default, Aug  1 2012, 05:14:39)
 [GCC 4.6.3] on linux2
 Type "help", "copyright", "credits" or "license" for more information.
>>>

Note

• If you’re using a Virtual Environment ... BEFORE you start the interpreter, be sure to:

  workon <VirtualEnvironment Name>

See also

Using the Python Interpreter

The Code

from cxmanage_api.fabric import Fabric
my_fabric = Fabric('10.20.1.9')               # 1. Construct a Fabric Object ...
versions = my_fabric.get_versions_dict()      # 2. Get the versions info for each node ...

for node_number, version in versions.items(): # 3. Print out the Information
    print 'SW/HW Version Info for Node %d:\n' % node_number
    for key, value in version.items():
        print('%s = %s' % (key, value))
print('=' * 80)

Thats it! In less than 10 lines of code, we accomplished all of our stated goals with the help of the Cxmanage API. Additionally, this code scales for Fabrics of N nodes.

The Output

SW/HW Version Info for Node 0:

iana = 38605
ubootenv_version = v2013.01-rc1_cx_2013.01.17-2-g3e
ecme_version = v1.1.0-141-g8091aea
hardware_version = EnergyCard X02
cdb_version = v1.1.0-141-g8091aea
ecme_timestamp = 1362686083
bootlog_version = v1.1.0-141-g8091aea
a9boot_version = v2012.12.21-5-gf0559d7
stage2_version = v1.1.0-141-g8091aea
dtb_version = v3.8-rc4-2-gc841f01
firmware_version = ECX-1000-v2.1.1-1-g56b6358
uboot_version = v2013.01-rc1_cx_2013.01.17-2-g3e
================================================================================
SW/HW Version Info for Node 1:

iana = 38605
ubootenv_version = v2013.01-rc1_cx_2013.01.17-2-g3e
ecme_version = v1.1.0-141-g8091aea
hardware_version = EnergyCard X02
cdb_version = v1.1.0-141-g8091aea
ecme_timestamp = 1362686083
bootlog_version = v1.1.0-141-g8091aea
a9boot_version = v2012.12.21-5-gf0559d7
stage2_version = v1.1.0-141-g8091aea
dtb_version = v3.8-rc4-2-gc841f01
firmware_version = ECX-1000-v2.1.1-1-g56b6358
uboot_version = v2013.01-rc1_cx_2013.01.17-2-g3e
================================================================================
SW/HW Version Info for Node 2:

iana = 38605
ubootenv_version = v2013.01-rc1_cx_2013.01.17-2-g3e
ecme_version = v1.1.0-141-g8091aea
hardware_version = EnergyCard X02
cdb_version = v1.1.0-141-g8091aea
ecme_timestamp = 1362686083
bootlog_version = v1.1.0-141-g8091aea
a9boot_version = v2012.12.21-5-gf0559d7
stage2_version = v1.1.0-141-g8091aea
dtb_version = v3.8-rc4-2-gc841f01
firmware_version = ECX-1000-v2.1.1-1-g56b6358
uboot_version = v2013.01-rc1_cx_2013.01.17-2-g3e
================================================================================
SW/HW Version Info for Node 3:

iana = 38605
ubootenv_version = v2013.01-rc1_cx_2013.01.17-2-g3e
ecme_version = v1.1.0-141-g8091aea
hardware_version = EnergyCard X02
cdb_version = v1.1.0-141-g8091aea
ecme_timestamp = 1362686083
bootlog_version = v1.1.0-141-g8091aea
a9boot_version = v2012.12.21-5-gf0559d7
stage2_version = v1.1.0-141-g8091aea
dtb_version = v3.8-rc4-2-gc841f01
firmware_version = ECX-1000-v2.1.1-1-g56b6358
uboot_version = v2013.01-rc1_cx_2013.01.17-2-g3e
================================================================================

Line by Line Explaination

Line 1: Imports the Fabric class from the installed cxmanage_api.

from cxmanage_api.fabric import Fabric

Line 2: Accomplished our first goal by creating the Fabric object with an ip address we knew about.

my_fabric = Fabric('10.20.1.9')

Line 3: Accomplished our second goal by simply asking the Fabric for Node version info and storing the result in the ‘versions’ variable, which is a dictionary in the format: {node_number : {version: info}}.

versions = my_fabric.get_versions_dict()

Line 4: Is blank ... it does nothing but serves the purpose of nice code format.

Line 5: Is a for loop that is going to iterate over the versions dictionary of result objects and store the keys to the dictionary in variable: node_number, as well as store the values for each key in the variable version.

for node_number, version in versions.items():

Line 6: The first of a couple of print statements (Goal #3). Its going to print some text but most notably, its going to do this on every iteration of the for loop and filling in node_number for every %d. The \n is just a new-line character.

print 'SW/HW Version Info for Node %d:\n' % node_number

Line 7: Starts another for loop that will get each version attribute, and its value and assign them to the variables ‘key’ and ‘value’. We do this so we can print out each different HW/SW version.

for key, value in version.items():

Line 8: Prints the key and its value for the version.

print('%s = %s' % (key, value))

Line 9: Prints the character ‘=’ 80 times.

print('=' * 80)