# Let`s zoom in on my first assignment # Previously on... I finished up my previous series about how I started to explore the consultant side of the IT sector. This blog post starts a new series. Below you can find a bullet list of what is used in this project. The topics on which I'll be blogging are DevOps, Analyses, Development, Acceptance Environments, Documentation and Knowledge sharing. This way, I have some structure on what I can write about next. Through this, I want to inspire others or have discussions about why other approaches can be more beneficial. # Context I help deliver a project that will enable a user to signup into the customer portal using a registration system. The customer asked me to develop two Web App services that are functioning as REST APIs. When a user signs up, he will have two options: * using Auth0 and ItsMe, so the user can be verified using the ItsMe app * using personal data with verification sent by sms or email. ## Technology used ### DevOps I do not have access to create pipelines and resources in [Azure DevOps](https://azure.microsoft.com/nl-nl/products/devops). However, I do function as a lead for my services so I do work closely with the DevOps persons when problems arise or information is needed. * All services make use of continuous integration as well as continuous development. The customer describes what branching strategy I should use. * The entire solution is deployed using [Web App ASE on Azure](https://learn.microsoft.com/en-us/azure/app-service/environment/intro). ### Analysis This has already been done by the enterprise architect and the business analyst. What I did was help with: * Clarifications and documents to reflect what is development * Challenging content of [access tokens](https://oauth.net/2/access-tokens/) * Challenging REST-call signatures ### Development The setup of the solution consists of a service-oriented architecture. With some good faith, you can see some resemblance with the microservice-oriented architecture. * Backend services make use of [Asp.net core version 6.0](https://learn.microsoft.com/en-us/aspnet/core/?view=aspnetcore-6.0) using [swagger](https://swagger.io/) as documentation. * The user interface makes use of [Asp.net core MVC 6](https://learn.microsoft.com/en-us/aspnet/core/?view=aspnetcore-6.0) and [swagger](https://swagger.io/). * The services can only talk to each other when using [Azure API Management](https://azure.microsoft.com/en-us/products/api-management). * Secrets should be handled with care using [Azure Key vault](https://azure.microsoft.com/en-us/products/key-vault/). For local development, [secrets are not checked in the repository](https://learn.microsoft.com/en-us/aspnet/core/security/app-secrets?view=aspnetcore-7.0&tabs=windows). * All consumers should identify themself using [Oauth2](https://www.rfc-editor.org/rfc/rfc6749). Claims are used for authorization. For some legacy services, certificates are used for authorization. * I use validation using [FluentValidation](https://www.nuget.org/packages/FluentValidation.AspNetCore/). An [extension](https://github.com/micro-elements/MicroElements.Swashbuckle.FluentValidation) for integrating FluentValidation with Swagger is used. Attributes are used as less as possible to have clean data transfer objects. * In the core of the REST services, a domain is created. However, I would not call this [domain driven design](https://en.wikipedia.org/wiki/Domain-driven_design). * [Separation of concern](https://medium.com/machine-words/separation-of-concerns-1d735b703a60) ( and layers ) is enforced using the use of mappers. * The package [Polly](https://www.nuget.org/packages/polly/) is used when libraries do not retry on Http Status Code 429. * Exceptions are there when unexpected technical behaviour occurs. I made use of [CSharpFunctionalExtensions](https://github.com/vkhorikov/CSharpFunctionalExtensions) nuget-package to have support for validation during the whole flow. * Configuration happens using appsettings.json and using the [IOptionsMonitor](https://learn.microsoft.com/en-us/dotnet/core/extensions/options). [AzureKeyvault extensions](https://www.nuget.org/packages/Azure.Extensions.AspNetCore.Configuration.Secrets/) are enabled. * Classes are marked as [internal and sealed](https://www.youtube.com/watch?v=d76WWAD99Yo) where possible for performance gaining. * [Newtonsoft.json is used as less as possible](https://learn.microsoft.com/en-us/dotnet/standard/serialization/system-text-json/migrate-from-newtonsoft?pivots=dotnet-7-0). The one that should be used the most is System.Text.Json * [Dependency Injection is used](https://learn.microsoft.com/en-us/dotnet/core/extensions/dependency-injection) * Logging is enabled using the native [Application Insights](https://learn.microsoft.com/en-us/azure/azure-monitor/app/app-insights-overview?tabs=net) library package. For local logging, The NuGet package [NLog](https://nlog-project.org/) is used with [Microsoft](https://github.com/NLog/NLog.Extensions.Logging) Extensions. ### Acceptance Environments The business analyst will validate the services using SoapUI and PostMan. Whenever an error occurs, extra system tests and/or unit tests are written. ### Documentation The analysis needs to reflect what is going to be developed, as well as what is developed. However, I make it my mission to put as much of the documentation in swagger. ### [Knowledge sharing](https://xpirit.com/dna/) * Each week, there is one hour that the .Net developers on the project meet to exchange strange issues, nice discoveries and so on. * Using the [4 eyes principle](https://ec.europa.eu/eurostat/cros/content/four-eyes-principle_en#:~:text=The%20Four%20eyes%20principle%20is,or%20the%20two%2Dperson%20rule.), we can help out each other. * When there is some discussion where the customer does want to have some answer, I do talk to my XPirit colleagues about it. After having the discussion, I write a concise email to the customer with the problem and how we recommend approaching this. # Outro With this post, I have mentioned a lot of technologies, architectures, and ways of working that I will explain more about in the next posts. Let me know what topic you want to know more off in this context.