vCROCS
About Posts Tags Categories
vCROCS

Contents

PowerShell Script as a Web/API Server

Dale Hassinger included in VCF Automation
   4201 words   20 minutes 
/powershell-script-web-api-server/featured-image.png

How to use PowerShell Scripts as a Web Server or RESTful API Front End Server…

I’m constantly discovering new things, even after years of working with PowerShell. This blog post highlights a feature I only recently came across, and I’m excited to share it with you. My goal is to spark some ideas and inspire new use cases in your own automation journey.

Use Case:

Here’s a PowerShell use case I hadn’t come across until just last week: using a PowerShell script as a web server—no separate web server installation needed. Just run the script, and your machine starts listening for connections on the port you specify. This idea immediately got my wheels turning about all the possibilities this unlocks. You’ll find some example scripts included in this blog.

After getting a basic listener running on port 8080 with a non-SSL connection, I was curious how complex it would be to switch to port 443 with SSL. A bit of research showed it doesn’t take much—just a few changes to the script. Examples of that are also included here.

Once I saw how simple it was to handle incoming web requests, I naturally started thinking: what if a PowerShell script could act as an API front end? I tweaked the listener script to respond to RESTful API requests—and just like that, PowerShell was replying with data to API calls. Not every system you need to pull data from has a REST API, but with this technique, you can make your own. That’s a game-changer for my automation.

PowerShell Script for RESTful API Requests Use Case:

One example is the VCF Operations Management Pack (MP) Builder, which needs to make REST API calls. With this setup, a PowerShell script can serve that role directly. If you can script it, you can expose it as an API and include the data within VCF Operations!

In my automation journey, I’ve yet to find something I couldn’t automate with PowerShell. Adding modules to your scripts unlocks even more use cases—like connecting to remote systems over SSH and parsing the results. Having a PowerShell script act as a RESTful API front end opens up endless possibilities for automation and integration.

Code Examples:

This example is a simple Web Server (non-ssl) that displays text along with the current date and time, which updates on every page load or refresh.

  • Script can be used to show any web page and data you can create. Think about some cool use cases.
  • The image demonstrates how the time updates on each page refresh, highlighting that the web page is dynamic.
/powershell-script-web-api-server/ps-web-api-server-01.gif
Click to see Larger Image

Click arrow to expand the PowerShell code:

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132

# Web Server for Home Lab Use and a Nice way to see how PowerShell can be used.
# Created By: Dale Hassinger

param(
    [int]$port = 8080  # Define a port parameter with a default value of 8080
)

# Flag for cancellation, used to control when to stop the server
$cancelled = $false

# Register an event handler for Ctrl+C (ConsoleBreak)
# When triggered, it sets the $cancelled flag to true so the server can stop gracefully
$null = Register-EngineEvent -SourceIdentifier ConsoleBreak -Action {
    Write-Host "`nCtrl+C detected. Stopping server..."
    $global:cancelled = $true
}

try {
    # Create a new TCP listener that listens on any IP address and the specified port
    $listener = [System.Net.Sockets.TcpListener]::new([System.Net.IPAddress]::Any, $port)

    try {
        # Start the TCP listener
        $listener.Start()
        Write-Host "Server started, listening on port $port..."
    } catch {
        # Handle failure to start the listener
        Write-Host "Failed to start listener: $_"
        return
    }

    # Main loop to keep the server running until cancelled
    while (-not $cancelled) {
        # Check if a client is attempting to connect
        if ($listener.Pending()) {
            # Accept the incoming TCP client connection
            $client = $listener.AcceptTcpClient()
            Write-Host "Client connected: $($client.Client.RemoteEndPoint)"

            # Get the network stream and setup reader/writer for communication
            $stream = $client.GetStream()
            $reader = [System.IO.StreamReader]::new($stream)
            $writer = [System.IO.StreamWriter]::new($stream)
            $writer.AutoFlush = $true  # Ensure output is flushed immediately

            # Read the first line of the HTTP request from the client
            $request = $reader.ReadLine()
            Write-Host "Received: $request"

            # Get the current date and time to include in the HTML response
            $currentDateTime = Get-Date -Format "dddd, MMMM dd, yyyy hh:mm:ss tt"

            # Define the HTML content to return as the response
            $htmlContent = @"
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>PowerShell Web Example</title>
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <style>
        * {
            box-sizing: border-box;
        }
        body {
            margin: 0;
            padding: 0;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            background: linear-gradient(120deg, #f0f2f5, #e2e8f0);
            display: flex;
            justify-content: center;
            align-items: center;
            height: 100vh;
        }
        .container {
            background-color: #ffffff;
            padding: 40px;
            border-radius: 16px;
            box-shadow: 0 10px 30px rgba(0,0,0,0.1);
            max-width: 600px;
            width: 90%;
            text-align: center;
        }
        h1 {
            color: #1a202c;
            font-size: 2rem;
            margin-bottom: 20px;
        }
        .datetime {
            font-size: 1.2rem;
            color: #4a5568;
        }
    </style>
</head>
<body>
    <div class="container">
        <h1>Welcome to a PowerShell Web Site Example</h1>
        <div class="datetime">Current Date and Time: $currentDateTime</div>
    </div>
</body>
</html>
"@

            # Combine HTTP headers and the HTML content into a full HTTP response
            $response = "HTTP/1.1 200 OK`r`nContent-Type: text/html; charset=UTF-8`r`n`r`n$htmlContent"
            Write-Host "Sending response..."

            # Send the response back to the client
            $writer.WriteLine($response)

            # Clean up the network resources
            $reader.Close()
            $writer.Close()
            $client.Close()
            Write-Host "Client disconnected"
        } else {
            # Sleep briefly to reduce CPU usage while waiting for new connections
            Start-Sleep -Milliseconds 100
        }
    }
}
finally {
    # Stop the listener if it exists and isn't already connected
    if ($listener -and $listener.Server.Connected -eq $false) {
        $listener.Stop()
        Write-Host "Server stopped."
    }

    # Clean up the registered Ctrl+C event
    Unregister-Event -SourceIdentifier ConsoleBreak -ErrorAction SilentlyContinue
    Remove-Event -SourceIdentifier ConsoleBreak -ErrorAction SilentlyContinue
}

This example is a simple Web Server (with ssl) that displays text along with the current date and time, which updates on every page load or refresh.

  • Script can be used to show any web page and data you can create. Think about some cool use cases.
  • The image demonstrates how the time updates on each page refresh, highlighting that the web page is dynamic.
/powershell-script-web-api-server/ps-web-api-server-02.gif
Click to see Larger Image

Click arrow to expand the PowerShell code:

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170

# Web Server for Home Lab Use and a Nice way to see how PowerShell can be used.
# Created By: Dale Hassinger

param(
    [int]$port = 443,  # Default port set to 443 for HTTPS
    [string]$certPath = "/Users/dalehassinger/Documents/GitHub/PS-TAM-Lab/vcrocs.pfx",  # Path to the SSL certificate (.pfx)
    [string]$certPassword = "1234"  # Password for the SSL certificate
)

# Attempt to load the SSL certificate from the specified path using the provided password
try {
    $certificate = New-Object System.Security.Cryptography.X509Certificates.X509Certificate2($certPath, $certPassword)
    Write-Host "Certificate loaded successfully."
} catch {
    # If certificate loading fails, write the error and exit
    Write-Host "Failed to load certificate: $_"
    return
}

# Define a cancellation flag to gracefully stop the server when Ctrl+C is pressed
$cancelled = $false

# Register an event to catch Ctrl+C (ConsoleBreak) and flip the cancellation flag
$null = Register-EngineEvent -SourceIdentifier ConsoleBreak -Action {
    Write-Host "`nCtrl+C detected. Stopping server..."
    $global:cancelled = $true
}

try {
    # Initialize a TCP listener on all network interfaces for the specified port
    $listener = [System.Net.Sockets.TcpListener]::new([System.Net.IPAddress]::Any, $port)

    try {
        # Start the TCP listener
        $listener.Start()
        Write-Host "Server started, listening on port $port..."
    } catch {
        # Handle failure to start the listener
        Write-Host "Failed to start listener: $_"
        return
    }

    # Server loop that handles incoming client connections until cancelled
    while (-not $cancelled) {
        if ($listener.Pending()) {
            # Accept an incoming TCP client connection
            $client = $listener.AcceptTcpClient()
            Write-Host "Client connected: $($client.Client.RemoteEndPoint)"

            # Get the underlying network stream from the TCP client
            $networkStream = $client.GetStream()

            # Wrap the network stream in an SslStream to secure communication
            $sslStream = New-Object System.Net.Security.SslStream($networkStream, $false)

            try {
                # Authenticate the server with the loaded certificate, enforcing TLS 1.2
                $sslStream.AuthenticateAsServer($certificate, $false, [System.Security.Authentication.SslProtocols]::Tls12, $false)
                Write-Host "SSL Authentication successful."
            } catch {
                # If TLS handshake fails, close the client connection and continue
                Write-Host "SSL Authentication failed: $_"
                $client.Close()
                continue
            }

            # Create a StreamReader and StreamWriter to handle HTTP data over SSL
            $reader = New-Object System.IO.StreamReader($sslStream)
            $writer = New-Object System.IO.StreamWriter($sslStream)
            $writer.AutoFlush = $true

            try {
                # Attempt to read the first line of the HTTP request
                $request = $reader.ReadLine()
                Write-Host "Received: $request"
            } catch {
                # Handle any errors while reading the request, such as decryption issues
                Write-Host "Error reading request (possible decryption issue): $_"
                $client.Close()
                continue
            }

            # Generate the current date/time to include in the response page
            $currentDateTime = Get-Date -Format "dddd, MMMM dd, yyyy hh:mm:ss tt"

            # Define HTML content to serve in the response, styled with CSS and displaying the current time
            $htmlContent = @"
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>PowerShell Web Example</title>
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <style>
        * {
            box-sizing: border-box;
        }
        body {
            margin: 0;
            padding: 0;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            background: linear-gradient(120deg, #f0f2f5, #e2e8f0);
            display: flex;
            justify-content: center;
            align-items: center;
            height: 100vh;
        }
        .container {
            background-color: #ffffff;
            padding: 40px;
            border-radius: 16px;
            box-shadow: 0 10px 30px rgba(0,0,0,0.1);
            max-width: 600px;
            width: 90%;
            text-align: center;
        }
        h1 {
            color: #1a202c;
            font-size: 2rem;
            margin-bottom: 20px;
        }
        .datetime {
            font-size: 1.2rem;
            color: #4a5568;
        }
    </style>
</head>
<body>
    <div class="container">
        <h1>Welcome to a PowerShell Web Site Example using <span style="color: green;">SSL connection</span></h1>
        <div class="datetime">Current Date and Time: $currentDateTime</div>
    </div>
</body>
</html>
"@

            # Construct a basic HTTP 200 OK response with the HTML content
            $response = "HTTP/1.1 200 OK`r`nContent-Type: text/html; charset=UTF-8`r`n`r`n$htmlContent"
            Write-Host "Sending response..."

            try {
                # Send the response to the client
                $writer.WriteLine($response)
            } catch {
                # Catch any errors during transmission
                Write-Host "Error sending response: $_"
            }

            # Clean up: close the streams and the client connection
            $reader.Close()
            $writer.Close()
            $client.Close()
            Write-Host "Client disconnected"
        } else {
            # Wait briefly before checking for new clients to reduce CPU usage
            Start-Sleep -Milliseconds 100
        }
    }
}
finally {
    # Stop the listener and clean up resources if no active connections remain
    if ($listener -and $listener.Server.Connected -eq $false) {
        $listener.Stop()
        Write-Host "Server stopped."
    }

    # Unregister and remove the Ctrl+C event handler
    Unregister-Event -SourceIdentifier ConsoleBreak -ErrorAction SilentlyContinue
    Remove-Event -SourceIdentifier ConsoleBreak -ErrorAction SilentlyContinue
}

This example is a simple RESTful API front end that returns any data that you have in the PS script.

(4) Sample API calls:

  • Returns Status
  • Returns a simple Hello
  • Returns all the VM Names in my lab vCenter
  • Returns Tiered Memory usage of VMs in my Lab
  • Script can be used to return any data you can create. Think about some cool use cases.
/powershell-script-web-api-server/ps-web-api-server-03.gif
Click to see Larger Image

Click arrow to expand the PowerShell code:

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248

# API Server for Home Lab Use and a Nice way to see how PowerShell can be used.
# Created By: Dale Hassinger

param(
    [int]$port = 8080  # Set the port for the HTTP listener (default 8080)
)

# Ensure required PowerShell modules are installed
$requiredModules = @("powershell-yaml", "VMware.PowerCLI")
foreach ($module in $requiredModules) {
    if (-not (Get-Module -ListAvailable -Name $module)) {
        Write-Host "$module is not installed. Install it using 'Install-Module $module'." -ForegroundColor Red
        exit
    }
}

# Load YAML configuration file (contains vCenter and ESXi credentials)
$cfgFile = "Home-Lab-Config.yaml"
$cfg = Get-Content -Path $cfgFile -Raw | ConvertFrom-Yaml

# Flag for gracefully stopping the API server with Ctrl+C
$cancelled = $false
$null = Register-EngineEvent -SourceIdentifier ConsoleBreak -Action {
    # Log a Ctrl+C (ConsoleBreak) interruption
    New-LogEvent -message "`nCtrl+C detected. Stopping server..." -level "warn"
    $global:cancelled = $true
}

# Function to log messages with timestamp and level coloring
Function New-LogEvent {
    param(
        [string]$message,
        [string]$level
    )
    
    $timeStamp = Get-Date -Format "MM-dd-yyyy HH:mm:ss"

    switch ($level.ToLower()) {
        "info" { Write-Host "[$timeStamp] $message" -ForegroundColor Green }
        "warn" { Write-Host "[$timeStamp] $message" -ForegroundColor Red }
        default { Write-Host "[$timeStamp] $message" -ForegroundColor Yellow }
    }
}

# Main function to process incoming API requests
function Get-ApiResponse {
    param (
        [string]$method,
        [string]$path
    )

    # Split path into route and query string (e.g. /hello?name=Dale)
    $route, $queryString = $path -split '\?', 2
    $params = @{}
    if ($queryString) {
        $pairs = $queryString -split '&'
        foreach ($pair in $pairs) {
            $key, $value = $pair -split '=', 2
            $params[$key] = $value
        }
    }

    # Route handling using switch based on method and path
    switch ("$method $route") {
        "GET /hello" {
            # Return a greeting, optionally personalized with ?name=
            $name = $params["name"]
            if (-not $name) { $name = "vCrocs" }
            return @{
                StatusCode  = "200 OK"
                ContentType = "application/json"
                Body        = "{ `"message`": `"Hello, $name from PowerShell API`" }"
            }
        }
        "GET /status" {
            # Return a simple health check status with timestamp
            return @{
                StatusCode = "200 OK"
                ContentType = "application/json"
                Body = '{ "status": "ok", "time": "' + (Get-Date).ToString("o") + '" }'
            }
        }
        "GET /vms" {
            # Connect to vCenter and retrieve list of VMs (excluding vCLS)
            $vCenter = Connect-VIServer -Server $cfg.vCenter.server -User $cfg.vCenter.username -Password $cfg.vCenter.password -Protocol https
            $vms = Get-VM | Where-Object { $_.Name -notlike "vCLS-*" } | Select-Object Name | Sort-Object Name
            $return = $vms | ConvertTo-Json
            Disconnect-VIServer -Server * -Confirm:$false

            return @{
                StatusCode  = "200 OK"
                ContentType = "application/json"
                Body        = "{""results"":$return}"
            }
        }
        "GET /tiered" {
            # Return detailed memory tier stats (Tier0-RAM and Tier1-NVMe) for each VM
            # Uses sshpass to connect to each host and run esxcli and memstats

            $vCenter = Connect-VIServer -Server $cfg.vCenter.server -User $cfg.vCenter.username -Password $cfg.vCenter.password -Protocol https
            $esxiHosts = Get-VMHost | Select-Object Name | Sort-Object Name
            $combinedResults = @()

            foreach ($esxiHost in $esxiHosts) {
                $server = $esxiHost.Name
                $username = $cfg.Host101.username
                $password = $cfg.Host101.password

                New-LogEvent -message ("Connecting to Host Name: " + $server) -level "info"

                if (-not (Get-Command sshpass -ErrorAction SilentlyContinue)) {
                    Write-Error "sshpass is not installed or not in your PATH. Please install sshpass and try again."
                    exit 1
                }

                # Get VM ID to Name mapping
                $vmCommand = "esxcli --formatter csv vm process list | cut -d ',' -f 2,5"
                $args_vm = @("-p", $password, "ssh", "-o", "ConnectTimeout=10", "-o", "PreferredAuthentications=password", "-o", "PubkeyAuthentication=no", "-o", "StrictHostKeyChecking=no", "$username@$server", $vmCommand)
                $vmOutput = & sshpass @args_vm
                $VMXCartelID = $vmOutput | ConvertFrom-Csv

                # Run memstats to get memory usage details
                $memCommand = 'memstats -r vmtier-stats -u mb -s name:memSize:active:tier0Consumed:tier1Consumed'
                $args_mem = @("-p", $password, "ssh", "-l", $username, $server, $memCommand)
                $memOutput = & sshpass @args_mem

                # Clean and parse memstats output
                $lines = $memOutput -split "`n" | ForEach-Object { $_.Trim() } | Where-Object {
                    $_ -notmatch '^-{2,}|Total|Start|No.|VIRTUAL|Unit|Selected'
                }

                $pattern = '^(?<name>\S+)\s+(?<memSize>\d+)\s+(?<active>\d+)\s+(?<tier0Consumed>\d+)\s+(?<tier1Consumed>\d+)$'
                $tieredMEM = @()

                foreach ($line in $lines) {
                    if ($line -match $pattern) {
                        $tieredMEM += [pscustomobject]@{
                            Name         = $matches['name']
                            MemSizeMB    = [int]$matches['memSize']
                            ActiveMB     = [int]$matches['active']
                            "Tier0-RAM"  = [int]$matches['tier0Consumed']
                            "Tier1-NVMe" = [int]$matches['tier1Consumed']
                        }
                    }
                }

                # Clean up names and match Cartel IDs to Display Names
                $tieredMEM | ForEach-Object { $_.Name = $_.Name -replace '^vm\.', '' }
                $vmNameMap = @{}
                foreach ($entry in $VMXCartelID) { $vmNameMap[$entry.VMXCartelID] = $entry.DisplayName }
                foreach ($vm in $tieredMEM) {
                    if ($vmNameMap.ContainsKey($vm.Name)) { $vm.Name = $vmNameMap[$vm.Name] }
                }

                # Remove system VMs (vCLS)
                $tieredMEM = $tieredMEM | Where-Object { $_.Name -notlike "vCLS-*" }

                # Aggregate host results
                $combinedResults += $tieredMEM
            }

            $return = $combinedResults | ConvertTo-Json
            Disconnect-VIServer -Confirm:$false

            return @{
                StatusCode  = "200 OK"
                ContentType = "application/json"
                Body        = "{""results"":$return}"
            }
        }
        default {
            # Fallback/default response
            return @{
                StatusCode = "200 OK"
                ContentType = "application/json"
                Body = '{ "results": "Default API reply" }'
            }
        }
    }
}

# Start the TCP listener and main server loop
try {
    $listener = [System.Net.Sockets.TcpListener]::new([System.Net.IPAddress]::Any, $port)

    try {
        $listener.Start()
        New-LogEvent -message "API server started on port $port..." -level "info"
    } catch {
        Write-Host "Failed to start listener: $_"
        return
    }

    while (-not $cancelled) {
        if ($listener.Pending()) {
            $client = $listener.AcceptTcpClient()
            $stream = $client.GetStream()
            $reader = [System.IO.StreamReader]::new($stream)
            $writer = [System.IO.StreamWriter]::new($stream)
            $writer.AutoFlush = $true

            $requestLine = $reader.ReadLine()
            New-LogEvent -message "Received: $requestLine" -level "info"

            if ($requestLine -match '^(GET|POST|PUT|DELETE) (/[^ ]*)') {
                $method = $matches[1]
                $path = $matches[2]

                $apiResponse = Get-ApiResponse -method $method -path $path
                $body = $apiResponse.Body

                # Construct HTTP response manually
                $response = @"
HTTP/1.1 $($apiResponse.StatusCode)
Content-Type: $($apiResponse.ContentType)
Content-Length: $($body.Length)

$body
"@

                $writer.Write($response)

                # Log short response preview
                if ($body.Length -ge 50) {
                    $shortBody = $body.Substring(0,50) + "..."
                } else {
                    $shortBody = $body
                }
                New-LogEvent -message "Returned: $shortBody" -level "info"
            }

            # Clean up connection
            $reader.Close()
            $writer.Close()
            $client.Close()
            New-LogEvent -message "Client disconnected"
        } else {
            Start-Sleep -Milliseconds 100
        }
    }
}
finally {
    # Cleanup on exit
    $listener.Stop()
    New-LogEvent -message "Server stopped." -level "warn"
    Unregister-Event -SourceIdentifier ConsoleBreak -ErrorAction SilentlyContinue
    Remove-Event -SourceIdentifier ConsoleBreak -ErrorAction SilentlyContinue
}
  • YAML file contents to use with the PowerShell Script
  • I’ve been using a YAML file with all my current scripts to store values for connecting to vCenter, VCF Operations, VCF Automation, and more. If anything changes, I just update the YAML file, and all the scripts continue to work without any issues.

Click arrow to expand the yaml code:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26

# vCenter Connection
vCenter:
  server: vcsa8x.vcrocs.local
  username: administrator@vcrocs.local
  password: VMware1!
  ignoreCertErrors: true

# A Single ESXi Host Connection
Host101:
  server: 192.168.6.101
  username: root
  password: VMware1!

# VCF Operations
OPS:
  opsURL: https://vao.vcrocs.local
  opsUsername: admin
  opsPassword: VMware1!
  authSource:  local

# VCF Automation
Automation:
  autoURL: vaa.vcrocs.local
  autoUsername: configadmin
  autoPassword: VMware1!
  autoDomain:  System Domain

Here is a sample PowerShell Script web page that is used with the Text Display Widget within a VCF Operations Dashboard.

  • The PowerShell Script is running as a service within a Linux VM
  • There is a 2nd PS script that runs and collects the Tiered Memory Metrics every five minutes and saves the data as a json file that is used with the web page
  • 100s of use cases
/powershell-script-web-api-server/ps-web-api-server-04.gif
Click to see Larger Image

I have been using Rocky Linux more in my lab for testing PowerShell Automation scripts.

Here is how I install PowerShell on Rocky Linux:

Click arrow to expand the cli code:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12


# Install PowerShell
sudo dnf install https://github.com/PowerShell/PowerShell/releases/download/v7.5.0/powershell-7.5.0-1.rh.x86_64.rpm

# Turn off Firewall in your lab to make testing easier
sudo systemctl stop firewalld
sudo systemctl disable firewalld

# Install sshpass to use with PS scripts where you want to make a SSH connection
sudo dnf install epel-release
sudo dnf install sshpass
sshpass -V

How to setup a PowerShell Script to run as a service with Rocky Linux:

Click arrow to expand the cli code:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36


# Create a new service file (e.g., myscript.service) under /etc/systemd/system/:
sudo nano /etc/systemd/system/vcrocs-api.service

# Then add the following content:

[Unit]
Description=PowerShell API Service
After=network.target

[Service]
Type=simple
ExecStart=/usr/bin/pwsh -File /root/http-server-api-test-8080.ps1
Restart=on-failure
RestartSec=10
User=root
WorkingDirectory=/root

[Install]
WantedBy=multi-user.target


# After saving the file, reload systemd to recognize the new service:
sudo systemctl daemon-reload

# Then enable the service so it starts on boot:
sudo systemctl enable vcrocs-api.service

# Start the service
sudo systemctl start vcrocs-api.service

# Service Status
sudo systemctl status vcrocs-api.service

# Stop the Service
sudo systemctl stop vcrocs-api.service

Use Visual Studio Code (VS Code) to create, edit, and run PowerShell scripts on your remote Linux-based PowerShell servers:

  • Try using the VS Code Remote-SSH extension with a Linux server — it’s a setup I really enjoy. Your code is saved and executed directly on the remote Linux machine.
/powershell-script-web-api-server/ps-web-api-server-08.png
Click to see Larger Image

Running a simple PS script on a remote Linux server that uses the VMware PowerCLI module.

/powershell-script-web-api-server/ps-web-api-server-09.gif
Click to see Larger Image

I can edit any type of file I need to on the remote Linux server using this technique

/powershell-script-web-api-server/ps-web-api-server-10.gif
Click to see Larger Image

Steps to create a Self Signed SSL Certifcate to test with:

Click arrow to expand the cli code:

1
2
3
4
5
6
7
8
9

# Using openssl
openssl genrsa -out vcrocs.key 2048

openssl req -new -key vcrocs.key -out vcrocs.csr

openssl x509 -req -days 365 -in vcrocs.csr -signkey vcrocs.key -out vcrocs.crt

openssl pkcs12 -export -out vcrocs.pfx -inkey vcrocs.key -in vcrocs.crt

If you’re primarily a Windows user and hesitant about using Linux, here’s a quick tip: try installing Cockpit — it provides a user-friendly GUI to help manage your Linux VM with ease.

  • Here’s some IT career advice: Get comfortable working with both Windows and Linux. Both operating systems play key roles in enterprise environments.
    • If you’re a Linux user, don’t shy away from using PowerShell. With VMware PowerCLI, automation becomes much easier and more powerful.

Steps to install Cockpit on Rocky Liunux:

Click arrow to expand the cli code:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16


# Update the server
sudo dnf update -y

# install Cockpit
sudo dnf install cockpit -y

sudo systemctl enable --now cockpit.socket

# FW changes
sudo firewall-cmd --permanent --add-service=cockpit
sudo firewall-cmd --reload

# Allow root to use Cockpit
sudo nano /etc/cockpit/disallowed-users
# Remove root

Nice UI for Linux Management:

/powershell-script-web-api-server/ps-web-api-server-05.png
Click to see Larger Image

Watch Performance when the PowerShell scripts are running:

/powershell-script-web-api-server/ps-web-api-server-06.png
Click to see Larger Image

See the PowerShell Services:

/powershell-script-web-api-server/ps-web-api-server-07.png
Click to see Larger Image

Lessons learned:
  • A PowerShell Script can be a Web Server or a RESTful API front end
  • Great way to test web pages in a lab or simple web server
  • The above scripts are cross platform. Can run on Windows, Mac or Linux
  • I like that I can take a bare bones Linux VM, install PowerShell, add the script and I have web pages available or a RESTful API front end
Info
In my blogs, I often emphasize that there are multiple methods to achieve the same objective. This article presents just one of the many ways you can tackle this task. I’ve shared what I believe to be an effective approach for this particular use case, but keep in mind that every organization and environment varies. There’s no definitive right or wrong way to accomplish the tasks discussed in this article.
Lab
Always test new setups and processes, like those discussed in this blog, in a lab environment before implementing them in a production environment.
Tips and Tricks
If you found this blog article helpful and it assisted you, consider buying me a coffee to kickstart my day.
Comments:
Updated on 2025-04-09
 Restful API, Automation, PowerShell, PowerCLI, VMware Code Coach, VMware VExpert, Web Server
Back | Home