Software Architecture and Docker

Software architecture is not something that is visible for the user and that makes it unnoticeable. But a poor software architecture can lead to the growing of a program’s cruft and makes the program hard to be modified. High internal quality, in this case a solid software architecture, leads to faster delivery of new features.

What is software architecture?

Software architecture of a program is the structure of the program system, which consists of software elements, properties of those software elements, and relationship between those two. Therefore, we can say that a software architecture of a program defines program’s structure and behaviour.

Though, it is not concerned with defining all of the structure and all of the behaviour. It is only concerned with those elements that are deemed to be significant. Significant elements are those that have a long lasting effect, such as the major structural elements, those elements associated with essential behaviour, and those elements that address significant qualities such as reliability and scalability. In general, the architecture is not concerned with the details of these software elements…

#docker #web-development

What is GEEK

Buddha Community

Software Architecture and Docker
Iliana  Welch

Iliana Welch

1595249460

Docker Explained: Docker Architecture | Docker Registries

Following the second video about Docker basics, in this video, I explain Docker architecture and explain the different building blocks of the docker engine; docker client, API, Docker Daemon. I also explain what a docker registry is and I finish the video with a demo explaining and illustrating how to use Docker hub

In this video lesson you will learn:

  • What is Docker Host
  • What is Docker Engine
  • Learn about Docker Architecture
  • Learn about Docker client and Docker Daemon
  • Docker Hub and Registries
  • Simple demo to understand using images from registries

#docker #docker hub #docker host #docker engine #docker architecture #api

Docker Architecture Overview & Docker Components [For Beginners]

If you have recently come across the world of containers, it’s probably not a bad idea to understand the underlying elements that work together to offer containerisation benefits. But before that, there’s a question that you may ask. What problem do containers solve?

After building an application in a typical development lifecycle, the developer sends it to the tester for testing purposes. However, since the development and testing environments are different, the code fails to work.

Now, predominantly, there are two solutions to this – either you use a Virtual Machine or a containerised environment such as Docker. In the good old times, organisations used to deploy VMs for running multiple applications.

So, why did they started adopting containerisation over VMs? In this article, we will provide detailed explanations of all such questions.

#docker containers #docker engine #docker #docker architecture

Fannie  Zemlak

Fannie Zemlak

1595927640

Road to Simplicity: Hexagonal Architecture [Part One]

Software writing taught me that: a well written software is a simple software.

So I started to think how to achieve simplicity in a methodological

way. This is the first story of a series about this methodology.

Naturally it’s a snapshot because it’s in constant evolution.

Simplicity

A definition of simplicity is:

The quality or condition of being easy to understand or do.

Oxford dictionary (https://www.lexico.com/en/definition/simplicity)

So, a simple software is a software that is easy to understand.

After all software are written by humans for humans. This implies

that they should be understandable. Simplicity guarantees that its

understandability isn’t an intellectual pain.

A software solves a problem. So to build the former you should understand the latter.

But to build a simple software you should understand - clearly - a problem.

First step: architecture

On the Martin Fowler blog there is a deep definition of architecture and its explanation:

“Architecture is about the important stuff. Whatever that is.”

On first blush, that sounds trite, but I find it carries a lot of richness.

It means that the heart of thinking architecturally about software is to decide what is important, (i.e. what is architectural), and then expend energy on keeping those architectural elements in good condition.

Ultimately the important stuffs are about the solved problem. In other words about the software domain.

So we need an architecture that allows us to express - clearly - the software domain.

I think that the hexagonal architecture (a.k.a. ports and adapter architecture) is an ideal candidate.

It’s based on layered architecture, so the outer layer depends on the inner layer. Each layer is represented as a hexagon.

Here a UML-like diagram to express the below concepts:

In this architecture the innermost hexagon is dedicated to the

software domain. Here we define domain objects and we express clearly:

  • what the domain does as input port or use case (I prefer the latter because expressiveness).
  • what the domain need, to fulfill use cases, as output port.

Conceptually on the sides of the domain layer there are use case and output port interfaces.

The communication between the outer layers and the domain layer happens through these interfaces.

The outer layer provides output port implementations and they use the use case interfaces.

The implementations and use case clients are are called adapter. Because they adapt our interface to a specific technology.

This relation is an instance of the dependency inversion principle. Simply put: high level concept, the domain, doesn’t rely on a specific

technology. Instead low level concept depends upon high level concept.

In other words our code is technology agnostic.

As you can see the concepts expressed in the outer layers are just details.

The real important stuff, the domain, is isolated and expressed clearly.

Code

A little project accompanies this series to show this methodology. It’s written in Java with the reactive paradigm from the beginning. For this reason the ReactiveX library is also used in the domain layer.

The software analyzes the capabilities (e.g. the java version, the

network speed and so on) of the machine and it exposes them through REST API.

It’s inspired by a real world software that I wrote because of work.

The first step is to define the innermost hexagon.

We can already identify:

  • the main use case, expressed as GetCapabilitiesUseCase
  • the object that describe the machine capabilities, expressed as Capabilities

The use case is an interface:

(if you never used ReactiveX: a Single means that the method will return asynchronously an object or an error)

public interface GetCapabilitiesUseCase {
  Single<Capabilities> getCapabilities();
}

The Capabilities objects are immutable (precisely they’re value objects). And there is an associated builder (I’m using lombok annotations to generate the code):

@RequiredArgsConstructor
@Value
@Builder
public class Capabilities {
  private final String javaVersion;
  private final Long networkSpeed;
}

#architecture #software-architecture #programming #java #hexagonal-architecture #reactive-programming #software-development #software-engineering

Custom Software vs Off-the-shelf Software: How to select a better one for your business?

Custom Software or Off-the-shelf software, the question in mind for many business personnel. Read this blog to get help to make the right decision that will benefit your business.
For a business that wants to upgrade and modernize itself with the help of software, a common dilemma it is whether to go for custom-made software or opt for off-the-shelf software. You can find many top software development companies worldwide, but before that all, you should first decide the type of software –an off-the-shelf software or a custom one.
This blog aims to overcome the dilemma and accord some clarity to a business looking to automate its business processes.

#custom software vs off-the-shelf software #custom software development companies #top software development companies #off-the-shelf software development #customized software solution #custom software development

SangKil Park

1591846392

Science and Engineering in Software Architecture

We are passing through tough times, “The moment everything changed” with COVID-19, quarantine, people trying adapt their day to day, companies not prepared to work remotely… On top of that, one thing that I have seen is a lack of science in different aspects. Lots of assumptions, lack of data and a complete chaos.

In engineering, one thing that we don’t want is chaos — WHAT?! But what about chaos mindset, chaos engineering? — don’t get me wrong, as engineers , we accept chaos and live with it, but build stable and resilient systems on top of it.

According to wikipedia, “Scientists study things by looking at them very carefully, by measuring them, and by doing experiments and tests. Scientists try to explain why things act the way they do, and predict what will happen” and also “Science uses mathematics and logic, which are sometimes called ‘formal sciences’.”, “ Science produces accurate facts, scientific laws and theories”. And as you well know, against facts there are no arguments.
Science is about exploring, experimentation, discovery and, of course, data. Please, data. Let’s base our propositions, our argues and discussions on concrete things…

#software-architecture #software-methodology #computer-science #software-improvement #software-engineering