Load Variables from text file and if key exists in hashtable, use key value - powershell

Question

I'm trying to create a script, where the variables are outside of the PowerShell script. It's just a text file. In that file, we define server name, group names and their values. Group names meaning that the host has these strings in their hostname.
Hostnames have the higher priority, and Group names have the least priority. If neither is present, then there is a default value (inside the ps script).
The following elseif condition isn't working for me and I've tried a lot of other ways but could not get it working.
elseif ($MachineName.Contains("$var.key")) { # Doesn't work. What can be used here?
$foldername = ("$var.value") # Doesn't work. What can be used here?
}
Content of vars.txt:
#Groups
DB=folder7
#Hostnames
server_JIRA_001=folder3
server_DB_001=folder5
server_DB_005=folder6
If a hostname is server_DB_006 it will use value "folder7" as it has the "DB" in their hostname, but if the hostname is server_DB_005 then it will use value "folder6"
Content of script.ps1
$MachineName = "server_DB_006"
$var = (Get-Content "c:\Users\user\Desktop\vars.txt" -Raw | ConvertFrom-StringData)
if ($var.$MachineName -ne $null) {
# if hostname exists, then use its var.value
$foldername = ($var.$MachineName) # returns value of $var.hostname
} elseif ($MachineName.Contains("$var.key")) { # Doesn't work. What can be used here?
# if no hostname defined, then search for group name and use its var.value
$foldername = ("$var.value") # Doesn't work. What can be used here?
} else {
foldername = "default_folder"
}

Answer 1

So you can create a function who will bring back the key name if a string contains it. It loops through the keys and checks the $Text to see if it contains the key text else returns false.
function StringContainsHashTableKey(){
PARAM(
[string]$Text,
[hashtable]$HashTable
)
foreach($i in $Hashtable.Keys.GetEnumerator()){
if($Text -like "*$i*" ){
return $i
}
}
return $false
}
$Var = Get-Content "c:\Users\user\Desktop\vars.txt" -Raw | ConvertFrom-StringData
$MachineName = "server_DB_006"
$KeyMatch = StringContainsHashTableKey -Text $MachineName -HashTable $Var
if ($var.$MachineName -ne $null) { #if hostname exists, then use its var.value
$foldername = ($var.$MachineName) # returns value of $var.hostname
}
# If no hostname defined, then search for group name and use its var.value
Elseif ($KeyMatch -ne $false) { # Doesn't work. What can be used here?
$foldername = $var.$KeyMatch
}
Else {
$foldername = "default_folder"
}
$foldername