Add multiple members to powershell hashtable - powershell

Question

I have a CSV file that contains subnet information that I will use to populate a CSV file that has server information in it. I'm starting by importing the subnet information and when processing it, I'm trying to add multiple members to the initial hashtable, but it is not behaving as expected.
The following code processes the first item as expected, creating a new column with the correct information. The code indicates that it processes at least through two more sections, but the members are not added. How do I change the code to allow the creation of multiple members to a single array? The goal is to have each subnet's gateway field (column) be unique to that subnet.
The purpose of the five variables (variableA-E) is to mimic what is occuring in the real code. The real code runs comparisons from the hashtable, but that is not neccessary. I'm willing to change that portion if needed.
CSV file contents:
NetworkName,Subnet,VLANID,Gateway,VLAN
Servers,"192.168.1.0/24","2041","192.168.1.1","ServerVLAN-2041"
Workstations,"192.168.2.0/24","1001","192.168.2.1","WorkstationVLAN-1001"
DMZ,"172.16.0.0/28","340","172.16.0.1","DMZVLAN-340"
Servers,"192.168.3.0/24","2043","192.168.3.1","ServerVLAN-2043"
Workstations,"192.168.4.0/24","1004","192.168.4.1","WorkstationVLAN-1004"
DMZ,,,,
CODE:
$csvfile = "C:\temp\testfile.csv"
$hashArray = Import-CSV $csvfile
$variableA = "192.168.1.0"
$variableB = "192.168.2.0"
$variableC = "192.168.3.0"
$variableD = "172.16.0.1"
$variableE = "192.168.5.0"
$hashArray | % {
if ($_.subnet) { $variable = ($_.subnet).split("/")[0] }
Else { $variable = $null }
if ($variable -eq $variableA -and $variable -ne $null)
{
$_ | add-member "ServerGW1" -NotePropertyValue $_.gateway
Write-Host "Added Server gateway 1: "$_.gateway -ForegroundColor Yellow
}
if ($variable -eq $variableC -and $variable -ne $null)
{
$_ | add-member "ServerGW2" -NotePropertyValue $_.gateway
Write-Host "Added Server gateway 2: "$_.gateway -ForegroundColor Yellow
}
if ($variable -eq $variableB -and $variable -ne $null)
{
$_ | add-member "WorkstationGW1" -NotePropertyValue $_.gateway
Write-Host "Added Workstation gateway 1: "$_.gateway -ForegroundColor Yellow
}
if ($variable -eq $variableD -and $variable -ne $null)
{
$_ | add-member "DMZGW1" -NotePropertyValue $_.gateway
Write-Host "Added DMZ gateway 1: "$_.gateway -ForegroundColor Yellow
}
if ($variable -eq $variableE -and $variable -ne $null)
{
$_ | add-member "WorkstationGW2" -NotePropertyValue $_.gateway
Write-Host "Added Workstation gateway 2: "$_.gateway -ForegroundColor Yellow
}
}
$hashArray | Out-GridView
Out-GridView OUTPUT:
Console OUTPUT:
Expected output:

Answer 1

Out-GridView uses properties from the first object to render columns. All new columns (except ServerGW1) are missing because are not initialized in the first object in your $hashArray. You can initialize with $null value all properties for all rows or provide a list of properties to select before you output your result to Out-GridView
$hashArray | Select-Object NetworkName,Subnet,VLANID,Gateway,VLAN, ServerGW1, ServerGW2,WorkstationGW1,WorkstationGW2,DMZGW1 | Out-GridView
Init all properties:
$hashArray | % {
$variable =if ($_.subnet) { ($_.subnet).split("/")[0] }Else { $null }
$_ | add-member "ServerGW1" -NotePropertyValue $(if ($variable -eq $variableA){ $_.gateway}Else { $null })
$_ | add-member "ServerGW2" -NotePropertyValue $(if ($variable -eq $variableC){ $_.gateway}Else { $null })
$_ | add-member "WorkstationGW1" -NotePropertyValue $(if($variable -eq $variableB){ $_.gateway}Else { $null })
$_ | add-member "DMZGW1" -NotePropertyValue $(if ($variable -eq $variableD ){ $_.gateway}Else { $null })
$_ | add-member "WorkstationGW2" -NotePropertyValue $(if ($variable -eq $variableE){ $_.gateway}Else { $null })
}
$hashArray | Out-GridView

Answer 2

To complement cezarypiatek's helpful answer, which provides the crucial pointer:
All formatting cmdlets, including Out-GridView decide what properties (columns) to show based on the first input object, so to guarantee that the all columns of interest are shown, you must ensure that (at least) the first input object contains all properties of interest.
With that in mind, here's a streamlined version of your approach that does that:
$csvfile = "C:\temp\testfile.csv"
$networks = Import-CSV $csvfile
# Define the subnets and their property names as an ordered hashtable.
$subnets = [ordered] #{
'192.168.1.0' = 'ServerGW1'
'192.168.2.0' = 'ServerGW2'
'192.168.3.0' = 'WorkstationGW1'
'172.16.0.0' = 'DMZGW1'
'192.168.4.0' = 'WorkstationGW2'
}
# Add all properties of interest to the input objects, to ensure
# that Out-GridView (or other formatting cmdlets) show them all.
# Construct an array of property names, where '*' stands for the original properties...
$propNames = #('*') + [string[]] $subnets.Values
# ... and create augmented objects based on them.
$networks = $networks | Select-Object -property $propNames
$networks | % {
# See if the 'subnet' column has a value...
if ($subnet = if ($_.subnet) { ($_.subnet).split("/")[0] } else { $null }) {
# ... and, if so, see if a subnet name is defined for the part before '/' ...
if ($subnets.Contains($subnet)) {
# ... and, if so, fill the subnet-named property with the subnet address.
$_.($subnets.$subnet) = $subnet
}
}
}
Import-CSV doesn't return hashtables it returns custom objects ([pscustomobject] instances).
The code relies on the fact that, in the context of expressions, you can both assign to a variable and use the value of that assignment, such as in a conditional, as is the case here (if ($subnet = ...)).

Answer 3

try this, this example is dynamic, you have just to modify $hashvariable like you want (or load $hashvariable with file if you want)
$csvfile ="C:\temp\testfile.csv"
$hashArray = Import-CSV $csvfile
$hashvariable=[ordered]#{"192.168.1.0"="ServerGW1"; "192.168.2.0"="WorkstationGW1"; "192.168.3.0"="ServerGW2"; "172.16.0.1"="DMZGW1"; "192.168.5.0"="WorkstationGW2" }
$hashArray |
%{
$result=$_
$variable = if ($_.subnet -ne $null) {($_.subnet).split("/")[0]} else {""}
foreach ($key in $hashvariable.Keys)
{
$value=if ($variable -eq $key) {$key} else {""}
$result | add-member $hashvariable[$key] -NotePropertyValue $value
}
}
$hashArray | Out-GridView