Category Archives: Tutorials and guides

Logic, Software, Tutorials and guides

Scrum story points: how a Jedi mind trick saved my sprints

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Remember the days when people were proclaiming that Scrum can cure cancer? Not as a joke but, like, seriously? Ah, those were the days šŸ¤¦ā€ā™‚ļø

Of course, that was all a bunch of… trying to sound professional here… nonsense. Yes, it helps if teams of all disciplines can organize their work efficiently. But, I’m sure you’ll be surprised to hear, their work organization before scrum wasn’t exactly a pile of papers thrown around randomly.

After the initial years of agile and scrum hype, the inevitable realization kicked in. That’s not to say scrum isn’t a useful way of organizing work; it definitely is. But parts of it were brought to reality. And a big one was story points.

Using fibonacci numbers to estimate story points
A terrible AI-generated image of hands, with varying number of fingers, holding cards with Fibonacci numbers. Yes, the “8” looks more like a Greek beta “Ī²”.

People came to hate them so very, very much. You can read headlines like “Story Points Are Dead“, “5 Reasons Why Your Story Points Arenā€™t Working” and so on.

And for good reason. People feel so strongly against them because they are hard to estimate. I’ve been in exhausting hours-and-hours-long meetings trying to get them right. Plus, do they really work? If youā€™ve spent more than fifteen minutes in a Scrum environment, youā€™ve heard the “Classical Scrum” lecture: ā€œStory points measure complexity, not time!ā€ Itā€™s a beautiful, noble sentiment. Itā€™s also, quite frankly, a load of… trying to sound professional here… nonsense.

The Great Divide


On one side, you have the Dev team, trying to explain that a “3” is like a medium-sized cat: “itā€™s not about how long it takes to wash the cat, itā€™s about how many claws the cat has“.

On the other side, you have literally everyone elseā€”Stakeholders, Project Managers, and probably their puppiesā€”who only want to know one thing: ā€œWhen is this going to be finished?ā€

You can explain Fibonacci sequences until youā€™re blue in the face, but the business runs on calendars, not abstract integers. We techies need to answer the “when” question without losing our souls -or our weekends.

So, I stopped fighting human nature. Instead, I started using a mind trick.

The Trick: “Days” That Arenā€™t Days (But are) (Well, kind of) (But not really) (Eh, sort of)

Here is the system I use to bridge the gap between devs and, for a lack of better term, the real world.

I tell my team we are estimating effort in sizes: Small, Medium, and Large. Butā€”and hereā€™s the trickā€”I tell them to estimate those sizes using “Days of Effort.”

These are not the story points you’re looking for

For a 3-week sprint (15 working days), I only allow three choices:

  • Small: 2 “Days”
  • Medium: 5 “Days”
  • Large: 15 “Days”

Wait, a 15-day story in a 15-day sprint? Yes. Because we all know that “Large” actually means “This is the only thing I am doing, and Iā€™ll probably still be screaming at my IDE on Friday afternoon.”

The “Phase 2” Maneuver (Handling the Unfinished)

Sprints are messy. When the clock runs out, i.e. on the last day of the sprint, and items aren’t done, we donā€™t just “carry them over” and pretend nothing happened. We follow two rules:

  • The “Zero Progress” Rule: If no work was done during the sprint, the item moves to the next sprint as-is.
  • The “Downgrade” Rule: If some work was done, we downgrade the effort by one grade (15 becomes 5, 5 becomes 2, 2 stays 2) and set it to “Done”. We then create a “Phase 2” copy of the ticket for the next sprint with the effort that we estimate is remaining -can be anything from Small to Large. If the item (usually a PBI) has unfinished tasks, we change their parent to the new PBI and move them to the next sprint as well.

Note: we only estimate PBIs, not Tasks. In our board, Tasks are welcome and encouraged, but not mandatory.

At the end of the sprint, we look at what was actually finished. We take the average of the last three sprints, and that is our Velocity. If our average is 90 “effort-days”, we donā€™t commit to 150. We arenā€™t heroes; weā€™re mathematicians (well, the good kind).

Why Does This Work? (The Science of Being Wrong)

To be clear, Iā€™m not lying to anyone. I tell my team, the stakeholders, and their puppies (yes I actually tried once; the puppy seemed to nod in agreement though she may have thought I’ll give her a treat and was promptly disappointed) exactly how this works. And yet, it still works. Why?

No idea, I just want my treat

Because developers are notoriously terrible at estimation, butā€”and this is keyā€”we are consistently terrible.

Think of it as the Mindset Coefficient Ī¼.

When a developer estimates the effort E required to complete a piece of work, the real effort R can be calculated by:

R=Ī¼Ć—ER = Ī¼ Ɨ E

The value of Ī¼ depends on the specific people in the room. As long as the team remains the same, Ī¼ stays remarkably constant. They might think theyā€™re estimating “days,” but theyā€™re actually providing a consistent unit of “their own personal version of time.”

No, not this version of time

By using the downgraded “Phase 2” tickets and the 3-sprint average, we are effectively solving for Ī¼ using real-world data. We aren’t trying to force developers to be “correct”; we are calibrating our planning to account for their specific brand of optimism. The famous developer’s optimism is the reason why Ī¼ is always always always >1.

An Example

Let’s say we start the sprint with 4 PBIs:

  • PBI S1 and S2 are estimated at 2 “days”.
  • PBI L3 is estimated at 15 “days”.
  • PBI M4 is estimated at 5 “days”.
  • In the middle of the sprint, as it often happens, there’s an urgent issue. So we add a PBI M5 which we estimate at 5 “days”.

At the end of the sprint, we’ve finished S1, M4 and M5. So we set them to done (obviously this can be done earlier, doesn’t have to be on the last day).

For S2, we set it to Done. It’s at 2 “days” so this stays the same. We then create a copy “S2 – Phase 2” which we estimate at 2 “days” for the remaining work and assign it to the next sprint.

For L3, we set it to Done. It’s at 15 “days” so we change it to 5 (downgrade by one grade, remember?). Note that the change, in Azure Devops at least, has to be made before setting it to Done. We then create a copy “L3 – Phase 2” which we estimate at 5 “days” for the remaining work and assign it to the next sprint.

So what’s our velocity? For this sprint it’s:

  • Finished S1, M4 and M5 = 2 + 5 + 5 = 12 “days”.
  • Unfinished S2 and L3 = 2 + 5 = 7 “days”.
  • Total 19 “days” of effort.

Of course that’s for a single sprint; we need to average over the last 3, but even if it’s the first sprint of the team, it’s still a useful indicator.

The Result

The team stops sweating the “Complexity vs. Time” debate. Estimation becomes an easy exercise because the options are both relatable and limited. The business gets a velocity they can actually use to project a release date.

Itā€™s a Jedi mind trick because even though everyone knows the “days” aren’t literal, their brains start treating them that way. They think in days, we plan in days, and the “Mindset Coefficient” handles the translation to reality.

Want more “honestly-it-works” advice? Check out my previous post on How to store secrets the right way. Because your API keys shouldn’t be as public as your estimation errors šŸ˜Š

Databases, Software, Tutorials and guides

C#: If your Data Access Layer leaks, you’re gonna get wet (here’s how to do it right)

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So the other day Iā€™m doing a code review in an enterprise application. The goal was to switch the data storage from SharePoint Online Lists to Azure SQL database tables. “Easy,” I thought. “It’s just a change in the Data Access Layer (DAL)”.

Long story short, I started reviewing the source code and… wasn’t amused. This was (a small sample of) the problem:

AdminService.cs
C#
public class AdminService
{
	public AdminService(ILogger<AdminService> logger, ISharePointService sharePointService, IConfiguration configuration)
	{
		// initialization code
	}
	
	public async Task<Metadata> AddEmployeeDirectoryItem(PnPContext adminContext, PersonCreated personCreated)
	{
	   // Add Employee Directory stuff
	}
	// etc etc
}

I mean, dear programmer, look. You want to add a directory related to an employee. I get it. But why is the PnPContext sitting there in the method signature like an uninvited guest at a wedding?

This is what we call a “Leaky Abstraction.” Your Data Access Layer (DAL) is leaking its internal stuff all over your business logic. Depending on the case, today itā€™s Sharepoint, tomorrow itā€™s SQL Server, and the day after itā€™s a carrier pigeon. If your business logic knows in what kind of medium your data is stored in, you’re in for a world of hurt.

The Problem: When your DAL tells too much

The core issue is coupling. When you pass an SqlConnection, an SqlDataReader, or a SharePoint PnPContext directly into your business services, you are essentially tattooing your data vendor onto your forehead.

If you leak these details:

  1. You can’t switch providers: Moving from SQL to SharePoint to Oracle to clay tablets becomes a “rewrite everything” project instead of a “change one class” task.
  2. Testing is a nightmare: You can’t unit test your business logic without a Sharepoint, SQL Server etc. running, because your methods demand a real connection.
  3. Code smell: Your business logic should care about what is being saved, not how the connection string is formatted.

The “Wrong” Way: The Leaky Bucket

Take a look at this example. Itā€™s the kind of code that works fine during development, works fine in UAT, but makes you want to retire when requirements change.

InvoiceLogic.cs
C#
// Somewhere in the Business Logic Layer
public void ProcessInvoice(int invoiceId, string connectionString)
{
    using (SqlConnection conn = new SqlConnection(connectionString))
    {
        conn.Open();
        // Why is my Business Logic managing SQL connections?!
        var cmd = new SqlCommand("SELECT * FROM Invoices WHERE Id = @id", conn);
        cmd.Parameters.AddWithValue("@id", invoiceId);
        
        // ... process logic ...
    }
}

Did you notice? The business logic is doing the heavy lifting of database management. If the boss says “We’re moving to an OData API,” you have to touch every single file in your project.

Ugh I can’t even

The Solution: The Repository Pattern

So how do you do this correctly?

First of all, itā€™s a good idea not to reinvent the wheel. You can use the Repository Pattern. Think of a Repository as a mediator between the domain and the data mapping layers. It acts like an in-memory collection of domain objects.

Your business logic should talk to an Interface, and that interface should speak the language of your business (Invoices, Customers, Files), not the language of your storage (Tables, Blobs, Transactions).

The Refactored Way: Clean and Dry

Letā€™s fix that mess. First, we define what we want to do, without mentioning the data storage medium. Here’s an example of an invoice processor:

1. Clean business objects

Invoice.cs
C#
public class Invoice
{
    public int Id { get; set; }
    public string CustomerName { get; set; }
    public decimal Amount { get; set; }
    public DateTime IssueDate { get; set; }
    public List<InvoiceItem> Items { get; set; } = new List<InvoiceItem>();
    // You can add business logic here...
    public void ApplyDiscount(decimal percentage)
    {
        Amount -= Amount * (percentage / 100);
    }
    
    // ...but NEVER data access logic!
}
public class InvoiceItem
{
    public string Description { get; set; }
    public decimal Price { get; set; }
}

2. Repository Interface

IInvoiceRepository.cs
C#
public interface IInvoiceRepository
{
    Invoice GetById(int id);
    void Save(Invoice invoice);
}

Notice how the interface uses only basic types (such as int, string etc) or our clean business objects. It should NEVER use data store-specific types, such as DataRow.

3. The Business Logic (the right way)

Now, the business logic is blissfully ignorant. Itā€™s like a person ordering a pizza who doesn’t care if the oven is electric or wood-fired.

InvoiceService.cs
C#
public class InvoiceService
{
    private readonly IInvoiceRepository _repo;
    public InvoiceService(IInvoiceRepository repo) 
    {
        _repo = repo; // Dependency Injection!
    }
    public void ProcessInvoice(int invoiceId)
    {
        var invoice = _repo.GetById(invoiceId);
        // Do actual business work here...
        _repo.Save(invoice);
    }
}

3. Data layer implementation

Now, you can have a SqlInvoiceRepository for today, and a SharePointInvoiceRepository for tomorrow. The rest of your app won’t even notice the difference. All they need is to implement IInvoiceRepository.

Final Thoughts

It’s tempting to just “pass the connection” because it’s faster. It’s easy to forget that code lives longer than infrastructure.

But in any case, be careful to consider your future self (not to mention others that might maintain your code). Is your software supposed to grow? A good place to start is decoupling.

Whatever you do, PLEASE PLEASE PLEASE DON’T LEAK YOUR DAL DETAILS.

…or you’ll end up like these poor people
Software, Tutorials and guides

Stop CI/CD pipeline if a Powershell script contains errors

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Contrary to “normal” languages like C# or Java, Powershell is not a compiled language, but rather an interpreted one. This means that instead of using a compiler, the Powershell Scripting Runtime Environment reads and executes the code line-by-line during runtime.

That has well known advantages -for example, you can change code on the spot- and disadvantages -e.g. performance. But one major disadvantage is that there are no compiler errors. That means that if you forget to close a parenthesis or a bracket, nothing works. It’s the silliest of mistakes but still crashes everything.

With Powershell being used in non-interactive environments, like Azure Functions, it’s becoming all the more important to guard against such errors.

Fortunately, there is a solution for this. Microsoft has published the PSScriptAnalyzer module (link) which includes the Invoke-ScriptAnalyzer (link) command. Running this against your code, you get a list of warnings and errors:

The best things is, you can include this in your CI/CD pipelines, e.g. in Azure Devops or Github.

So here’s an example of an Azure Devops pipeline task that checks for ParseErrors (meaning, the script is not readable) and stops the build in case such an error is found:

#
# Source: DotJim blog (http://dandraka.com)
# Jim Andrakakis, October 2024
#
- task: PowerShell@2
  displayName: Check for Powershell parsing errors
  inputs:
    targetType: 'inline'
    errorActionPreference: 'stop'
    pwsh: true
    script: | 
      Install-Module -Name PSScriptAnalyzer -Scope CurrentUser -Force
      Write-Host 'Performing code analysis using Microsoft Invoke-ScriptAnalyzer'
      $findings = Invoke-ScriptAnalyzer -Path '$(System.DefaultWorkingDirectory)' -Recurse -Severity ParseError,Error
      $findings | Format-List
      if (($findings | Where-Object { $_.Severity -eq 'ParseError' }).Count -gt 0) { Write-Warning "Parse error(s) were found, review analyser results."; exit 1 }

Enjoy šŸ˜Š

Software, Tutorials and guides

How to get a backup of your Azure Devops repository including all branches

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While Azure Devops is widely used, Microsoft’s backup solutions are surprisingly thin. With people depending on it, individuals and enterprises alike, you’d expect a bit more.

There are various tools around, but here’s my version in the form of a Powershell script. What it does is:

  • Connects to a specific Azure Devops project and repo.
  • Lists all branches, downloads them using git and zips them.
  • The zip, one for every branch, is named Backup_yyyy-MM-dd_branch.zip.

Prerequisites are not much, but:

  • You need git installed and
  • you need a PAT with read access to your code (instructions here).

So here’s the script:

#
# Source: DotJim blog (https://dandraka.com)
# Jim Andrakakis, October 2024
# Updated September 2025, fix for projects and orgs containing spaces
#

# BackupBranches.ps1

param (
    [string]$organization = "MYORG",
    [string]$project = "MYPROJECT",
    [string]$repository = "MYREPO",
    [string]$backupFolder = "C:\Temp\DevOpsBranches",    
	[string]$branchFilter = "" # leave empty for all branches
)

Clear-Host
$ErrorActionPreference='Stop'
 
$pat = Read-Host -MaskInput -Prompt "Enter Personal Access Token for $($env:USERNAME) and $($project)/$($repository)"
$base64AuthInfo = [Convert]::ToBase64String([Text.Encoding]::ASCII.GetBytes(":$pat"))
 
$tempFolder = Join-Path $backupFolder $repository
$repoNoSpace = $repository.Replace(' ','%20')
$projNoSpace = $project.Replace(' ','%20')
 
Write-Host "[$([datetime]::Now.ToString('yyyy-MM-dd HH:mm:ss'))] Starting, output directory is $tempFolder"
 
# Ensure temp folder exists
if (-not (Test-Path -Path $tempFolder)) {
    New-Item -Path $tempFolder -ItemType Directory | Out-Null
}
 
# API URL for branches
$branchesApiUrl = "https://dev.azure.com/$organization/$projNoSpace/_apis/git/repositories/$repoNoSpace/refs?filter=heads/&api-version=6.0"
 
# Get all branches from the repository
$response = Invoke-RestMethod -Uri $branchesApiUrl -Headers @{Authorization=("Basic {0}" -f $base64AuthInfo)}
 
$branchList = $response.value | Sort-Object -Property name
 
# Iterate through each branch
foreach ($branch in $branchList) {
	try {
		$branchName = $branch.name -replace "refs/heads/", ""

		# branch filter, if any
		if (-not ([string]::IsNullOrWhiteSpace($branchFilter)) -and ($branchName -notlike "*$branchFilter*")) {
			continue
		}
	 
		# Define the folder for the branch
		$branchNameStrilized = "$($branchName.Replace('/','_').Replace(' ','_'))"
		$branchFolder = "$tempFolder\$branchNameStrilized"
		 
		# Remove the folder if it exists from previous runs
		if (Test-Path -Path $branchFolder) {
			Remove-Item -Recurse -Force $branchFolder
		}
	 
		# Clone the specific branch
		$gitUrl = "https://dev.azure.com/$organization/$projNoSpace/_git/$repoNoSpace"
		Write-Host "Cloning branch '$branchName' from $gitUrl to $branchFolder"
		$gitResp = [string] (& git clone --branch $branchName --single-branch $gitUrl $branchFolder 2>&1)
		if ($gitResp -like "*fatal*") {
			Write-Error "Error cloning branch '$branchName': $gitResp"
		}
	 
		# Zip the branch folder
		$backupDate = [datetime]::Now.ToString('yyyy-MM-dd')
		$zipFilePath = "$tempFolder\Backup_$($backupDate)_$($branchNameStrilized).zip"
		if (Test-Path $zipFilePath) {
			Remove-Item $zipFilePath
		}
		Compress-Archive -CompressionLevel Fastest -Path "$branchFolder\*" -DestinationPath $zipFilePath
	 
		Write-Host "Branch '$branchName' zipped to $zipFilePath"
	 
		# Clean up branch folder after zipping
		Remove-Item -Recurse -Force $branchFolder
	}
	catch {
		Write-Warning $_
	}
}
 
Write-Host "[$([datetime]::Now.ToString('yyyy-MM-dd HH:mm:ss'))] Finished, $($response.value.Count) branches processed."

Usage example:

BackupBranches.ps1 -organization 'BIGBANK' -project 'KYCAML' -repository 'KYCAMLapiV2' -backupFolder '\\backupfileserver\codebackups\'
Cryptography, Security, Software, Tutorials and guides

Powershell: How to store secrets the right way

1 Comment

There are secrets that can be deadly.

Here we’re not going to talk about this kind šŸ˜Š But that doesn’t mean it’s not important.

It happens quite often that a script you need to run needs access to a resource, and for this you need to provide a secret. It might be a password, a token, whatever.

The easy way is obviously to have them in the script as variables. Is that a good solution?

If you did not answer NO THAT’S HORRIBLE… please change your answer until you do.

Ok so you don’t want to leave it lying around in a script. You can ask at runtime, like this:

$token = Read-Host -Prompt "Please enter the connection token:" -AsSecureString

That’s definitely not as bad. But the follow up problem is, the user needs to type (or, most probably, copy-paste) the secret every time they run the script. Where do the users store their secrets? Are you nudging them to store it in a notepad file for convenience?

In order to keep our systems safe, we need a way that is both secure and convenient.

That’s why using the Windows Credential Manager is a much, much better way. The users only have to recover the secret once, and then they have it stored in a safe way.

Here’s an example of how you can save the secret in Windows Credential manager. It uses the CredentialManager module.

# === DO NOT SAVE THIS SCRIPT ===

# How to save a secret

# PREREQUISITE: 
# Install-Module CredentialManager -Scope CurrentUser

$secretName = 'myAzureServiceBusToken' # or whatever

New-StoredCredential -Target $secretName -Username 'myusername' -Pass 'mysecret' -Persist LocalMachine

And here’s how you can recover and use it:

# How to use the secret

# PREREQUISITE: 
# Install-Module CredentialManager -Scope CurrentUser

$secretName = 'myAzureServiceBusToken' # or whatever

$cred=Get-StoredCredential -Target $secretName
$userName = $cred.UserName
$secret = $cred.GetNetworkCredential().Password

# do whatever you need with the secret

Just for completeness, here’s an example of how to call a REST API with this secret. I imagine that’s one of the most common use cases.

#
# Source: DotJim blog (https://dandraka.com)
# Jim Andrakakis, April 2024
#

# PREREQUISITES: 
# 1. Install-Module CredentialManager -Scope CurrentUser
# 2. New-StoredCredential -Target 'myRESTAPICredential' -Username 'myusername' -Pass 'mysecret' -Persist LocalMachine

# === Constants ===
$uri = 'https://myhost/myapi'
$credName = 'myRESTAPICredential'
$fileName = 'C:\somepath\data.json'
# === Constants ===

$cred=Get-StoredCredential -Target $credName
$pair="$($cred.UserName):$($cred.GetNetworkCredential().Password)"
$encodedCreds = [System.Convert]::ToBase64String([System.Text.Encoding]::ASCII.GetBytes($pair))
$basicAuthValue = "Basic $encodedCreds"

$headers = @{
    Authorization = $basicAuthValue;
    ContentType = 'application/json';
    Accept = 'application/json'
}

try {
    $resp = Invoke-WebRequest -UseBasicParsing -Uri $uri -Headers $headers -Method Post -InFile $fileName
}
catch {
    $errorMsg = "Error sending file '$fileName', exception in line $($_.InvocationInfo.ScriptLineNumber): $_.Exception.Message $_"
    Write-Warning $errorMsg     
}
Software, Tutorials and guides

Powershell: Get Active Directory group members (without the need to install the ActiveDirectory module)

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Powershell offers a number of Active Directory (AD for short) commandlets to make an AD admin’s life a little easier. For example, if you need to get a list of members from an AD group, you can use something like:

Get-ADGroupMember_example.ps1
PowerShell
Get-ADGroupMember -Identity 'Enterprise Admins' -Recursive

The problem is that this doesn’t work everywhere. The ActiveDirectory module is not a “normal” one you can install with Install-Module; instead, you need to install a Windows feature, either from Control Panel or by using the Add-WindowsCapability commandlet.

But you don’t have to use this module. You can use something that’s available everywhere, the adsiSearcher type accelerator.

So here are a couple of scripts I came up with (credits where they’re due). The first searches through all groups, finds all the ones that match a string and lists all their members.

Get-AdsiSearcherGroups.ps1
PowerShell
#
# Source: DotJim blog (https://dandraka.com)
# Jim Andrakakis, January 2024
# Updated April 2026 to add regex
# Thanks to Diego for the inspiration!
#
  
# ===== Parameters =====
  
param(
    # use either a substring or a regex
    # e.g. AccountingGroup\d\d would match 
    # AccountingGroup01, AccountingGroup02 etc
    [string]$searchString = 'accounting',
    # if true, lists all group members
    [bool]$listMembers = $true,
    # if true, regards the searchString as regex
    # if false, does a simple substring match
    [bool]$useRegEx = $false
)
  
# ======================
Clear-Host
$ErrorActionPreference = 'Stop'
# === Get all groups ===
$objSearcher = [adsisearcher]'(&(objectCategory=group))'
$objSearcher.PageSize = 20000 # may need to adjust, though should be enough for most cases
# specify properties to include
$colProplist = "name"
foreach ($i in $colPropList) { $objSearcher.PropertiesToLoad.Add($i) | out-null } 
	
$colResults = $objSearcher.FindAll()
foreach ($objResult in $colResults) {
    #group name
    $group = $objResult
    $groupname = ($objResult.Properties).name    
    
    if ($useRegEx) {
        if (-not ($groupname[0] -match $searchString)) {
            continue
        }
    }
    else {
        if (-not ($groupname[0].ToLower().Contains($searchString.ToLower()))) {
            continue
        }
    }
    Write-Host "* $groupname [$($group.Path)]"    
    if ($listMembers) {
        $Group = [ADSI]$group.Path
        $groupMembers = $Group.Member 
        if ($groupMembers.Count -eq 0) {
            Write-Host "`t(No members)"
            continue
        }
        $groupMembers | ForEach-Object {
            $Searcher = [adsisearcher]"(distinguishedname=$_)"
            $member = $searcher.FindOne()
            $userName = $member.Properties.samaccountname
            $name = $member.Properties.displayname
            Write-Host "`t[$userName]`t$name"
        }
    }
}

The second displays all details of all users whose name matches a substring.

Get-AdsiSearcherUserDetails.ps1
PowerShell
#
# Source: DotJim blog (https://dandraka.com)
# Jim Andrakakis, January 2024
#
   
# ===== Parameters =====
   
param(
    [string]$searchString = 'Papadomanolakis'
)
   
# ======================
 
Clear-Host
$ErrorActionPreference='Stop'
 
# === Get all groups ===
$objSearcher=[adsisearcher]"(&(objectClass=user)(displayname=*$($searchString)*))"
$objSearcher.PageSize = 20000 # may need to adjust, though should be enough for most cases
#$objSearcher.FindOne().Properties.Keys
$objSearcher.FindAll() | % { $_.Properties }

And the third one is a brilliant one-liner by Jos Lieben that lists all groups of a user.

Get-AdsiSearcherUserGroups.ps1
PowerShell
$userName = $env:USERNAME # change if different user needed
([ADSISEARCHER]"(member:1.2.840.113556.1.4.1941:=$(([ADSISEARCHER]"samaccountname=$userName").FindOne().Properties.distinguishedname))").FindAll().Properties.distinguishedname -replace '^CN=([^,]+).+$','$1'

Hope that helps. Enjoy! šŸ˜Š

Databases, Software, Tutorials and guides

SQL Server: How to allow access to a Windows service without a password

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Let us start by stating the obvious: password management for programs and services is a huge pain for developers.

It’s one of the things that is always overlooked during development, where you’re just trying to make the thing work. It’s even not given much attention during testing, where people are usually focused on whether it works correctly on normal uses and edge cases, they look for the UI and usability etc etc.

But come deployment time and the admins start complaining. Storing passwords in plain text files is, how to put it mildly, BLOODY HORRIBLE from a security perspective. And storing them in better ways takes a surprising amount of time –just when the devs thought they’re almost finished.

So having less passwords to store and secure is very helpful for everyone. And one thing many applications need is the credentials to a database.

Fortunately, if your application is running as a Windows service and your database is SQL server, you don’t need a password. You can use integrated security. All you need is to allow (grant) access for the service user to read data from SQL server.

Now here’s the thing: if you’re using a domain user to run the server, that’s obvious. You just create the user in SQL and grant access as needed (you can even use the script below and change the user). But what happens when, as is very common, the application is running under the Local System account?

Turns out, fortunately, there’s a solution for that as well. Every computer’s Local System account exists in Active Directory as “hostname$”. E.g. if the hostname of the application server is MYSERVER, the user name will be MYDOMAIN\MYSERVER$.

So you can run the following SQL to grant access:

/*
Source: DotJim blog (http://dandraka.com)
Jim Andrakakis, April 2023
*/

-- suppose you work on domain MYDOMAIN
-- and the server that hosts the Windows
-- service is MYSERVER
-- this is the name given by the hostname command

USE mydatabase;
GO

CREATE LOGIN [MYDOMAIN\MYSERVER$] FROM WINDOWS;
GO
CREATE USER [MYDOMAIN\MYSERVER$] FOR LOGIN [MYDOMAIN\MYSERVER$]
GO
/* db_datareader grants read-only access */
ALTER ROLE [db_datareader] ADD MEMBER [MYDOMAIN\MYSERVER$]
GO
/* if you want to insert, update or delete, add db_datawriter */
ALTER ROLE [db_datawriter] ADD MEMBER [MYDOMAIN\MYSERVER$]
GO

That done, you can use the following connection string to connect to the database:

Server=MYDBSERVER;Database=myDataBase;Trusted_Connection=yes;

or if you’re running a named instance:

Server=MYDBSERVER\MYINSTANCE;Database=myDataBase;Trusted_Connection=yes;
Databases, Software, Tutorials and guides

SQL Server: How to backup all databases with a timestamp

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I hate, hate, hate clicking and clicking again, especially for tasks that can be automated. And one of these tasks is doing DB backups, which I have to do every time before starting a deployment.

So here’s what I’ve come up with. This generates a backup for every database except the system ones (see line 20) as databasename_yyyymmdd.bak, e.g. ERP-UAT-DB_20230321.bak.

/*
Source: DotJim blog (http://dandraka.com)
Jim Andrakakis, March 2023
*/

DECLARE @name NVARCHAR(256) -- database name  
DECLARE @path NVARCHAR(512) -- path for backup files  
DECLARE @fileName NVARCHAR(512) -- filename for backup  
DECLARE @fileDate NVARCHAR(40) -- used for file name

/* specify database backup directory */
SET @path = 'D:\myBackups\'  
 
/* get date as yyyyMMdd */
SELECT @fileDate = CONVERT(NVARCHAR(20),GETDATE(),112) 
 
DECLARE db_cursor CURSOR READ_ONLY FOR  
SELECT name 
FROM master.sys.databases 
WHERE name NOT IN ('master','model','msdb','tempdb')  -- exclude these databases
AND state = 0 -- database is online
AND is_in_standby = 0 -- database is not read only for log shipping

OPEN db_cursor   
FETCH NEXT FROM db_cursor INTO @name   
 
WHILE @@FETCH_STATUS = 0   
BEGIN   
   SET @fileName = @path + @name + '_' + @fileDate + '.BAK'  
   BACKUP DATABASE @name TO DISK = @fileName  
   FETCH NEXT FROM db_cursor INTO @name   
END   
 
CLOSE db_cursor   
DEALLOCATE db_cursor

Change the path, obviously, and you can also change the WHERE name NOT IN (‘master’,’model’,’msdb’,’tempdb’). E.g. you can do something like WHERE name LIKE ‘%_PRODUCTION’ to suit your scenario.

Software, Tutorials and guides

RabbitMQ: How to publish (upload) a file to a queue via Powershell using REST

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As part of my job, this is something I use a lot. And the thing is, it’s quite easy, it’s just an Invoke-WebRequest. Here’s how I do it:

#
# Source: DotJim blog (https://dandraka.com)
# Jim Andrakakis, January 2023
#

# ===== Parameters =====

param(
    [string]$fileName = 'C:\temp\uploadinfo.json',
    [string]$rqServer = 'http://myServer:15672', # better use HTTPS though
    [string]$rqVhostName = 'myVhost',
    [string]$rqQueueName = 'myQueue',
    [string]$rqExchangeName = 'amq.default', # or your exchange name
    [string]$rqUsername = 'myUser', # this user needs at least 'Management' permissions to post to the REST API
    [string]$rqPassword = 'myPass',
	# RabbitMQ has a recommended message size limit of 128 MB
    # See https://www.cloudamqp.com/blog/what-is-the-message-size-limit-in-rabbitmq.html
    # But of course depending on your app you might want to set it lower
	[int]$rqMessageLimitMB = 128		
)

# ======================

Clear-Host
$ErrorActionPreference = 'Stop'
$WarningPreference = 'Continue'

[string]$rqUrl = "$rqServer/api/exchanges/$rqVhostName/$rqExchangeName/publish"

# Sanity check
if (-not (Test-Path $fileName)) {
    Write-Error "File $fileName was not found"
}

# Check RabbitMQ size limit
[int]$rqMessageLimit = $rqMessageLimitMB * 1024 * 1024 
[long]$fileSize = (Get-Item -Path $fileName).Length
if ($fileSize -gt $rqMessageLimit) {
    Write-Error "File $fileName is bigger that the maximum size allowed by RabbitMQ ($rqMessageLimitMB MB)"
}

$plainCredentials = "$($rqUsername):$($rqPassword)"
$encodedCredentials = [Convert]::ToBase64String([System.Text.Encoding]::UTF8.GetBytes($plainCredentials))
$authHeader = "Basic " + $encodedCredentials

[string]$content = Get-Content -Path $fileName -Encoding UTF8
$msgBase64 = [Convert]::ToBase64String([System.Text.Encoding]::UTF8.GetBytes($content))
$json = "{`"properties`":{`"content_type`":`"application/json`",`"delivery_mode`":2},`"routing_key`":`"$rqQueueName`",`"payload`":`"$msgBase64`",`"payload_encoding`":`"base64`"}"
$resp = Invoke-WebRequest -Method Post -Uri $rqUrl -Headers @{'Authorization'= $authHeader} -Body $json
if([math]::Floor($resp.StatusCode/100) -ne 2) {
    Write-Error "File $fileName could not be posted, error $($resp.BaseResponse)"
}

Write-Host "File $fileName was posted to $rqUrl"
Security, Software, Tutorials and guides

Git: how to avoid checking in secrets (using a Powershell pre-commit hook)

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Who among us hasn’t found him- or herself in this very awkward position: committing a config or code file with secrets (such as passwords or API keys) and then semi-panicked googling how to delete it from source control.

Been there and let me tell you the easiest way to delete it: copy all the code on disk, delete the repository completely and then re-create it.

(if this is not an option, well, there’s still a way but with much more work and risk, so do keep that code backup around!)

But you know what’s even better? That’s right, avoid this in the first place! That’s why Git hooks are so useful: they work without you neededing to remember to check your config files every time.

So here’s my solution to this:

  1. In the repository, go to .git/hooks and rename pre-commit.sample to pre-commit (i.e. remove the extension)
  2. Open pre-commit with a text editor and replace its contents with the following:
#!/bin/sh
C:/Windows/System32/WindowsPowerShell/v1.0/powershell.exe -ExecutionPolicy Bypass -Command '.\hooks\pre-commit.ps1'
  1. Add a new directory on the root of the repository named hooks.
  2. Inside this, add a text file named pre-commit.ps1 with the following code:
#
# Source: DotJim blog (http://dandraka.com)
# Jim Andrakakis, July 2022
#
Clear-Host
$ErrorActionPreference='Stop'

# ===== Change here =====
$listOfExtensions=@('*.xml','*.config')
$listOfSecretNodes=@('username','password','clientid','secret','connectionstring')
$acceptableString='lalala'
# ===== Change here =====

$codePath = (Get-Item -Path $PSScriptRoot).Parent.Parent.FullName

$errorList=New-Object -TypeName 'System.Collections.ArrayList'

foreach($ext in $listOfExtensions) {
    $list = Get-ChildItem -Path $codePath -Recurse -Filter $ext

    foreach($file in $list) {
        $fileName = $file.FullName
        if ($fileName.Contains('\bin\')) {
            continue
        }
        Write-Host "Checking $fileName for secrets"
        [xml]$xml=[xml]((Get-Content -Path $fileName).ToLowerInvariant())
        foreach($secretName in $listOfSecretNodes) {
            $nodes = $xml.SelectNodes("//*[contains(local-name(), '$secretName')]")
            foreach($node in $nodes) {
                if ($node.InnerText.ToLowerInvariant() -ne $acceptableString) {
                    $str = "[$fileName] $($node.Name) contains text other than '$acceptableString', please replace this with $acceptableString before commiting."
                    $errorList.Add($str) | Out-Null
                    Write-Warning $str
                }
            }
        }
    }
}

if ($errorList.Count -gt 0) {
    Write-Error 'Commit cancelled, please correct before commiting.'
}

So there you have it. I’m getting automatically stopped every time I tried to commit any .xml or .config file that contains a node with a name that contains username, password, clientid, secret or connectionstring, whenever the value of it is not ‘lalala’.

Obviously the extensions, node names and acceptable string can be changed at the top of the script. You can also change this quite easily to check JSON files as well.

Also note that this works on Windows (because of the Powershell path in the pre-commit hook) but with a minor change in the pre-commit bash script, you should be able to make it work cross-platform with Powershell core. I haven’t tested it but it should be:

#!/usr/bin/env pwsh -File '.\hooks\pre-commit.ps1'

Have fun coding!