[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12

# In case you don't have a valid certitificate this is needed to supress any SSL errors
Add-Type @"
    using System;
    using System.Net;
    using System.Net.Security;
    using System.Security.Cryptography.X509Certificates;
    public class ServerCertificateValidationCallback
    {
        public static void Ignore()
        {
            ServicePointManager.ServerCertificateValidationCallback +=
                delegate
                (
                    Object obj,
                    X509Certificate certificate,
                    X509Chain chain,
                    SslPolicyErrors errors
                )
                {
                    return true;
                };
        }
    }
"@
[ServerCertificateValidationCallback]::Ignore();

Function Get-AuthToken {

    Param($LoadBalancer, $User, $Password)


    #Create the string that is converted to Base64
    $Credentials = $User + ":" + $Password

    #Encode the string to base64
    $EncodedCreds = [System.Convert]::ToBase64String([System.Text.Encoding]::ASCII.GetBytes($Credentials))

    #Add the "Basic prefix"
    $BasicAuthValue = "Basic $EncodedCreds"

    #Prepare the headers
    $Headers = @{
        "Authorization" = $BasicAuthValue
        "Content-Type" = "application/json"
    }

    #Create the body of the post
    $Body = @{"username" = $User; "password" = $Password; "loginProviderName" = "tmos" }

    #Convert the body to Json
    $Body = $Body | ConvertTo-Json

    $Response  = Invoke-WebRequest -Method "POST" -Headers $Headers -Body $Body -Uri "https://$LoadBalancer/mgmt/shared/authn/login"

    #Extract the token from the response
    $Token = ($Response.content | ConvertFrom-Json).Token.token

    Return $Token
}

# Creedentials used to login to the LBs
$User = "admin"
$Password = "admin"
# A list of the load balancers
$Loadbalancers = @("192.168.1.10")

# The user you want to create
$Payload = @{}
$Payload.description = "BigIPReportUser"
$Payload.password = "password"
$Payload.shell = "none"
$Payload.name = "bigipreportuser"
$Payload.role = "guest"
$Payload.partitionaccess = @()
$Payload.partitionaccess += @{ "role" = "guest"; "name" = "all-partitions" }

$JSONPayload = $Payload | ConvertTo-Json -Compress

# For every LB, log in and create the user{}
Foreach($LB in $Loadbalancers){
    $AuthToken = Get-AuthToken -Loadbalancer $LB -User $User -Password $Password
    $Headers = @{}
    $Headers["X-F5-Auth-Token"] = $AuthToken;
    $Headers["Content-Type"] = "application/json"

    $Response = Invoke-WebRequest -Method "POST" -Body $JSONPayload -Headers $Headers -Uri "https://$LB/mgmt/tm/auth/user"
}