How to receive a list of Device Groups

[stephannn]

Hi,
I try to get a list with the device groups I have in Mesh Central. If I understand the https://github.com/Ylianst/MeshCentral/blob/master/meshctrl.js correct I have to use the action meshes. I also get a result back, but I don't see the names of the device groups.

Below is my PowerShell code:

add-type -TypeDefinition @"
using System;
using System.Net;
using System.Net.Security;
using System.Security.Cryptography.X509Certificates;

public static class Dummy {
    public static bool ReturnTrue(object sender,
        X509Certificate certificate,
        X509Chain chain,
        SslPolicyErrors sslPolicyErrors) { return true; }

    public static RemoteCertificateValidationCallback GetDelegate() {
        return new RemoteCertificateValidationCallback(Dummy.ReturnTrue);
    }
}
"@

[System.Net.ServicePointManager]::ServerCertificateValidationCallback = [dummy]::GetDelegate()

$serverUrl = "wss://10.203.145.209:9443/control.ashx"
$username = "administrator"
$password = "administrator"

# Build x-meshauth header
$authHeader = [System.Convert]::ToBase64String([System.Text.Encoding]::UTF8.GetBytes($username)) + "," +
              [System.Convert]::ToBase64String([System.Text.Encoding]::UTF8.GetBytes($password))

# WebSocket client
$ws = [System.Net.WebSockets.ClientWebSocket]::new()
$ct = [System.Threading.CancellationToken]::None

# Add authentication header
$ws.Options.SetRequestHeader("x-meshauth", $authHeader)

$uri = [System.Uri]$serverUrl
$errorVar = $null
try {
    $ws.ConnectAsync($uri, $ct).Wait()
    Write-Host "Connected!"
}
catch {
    Write-Host "Error:" $_.Exception.InnerException.Message
    Write-Host "Details:" $_.Exception.InnerException.ToString()
}

# Build request like the web UI does
$request = @{ action="meshes"; responseid="meshctrl" } | ConvertTo-Json -Compress
$bytes = [System.Text.Encoding]::UTF8.GetBytes($request)
$segment = [System.ArraySegment[byte]]::new($bytes)

# Send
$ws.SendAsync($segment, [System.Net.WebSockets.WebSocketMessageType]::Text, $true, $ct).Wait()

# Receive
$buffer = New-Object byte[] 8192
$segment = [System.ArraySegment[byte]]::new($buffer)
$result = $ws.ReceiveAsync($segment, $ct).Result
$response = [System.Text.Encoding]::UTF8.GetString($buffer, 0, $result.Count)

Write-Host "Response: $response"

Please ignore the password and the certificate settings. This is just a test container.

Any idea what I am doing wrong?
Thanks
Stephan

Edit:
It feels like I am always getting the same result

[si458]

thats because $response is returning the first websocket response then quitting which isnt how websockets work

look at the meshctrl.js for an example - https://github.com/Ylianst/MeshCentral/blob/master/meshctrl.js#L2046-L2612

i copied your code and tested, its returning the serverinfo json then quitting for myself

what you need to do is add code in so that on each response of the websocket you parse the response as json
then check its action and if its the same action as what you asked for
in your case meshes then output the response and quit the powershell

AI EXAMPLE AND FIX:

add-type -TypeDefinition @"
using System;
using System.Net;
using System.Net.Security;
using System.Security.Cryptography.X509Certificates;

public static class Dummy {
    public static bool ReturnTrue(object sender,
        X509Certificate certificate,
        X509Chain chain,
        SslPolicyErrors sslPolicyErrors) { return true; }

    public static RemoteCertificateValidationCallback GetDelegate() {
        return new RemoteCertificateValidationCallback(Dummy.ReturnTrue);
    }
}
"@

[System.Net.ServicePointManager]::ServerCertificateValidationCallback = [dummy]::GetDelegate()

$serverUrl = "wss://meshcentral.mydomain.com/control.ashx"
$username = "USERNAMEHERE"
$password = "PASSWORDHERE"

# Build x-meshauth header
$authHeader = [System.Convert]::ToBase64String([System.Text.Encoding]::UTF8.GetBytes($username)) + "," +
[System.Convert]::ToBase64String([System.Text.Encoding]::UTF8.GetBytes($password))

# WebSocket client
$ws = [System.Net.WebSockets.ClientWebSocket]::new()
$ct = [System.Threading.CancellationToken]::None

# Add authentication header
$ws.Options.SetRequestHeader("x-meshauth", $authHeader)

$uri = [System.Uri]$serverUrl
try {
    $ws.ConnectAsync($uri, $ct).Wait()
    Write-Host "Connected!"
}
catch {
    Write-Host "Error:" $_.Exception.InnerException.Message
    Write-Host "Details:" $_.Exception.InnerException.ToString()
}

# Build request like the web UI does and set action
$action = "meshes"
$request = @{ action = $action; responseid = "meshctrl" } | ConvertTo-Json -Compress
$bytes = [System.Text.Encoding]::UTF8.GetBytes($request)
$segment = [System.ArraySegment[byte]]::new($bytes)

# Send
$ws.SendAsync($segment, [System.Net.WebSockets.WebSocketMessageType]::Text, $true, $ct).Wait()

# Listen for WebSocket data and quit after matching action
while ($ws.State -eq [System.Net.WebSockets.WebSocketState]::Open) {
    $buffer = New-Object byte[] 8192
    $segment = [System.ArraySegment[byte]]::new($buffer)
    $result = $ws.ReceiveAsync($segment, $ct).Result
    if ($result.Count -gt 0) {
        $response = [System.Text.Encoding]::UTF8.GetString($buffer, 0, $result.Count)
        try {
            $json = $response | ConvertFrom-Json
            if ($json.action -eq $action) {
                Write-Host "Response: $response"
                break
            }
        }
        catch {
            Write-Host "Non-JSON response: $response"
        }
    }
    if ($result.EndOfMessage -and $result.MessageType -eq [System.Net.WebSockets.WebSocketMessageType]::Close) {
        break
    }
}

# Close the socket
$ws.CloseAsync([System.Net.WebSockets.WebSocketCloseStatus]::NormalClosure, "Done", $ct).Wait()

[stephannn]

Thanks, this works:

add-type -TypeDefinition @"
using System;
using System.Net;
using System.Net.Security;
using System.Security.Cryptography.X509Certificates;

public static class Dummy {
    public static bool ReturnTrue(object sender,
        X509Certificate certificate,
        X509Chain chain,
        SslPolicyErrors sslPolicyErrors) { return true; }

    public static RemoteCertificateValidationCallback GetDelegate() {
        return new RemoteCertificateValidationCallback(Dummy.ReturnTrue);
    }
}
"@

[System.Net.ServicePointManager]::ServerCertificateValidationCallback = [dummy]::GetDelegate()

$serverUrl = "wss://10.203.145.209:9443/control.ashx"
$username = "administrator"
$password = "administrator"

# Build x-meshauth header
$authHeader = [System.Convert]::ToBase64String([System.Text.Encoding]::UTF8.GetBytes($username)) + "," +
              [System.Convert]::ToBase64String([System.Text.Encoding]::UTF8.GetBytes($password))

# WebSocket client
$ws = [System.Net.WebSockets.ClientWebSocket]::new()
$ct = [System.Threading.CancellationToken]::None

# Add authentication header
$ws.Options.SetRequestHeader("x-meshauth", $authHeader)

$uri = [System.Uri]$serverUrl
$errorVar = $null
try {
    $ws.ConnectAsync($uri, $ct).Wait()
    Write-Host "Connected!"
}
catch {
    Write-Host "Error:" $_.Exception.InnerException.Message
    Write-Host "Details:" $_.Exception.InnerException.ToString()
}

#$ws.Dispose()

# Send your request first
$request = @{ action="meshes"; responseid="meshctrl" } | ConvertTo-Json -Compress
$bytes = [System.Text.Encoding]::UTF8.GetBytes($request)
$segment = [System.ArraySegment[byte]]::new($bytes)
$ws.SendAsync($segment, [System.Net.WebSockets.WebSocketMessageType]::Text, $true, $ct).Wait()

# Buffer for receiving
$buffer = New-Object byte[] 8192

while ($ws.State -eq [System.Net.WebSockets.WebSocketState]::Open) {
    $segment = [System.ArraySegment[byte]]::new($buffer)
    $result = $ws.ReceiveAsync($segment, $ct).Result
    if ($result.MessageType -eq [System.Net.WebSockets.WebSocketMessageType]::Close) { break }

    $response = [System.Text.Encoding]::UTF8.GetString($buffer, 0, $result.Count)
    $json = $null
    try { $json = $response | ConvertFrom-Json } catch {}

    if ($json -eq $null) { continue }

     Write-Host "Action: " $json.action
    switch ($json.action.ToLower()) {
        'serverinfo' {
            Write-Host "Server info received:"
            $json.serverinfo | ConvertTo-Json -Compress | Write-Host
        }
        'meshes' {
            $meshesResult = @()
            foreach ($m in $json.meshes) {
                #$id = ($m._id -split '/')[2]
                $meshesResult += [pscustomobject][ordered]@{ID = ($m._id -split '/')[2]; Name = $($m.name)}
            }
            $ws.CloseAsync([System.Net.WebSockets.WebSocketCloseStatus]::NormalClosure, "", [System.Threading.CancellationToken]::None).Wait()
            break  # exit after processing meshes
        }
        'Close' {
            Write-Host "Close received:"
            [System.Net.WebSockets.WebSocketMessageType]::Close
        }
        default {
            # Uncomment for debugging unknown messages
            # Write-Host "Other message: $response"
        }
    }
   
}

Write-Host $meshesResult

[si458]

brilliant glad you got it sorted! (i gave ai example before not sure if u saw it)

just be aware, its case sensitive, so its not Close but close instead (normally always lowercase)

also im not powershell programmer (im JS hehe) but shouldnt the byte[] be inside the while?
otherwise you will have overflow and more than 8192 bytes could get returned?

also the python library for meshcentral had to remove a websocket byte limit, because 1MB wasnt enough for 1 gent!
HuFlungDu/pylibmeshctrl#48
so 8192 might not be enough bytes for your response! so be aware!