Create a Specific JSON file from csv in PowerShell - json

Question

I have no experience with PowerShell and I was asked to create this script as a favor for a friend of mine. The script is supposed to read a csv file (These files have different columns except for time and host, which are common among all files), and output its content into a JSON file of the following format:
CSV file contains columns:
host| message | time | severity | source |
{
"time": 1437522387,
"host": "dataserver992.example.com",
"event": {
"message": "Something happened",
"severity": "INFO",
"source": "testapp"
#...All columns except for time and host should be under "event"
}
}
*The only guaranteed columns are time and host. All other column headers vary from file to file.
This is part of what I have so far:
$csvFile = Import-Csv $filePath
function jsonConverter($file)
{
#Currently not in use
$eventString = $file| select * -ExcludeProperty time, host
$file | Foreach-Object {
Write-Host '{'
Write-Host '"host":"'$_.host'",'
Write-Host '"time":"'$_.time'",'
Write-Host '"event":{'
#TODO: Put all other columns (key, values) under event - Except for
time and host
Write-Host '}'
}
}
jsonConverter($csvFile)
Any ideas of how I could extract only the remaining columns, row by row, outputting its content to a key, value JSON format like the example above?
Thank you!

Answer 1

Provided your csv looks like this:
"host","message","time","severity","source"
"dataserver992.example.com","Something happened","1437522387","INFO","testapp"
this script:
$filepath = '.\input.csv'
$csvData = Import-Csv $filePath
$NewCsvData = foreach($Row in $csvData){
[PSCustomObject]#{
time = $Row.time
host = $Row.host
event = ($Row| Select-Object -Property * -ExcludeProperty time,host)
}
}
$NewCsvData | ConvertTo-Json
will output this Json:
{
"time": "1437522387",
"host": "dataserver992.example.com",
"event": {
"message": "Something happened",
"severity": "INFO",
"source": "testapp"
}
}

Answer 2

If your powershell version is 3.0 or higher (it should):
Import-CSV $filepath | ConvertTo-JSON
Done!