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Month: October 2023

Categories
.Net C#

Dapper for data access in C# part 2

In the past, I have written about A quick introduction to Dapper! This blog article is a continuation:

The most popular ways to access data in .Net are:

  1. ADO.Net
  2. Entity Framework
  3. 3rd party ORMs such as Dapper

ADO.Net needs a lot of code i.e opening IDataReader, iterating, reading elements and mapping etc… Similarly when calling Stored Procedures, adding params etc…

EntityFramework is a great choice for a lot of different situations.

When connecting to RDBMS such as SQL Server, MySQL, I prefer StoredProcs over dynamically generated SQL for several reasons. Consider this as part of some best practices from security and performance reasons rather than ease of code. In the past, I have been responsible and represented audits from development team perspective.

The 3rd choice – 3rd party ORMs and Micro ORMs. Dapper is a micro ORM. Dapper has excellent performance and probably the most suitable when handling Stored Procedures. Dapper supports many different RDBMS types.

Even Dapper call’s can be easily wrapped around and logging etc… can be done. Almost all the methods accept optional Transaction for wrapping multiple calls in a single transaction.

https://www.learndapper.com/ has excellent documentation.

Some of the nicer features of Dapper are:

  1. No need of strongly typed objects
  2. Multiple RDBMS support
  3. Ability to read multiple resultsets

Some code samples (MySQL example):

using Dapper;

using (var connection = new MySqlConnection(connectionString))
{
    await connection.OpenAsync();
    await connection.ExecuteAsync(
       "STORED_PROC_NAME", 
       new {
          varParam1 = "value1",
          varParam2 = 1
       }, null, null, CommandType.StoredProcedure);
}

Some of the other useful methods are:

connection.ExecuteReaderAsync //For any reason, if you need IDataReader

ExecuteScalar // For single object
            // or
ExecuteScalar<T> //For single object of type T
            // or
ExecuteScalarAsync(), ExecuteScalaAsync<T>() // The async equivalents

Query()
QueryFirst()
QueryFirstOrDeafult()
QuerySingle()

BTW, combining these with Polly and creating robust wrappers would be a recommended approach.

Polly library for writing resilient .Net code

–

Mr. Kanti Kalyan Arumilli

Arumilli Kanti Kalyan, Founder & CEO
Arumilli Kanti Kalyan, Founder & CEO

B.Tech, M.B.A

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Founder & CEO, Lead Full-Stack .Net developer

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ALight Technologies USA Inc

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Phone / SMS / WhatsApp on the following 3 numbers:

+91-789-362-6688, +1-480-347-6849, +44-07718-273-964

+44-33-3303-1284 (Preferred number if calling from U.K, No WhatsApp)

kantikalyan@gmail.com, kantikalyan@outlook.com, admin@alightservices.com, kantikalyan.arumilli@alightservices.com, KArumilli2020@student.hult.edu, KantiKArumilli@outlook.com and 3 more rarely used email addresses – hardly once or twice a year.

Categories
Security Tailscale VPN

A review and discussion of the free tier of Tailscale-2

This blog post is a continuation of: https://www.alightservices.com/2023/10/30/a-review-and-discussion-of-the-free-tier-of-tailscale/

In my own startups – ALight Technology And Services Limited (U.K) ALight Technologies USA Inc (U.S.A) I do everything from end-to-end i.e coming up with ideas, analysing value proposition, deciding on features, feature prioritization, cloud architecture, technical architecture, actual development, some sanity checks, deployment with the help of some CI/CD tools based in the cloud and blog articles in the open internet. I have been evaluating and experimenting with various methods of securely accessing cloud workloads.

I have tried few more things after writing the above mentioned blog post:

MagicDNS and Serve: Definitely useful feature for quick demos or prototypes.

SSH: SSH via Tailscale, did not trigger my alerts. I have configured and developed my own monitoring and alerting system based on NIST CyberSecurity Framework. When I SSH’ed via Tailscale by advertising node by passing –ssh these did not get triggered. The reason could be because Tailscale SSH does not use port 22 and that’s why port does not need to be opened. This option did not even require the .pem or password because SSH is being done directly inside of Tailscale rather than normal port 22.

I have not tried SSH without –ssh option i.e normal ssh while connected to VPN overlay yet.

I have uninstalled Tailscale and I might make further trials later or tomorrow.

BTW in my own startups – ALight Technology And Services Limited (U.K) ALight Technologies USA Inc (U.S.A) I do everything from end-to-end i.e coming up with ideas, analysing value proposition, deciding on features, feature prioritization, cloud architecture, technical architecture, actual development, some sanity checks, deployment with the help of some CI/CD tools based in the cloud and blog articles in the open internet.

–

Mr. Kanti Kalyan Arumilli

Arumilli Kanti Kalyan, Founder & CEO
Arumilli Kanti Kalyan, Founder & CEO

B.Tech, M.B.A

Facebook

LinkedIn

Threads

Instagram

Youtube

Founder & CEO, Lead Full-Stack .Net developer

ALight Technology And Services Limited

ALight Technologies USA Inc

Youtube

Facebook

LinkedIn

Phone / SMS / WhatsApp on the following 3 numbers:

+91-789-362-6688, +1-480-347-6849, +44-07718-273-964

+44-33-3303-1284 (Preferred number if calling from U.K, No WhatsApp)

kantikalyan@gmail.com, kantikalyan@outlook.com, admin@alightservices.com, kantikalyan.arumilli@alightservices.com, KArumilli2020@student.hult.edu, KantiKArumilli@outlook.com and 3 more rarely used email addresses – hardly once or twice a year.

Categories
Security Tailscale VPN

A review and discussion of the free tier of Tailscale

Tailscale is a SaaS product offering, enabling easy VPN networks of scale on top of WireGuard. I have been using Tailscale for 2 – 3 months now and I plan to use more Tailscale features soon. This article is not a hands on guide, but more of a discussion on the features.

Someday I might upgrade to the paid plans.

Simple and straightforward installation, setup and thorough documentation.

Tailscale machines can be registered in the network, removed from the console. By default machines need to be registered every 24 hours, but if needed key expiry can be disabled.

By registering machines, the machines are registered in an overlay network and can communicate. The communications, user-access can be configured via policies. I think it’s very important to use –shields-up argument with tailscale up on client machines where we don’t want inbound connections. Considering the anonymous mafia equipment, I think there is a small loophole where a hacker might temporarily gain control a server in some scenarios – I have reported and suggested an alternative way: https://github.com/tailscale/tailscale/issues/8823

tailscale up --shields-up

VPN via exit node:

Although not the primary use-case, one of the Tailscale nodes can be configured as exit-nodes and can be used as VPN with very minimal configuration. This is one of the features, I have been using. I have a exit node in AWS in London region and I use the exit node like a VPN. The reason, I liked this feature is because, I don’t need to open any ports to the public internet or even for my own IP.

SSH:

Another useful feature, for semi-secure environments such as Development / QA could be SSH. Without opening the ports SSH can be done through Tailscale portal. I have used this feature few times.

WebHook Alerts: Webhook alerts can be used for getting notifications. I have configured Slack for alerts.

Some features, I haven’t tried yet but plan to:

Lock: Locks allow key signing from trusted internal nodes.

MagicDNS: MagicDNS allows an internal DNS. Should be useful for Dev / QA environments, internal applications etc…

Cert: Allows generating certificates based on MagicDNS i.e internal applications can be accessed securely using SSL.

Serve: Spin up a web-server. This can be done from command-line for some quick tests / validations without worrying about web server configurations in Dev / QA environments. For longer-term, I think configuring NGinx / Apache / IIS would be more useful.

SSH Session Recording: This is a paid feature but definitely useful i.e SSH sessions via Tailscale can be recorded.

Tailscale has extensive documentation and should be straightforward for most users.

–

Mr. Kanti Kalyan Arumilli

Arumilli Kanti Kalyan, Founder & CEO
Arumilli Kanti Kalyan, Founder & CEO

B.Tech, M.B.A

Facebook

LinkedIn

Threads

Instagram

Youtube

Founder & CEO, Lead Full-Stack .Net developer

ALight Technology And Services Limited

ALight Technologies USA Inc

Youtube

Facebook

LinkedIn

Phone / SMS / WhatsApp on the following 3 numbers:

+91-789-362-6688, +1-480-347-6849, +44-07718-273-964

+44-33-3303-1284 (Preferred number if calling from U.K, No WhatsApp)

kantikalyan@gmail.com, kantikalyan@outlook.com, admin@alightservices.com, kantikalyan.arumilli@alightservices.com, KArumilli2020@student.hult.edu, KantiKArumilli@outlook.com and 3 more rarely used email addresses – hardly once or twice a year.

Categories
.Net C# Logging NLog

Custom Layout Renderer for NLog using C# New

In a previous blog post – Custom Layout Renderer for NLog using C#, I have mentioned about how to create a class inheriting LayoutRenderer and writing custom Layout Renderer.

This blog post talks about inheriting from WrapperLayoutRendererBase class.

The WrapperLayoutRendererBase class has a method with the signature:

protected override string Transform(string text)

This method needs to be overridden. The nice thing about using this class is other layout renderers can be used in combination.

Here is a GitHub repo implementing hash functions that can be used as LayoutRenderers.

https://github.com/ALightTechnologyAndServicesLimited/ALight.NLog.LayoutRenderer.Hash

The source code has 4 projects:

  1. The actual implementation
  2. Unit Tests
  3. Benchmark Tests
  4. Example

The usage is straightforward, use hash or securehash layout renderer.

  <extensions>
    <add assembly="ALight.NLog.LayoutRenderer.Hash" />
  </extensions>




<target xsi:type="File" name="logfile" fileName="c:\temp\console-example.log"
        layout="${longdate}|${level}|${message} |${all-event-properties} ${exception:format=tostring} ${hash:hello} 
        ${securehash:value=${level}} ${event-properties:item=secret} ${hash:${event-properties:item=secret}} ${hash:${level}}" />

The hash implementation is about 10 – 11 times faster but uses Murmur3 non cryptographic hash.

I might consider a nuget package at a later point, but not now, because the code is very minimal and like a small helper class.

–

Mr. Kanti Kalyan Arumilli

Arumilli Kanti Kalyan, Founder & CEO
Arumilli Kanti Kalyan, Founder & CEO

B.Tech, M.B.A

Facebook

LinkedIn

Threads

Instagram

Youtube

Founder & CEO, Lead Full-Stack .Net developer

ALight Technology And Services Limited

ALight Technologies USA Inc

Youtube

Facebook

LinkedIn

Phone / SMS / WhatsApp on the following 3 numbers:

+91-789-362-6688, +1-480-347-6849, +44-07718-273-964

+44-33-3303-1284 (Preferred number if calling from U.K, No WhatsApp)

kantikalyan@gmail.com, kantikalyan@outlook.com, admin@alightservices.com, kantikalyan.arumilli@alightservices.com, KArumilli2020@student.hult.edu, KantiKArumilli@outlook.com and 3 more rarely used email addresses – hardly once or twice a year.

Categories
.Net C# Logging NLog

Custom Layout Renderer for NLog using C#

*** use WrapperLayoutRendererBase instead of LayoutRenderer, this blog post is about LayoutRenderer ***

NLog has lot of built-in layout renderers. Here is a list of official layout renderers:

https://nlog-project.org/config/?tab=layout-renderers

Creating custom layout renderer is very simple and straight-forward. Here is the official documentation:

https://github.com/NLog/readthedocs/blob/master/docs/How-to-write-a-custom-layout-renderer.md

There are 2 ways:

Lambda:

LayoutRenderer.Register("name", (logEvent, config) => "Message");

In the above scenarion, we can use ${name} when defining a layout, of course instead of returning static string we can do something useful based on the use-case.

Class:

Define a new class inherited from NLog.LayoutRenderers.LayoutRenderer. Use class attribute LayoutRenderer(“name”). LayoutRenderer is an abstract class, implement the class by overriding Append(StringBuilder builder, LogEventInfo logEvent) method i.e Append the value that needs to be added to the log by appending to the StringBuilder parameter.

[LayoutRenderer("Example")]
public class ExampleLayoutRenderer : NLog.LayoutRenderers.LayoutRenderer
{
    public string Value { get; set; }

    protected override void Append(StringBuilder builder, LogEventInfo logEvent)
    {
        builder.Append("Value");
    }
}

Extra parameters can be passed and assigned as properties of the custom class.

[LayoutRenderer("example")]
public class ExampleLayoutRenderer : NLog.LayoutRenderers.LayoutRenderer
{
    public string Value { get; set; }

    protected override void Append(StringBuilder builder, LogEventInfo logEvent)
    {
        // Your custom code
        builder.Append(Value);
    }
}

In the config file the custom layout renderer with params can be used like follows:

{example}

{example:value=abc}

Sometimes, in logs we write some data that might be needed for identifying but not necessarily the real value and for various reasons we might just need a hash. For example: SessionId / Some Cookie Value / IP address etc… Having a custom renderer for hashing such a value could be used.

Very few lines of code, i.e hashing and appending to a stringbuilder would solve the need i.e 2 – 3 lines of code. But, I think the 2 – 3 lines of code could be helpful for other people. I am considering creating an opensource version. I might or might not release nuget package. If I release nuget package, I would definitely make an anouncement. Anyway, not a big open-source project, but just few lines of code.

–

Mr. Kanti Kalyan Arumilli

Arumilli Kanti Kalyan, Founder & CEO
Arumilli Kanti Kalyan, Founder & CEO

B.Tech, M.B.A

Facebook

LinkedIn

Threads

Instagram

Youtube

Founder & CEO, Lead Full-Stack .Net developer

ALight Technology And Services Limited

ALight Technologies USA Inc

Youtube

Facebook

LinkedIn

Phone / SMS / WhatsApp on the following 3 numbers:

+91-789-362-6688, +1-480-347-6849, +44-07718-273-964

+44-33-3303-1284 (Preferred number if calling from U.K, No WhatsApp)

kantikalyan@gmail.com, kantikalyan@outlook.com, admin@alightservices.com, kantikalyan.arumilli@alightservices.com, KArumilli2020@student.hult.edu, KantiKArumilli@outlook.com and 3 more rarely used email addresses – hardly once or twice a year.