How do you call Get-F5.iControl multiple times in PowerShell?

Hi wallst

I've fiddled quite a bit with powershell and I must say I've never seen this before. The object is actually not Null, it contains data, but it is not shown for some reason. The only explanation I can think of is that it's a bug.

Check this out:

$user = 'user'
$pass = 'password'

if ( (Get-PSSnapin | Where-Object { $_.Name -eq "iControlSnapIn"}) -eq $null ){
    Add-PSSnapIn iControlSnapIn
}

$success = Initialize-F5.iControl -HostName 10.0.0.1 -Username $user -Password $pass;
$f5 = Get-F5.iControl

Set the partition (good practice)
$f5partitions = $f5.ManagementPartition
$f5partitions.set_active_partition("Common")

 Retrieve a specific iRule DataGroupList
$members = $f5.LocalLBClass.Get_String_Class("images")

 Retrieve a list of all iRules

$irules = $f5.LocalLBRule.query_all_rules()

$members
$irules.Count

For($x=0;$x -lt $IRULES.Count;$x++){
    if($irules[$x].rule_name -eq "/Common/_sys_auth_ssl_crldp") {
        "match"
    }
}

That would give me the following output in my case:

name                                                   members
----                                                   -------
images                                                 {.bmp, .gif, .jpg}
39
match

As you can see the data is there, but not shown. If I post execution enter one of the variables I get the data:

rule_name                                                                                         rule_definition
---------                                           ---------------
/Common/_sys_auth_ssl_cc_ldap                       when CLIENT_ACCEPTED {...
/Common/_sys_auth_ssl_ocsp                          when CLIENT_ACCEPTED {...
/Common/_sys_auth_ssl_crldp                         when CLIENT_ACCEPTED {...
/Common/_sys_auth_krbdelegate                       when HTTP_REQUEST {...
/Common/_sys_https_redirect                         when HTTP_REQUEST {...
...

If I have some more time I'll go through it a bit more, but I hope that helps at least a bit.

Btw, setting the partition is good practice. You can get unpleasant side effects otherwise. 🙂

/Patrik

This worked:

For($x=0;$x -lt $irules.Count;$x++){

    $irules[$x].rule_name
    $irules[$x].rule_definition

}

Also, if you put them in a file you get the data in the variable as well:

$members | Out-File .\test.txt
$irules | Out-File -Append .\test.txt

Very very very annoying. 🙂

/Patrik

Patrick - thanks for taking the time to test and provide feedback. Stating "$NULL" was probably a poor choice on my part as I never tested the condition that $SOMEQUERYRESULT -eq $NULL was $TRUE; but just assumed that was the case because my results were "empty" as you saw. I did out-file the second query and it does contain data. I guess I would need to out-file, and then import that data, for processing; not very pretty...

Hi!

Actually, as the data is there you can go through it and process it.

Try:

For($x=0;$x -lt $irules.Count;$x++){

    $irules[$x].rule_name
    $irules[$x].rule_definition

}

/Patrik

That's a good one. I think it has to do with the default way that objects are pushed to the powershell command pipeline. When the first object is pushed, it sets up a table with columns,etc. When you enter the next object, it's looking for the previous columns (properties) from the last object and when it doesn't find them, it treats it like the object isn't part of the original result set. PowerShell does this so that you can display numerous objects one after another and it will print like they are all part of the same table.

You can get around this by explicitly passing the object through a formatter like format-table or format-list.

For your first example, give this a try:

Code
$IC = Get-F5.iControl
 Retrieve a specific iRule DataGroupList

$MEMBERS = ($IC.LocalLBClass.Get_String_Class("Test_DG")) 
$MEMBERS | Format-Table

 Retrieve a list of all iRules

$IRULES = $IC.LocalLBRule.query_all_rules()
$IRULES | Format-Table

I've been writing PowerShell scripts for almost 10 years and since 99.99% of the time I parse the returned objects, I haven't come across this one. Next time we run into each other, I'll buy you a drink for finding out something I didn't know about PowerShell. If you by chance are at one of our Agility events this year, look me up!

Hope this helps...

-Joe

Hi,

What version of Powershell are you running? I just tested your first 10 lines and both iRules and "Test_DG" are returned. I am running Powershell version 5 and iC version 11.3.0, but it may be fixed in a later version of Powershell than what you are running.

-Dean