Wednesday, August 27, 2008

And here's how to use extended attributes in TADDM

UPDATE: Since TADDM 7.1.2 is MUCH friendlier about extended attributes, I changed the title of this post. Details on reporting on extended attributes to come soon.

... you'll want to be able to populate them during discovery. And this requires the use of the SCRIPT: directive in your custom server template. The documentation on this is pretty sketchy, so that's why I'm including a full script here that will set the value of the "FrankCustom" custom attribute for a LinuxComputerSystem.

Prerequisites
1. You must create the extended attribute named FrankCustom for the LinuxUnitaryComputerSystem class (or any class in its inheritance chain).

2. You must enable the LinuxComputerSystemTemplate custom Computer System sensor. You can do this from the TADDM GUI, Discovery drawer, click on Computer Systems, and edit the LinuxComputerSystemTemplate to set it to "enabled".

3. You have to create a file named $COLLATION_HOME/etc/templates/commands/LinuxComputerSystemTemplate with the following line:

SCRIPT:/myscripts/myscript.py

If it's a Jython script you're calling (which it is in this case), the script filename MUST end with a ".py" extension. If you try to use ".jy", it will absolutely fail.

Now, you need to create the file /myscripts/myscript.py with the following contents:



import sys
import java
from java.lang import System

coll_home = System.getProperty("com.collation.home")
System.setProperty("jython.home",coll_home + "/external/jython-2.1")
System.setProperty("python.home",coll_home + "/external/jython-2.1")

jython_home = System.getProperty("jython.home")
sys.path.append(jython_home + "/Lib")
#sys.path.append(coll_home + "/lib/sensor-extensions")
sys.prefix = jython_home + "/Lib"

import traceback
import string
import re
import StringIO
import jarray

from java.lang import Class
from com.collation.platform.util import ModelFactory
from java.util import Properties
from java.util import HashMap
from java.io import FileInputStream
from java.io import ByteArrayOutputStream
from java.io import ObjectOutputStream


#Get the osobject and the result object
os_handle = targets.get("osobject")
result = targets.get("result")
system = targets.get("system")
# two more pieces of information available
#env = targets.get("environment")
#seed = targets.get("seed")

# Execute a command (it's best to give the full path to the command) and
# store its output in the variable named output
output = os_handle.executeCommand("/bin/ls -l /tmp")
s_output = StringIO.StringIO(output)
output_list = s_output.readlines()

# This loop just stores the last line of output from the above command in
# the variable named "output_line"
for line in output_list:
output_line = line
s_output.close()

#Get the AppServer ModelObject for the MsSql server
#app_server = result.getServer()

#Set up the HashMap for setting the extended attributes
jmap=HashMap()
jmap.put("FrankCustom",output_line)
bos=ByteArrayOutputStream()
oos=ObjectOutputStream(bos)
oos.writeObject(jmap)
oos.flush()
data=bos.toByteArray()
oos.close()
bos.close()

#Call setExtendedAttributes on the AppServer
system.setExtendedAttributes(data)


And there you have it. The examples you find in the documentation and on the TADDM wiki just won't lead you to any kind of success because they're missing some very key information.

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