# Last Updated: 2022/12/09
# NOTES:
# - You can have this script run locally on the Hyper-V server itself, or you can run it on a monitoring box and pass in an array of Hyper-V host names that it should check.
# - The activity body will contain a bunch of VMs with "Normal" in the Health column if the replication is healthy, so the recommended Success criteria in the
#   CheckCentral check configuration would be (match all):
#     - Body Text - Contains - Normal
#     - Body Text - Doesn't Contain - Warning
#     - Body Text - Doesn't Contain - Critical

###################
# Script Settings #
###################

# Set the allowed TLS versions
$TLSProtocol = [System.Net.SecurityProtocolType] 'Ssl3 , Tls, Tls11, Tls12, Tls13'
[System.Net.ServicePointManager]::SecurityProtocol = $TLSProtocol

# CheckCentral API key
$apiToken = ""

# Set your Hyper-V hosts here
# If running it locally on a single host, you can leave it blank, like this: $hvHosts = @()
$hvHosts = @("hvhost01",
             "hvhost02",
             "hvhost03")

####################################################
# Script Processing (Don't modify below this line) #
####################################################

function createCCActivity ($activitySubject, $activityBody)
{
    Write-Output "`n[INFO] Creating the activity in CheckCentral...`n"
    # Build the activity object
    $ccActivity = [PSCustomObject]@{
        activities = @(
            [PSCustomObject]@{
                subject = $activitySubject
                body = $activityBody
            }
        )
    }

    # Make the API call
    $activityBodyJson = $ccActivity | ConvertTo-Json
    $ccCreateActivitiesRequest = Invoke-WebRequest -Uri "https://api.checkcentral.cc/createActivities/?apiToken=$apiToken" -Method "POST" -ContentType "text/json" -Body $activityBodyJson

    # Confirm that the number of created activities matches the number of activities we sent in
    $ccActivitiesRequestJson = $ccCreateActivitiesRequest.Content | ConvertFrom-Json
    if ($ccActivitiesRequestJson.activities_saved -lt $ccActivitiesRequestJson.activities_received)
    {
        Write-Output "Failed to create $($ccActivitiesRequestJson.activities_received - $ccActivitiesRequestJson.activities_saved) activitie(s) in CheckCentral"
    }
}

# If the $hvHosts array is empty, set it to the hostname of the machine this script is running on
if ($hvHosts.Length -eq 0)
{
    $hvHosts = @("$env:COMPUTERNAME")
}

# Loop through the $hvHosts array to get the replication status for each host and send it to CC
foreach($hvHost in $hvHosts)
{
    # Set the activity subject
    $subject = "Hyper-V Replication Status: $hvHost"

    # Get the replication status from the host
    Write-Output "[INFO] Getting replication status for $hvHost..."
    $replicationStatus = Get-VMReplication -ComputerName $hvHost | Out-String
    if ($replicationStatus -eq "") { $replicationStatus = "No VMs are setup for replication on this server." }

    # Append the hostname of the machine that ran this script to the activity body
    $replicationStatus += "Report generated on $($env:COMPUTERNAME) ($(Get-Date))"

    # Send the activity to CC
    createCCActivity $subject $replicationStatus
}