Implementation of a basic Go web server emulating the backend of a simple CRM application written as a final project for the Udacity Golang Course.

The project consists of a web server written in the Go language which after started serves a REST API to which users can make HTTP requests using utilities like Postman or cURL. The application provides the following five endpoints to which users can make CRUD operations to the CRM application:

These CRUD operations interact with the CRM application in order to create, retrieve, update and delete customers from the CRM, and each of these endpoints is assigned to its appropriate HTTP method (GET, POST, PUT, DELETE) by leveraging a custom HTTP method-based router.

The application runs "in-memory" and does not implement any mechanism for persisting the customers data after the server is stopped. Internally, the application stores the customers data in a Go map, which serves as the database of the CRM.

As a note, the application just serves a backend API and does not have any frontend other than a static welcome page located at the home route of the server.

In order to run the application, the Go language needs to be installed. The application was written in the version 1.19.3 of Go, but it should work with any recent version of the language. You can download Go here.

After installing Go, a proper local Go Workspace directory structure needs to be established inside the GOPATH directory. For this, you need to first check the value of the GOPATH environment variable, which contains the path where the Go Workspace needs to be located. To do this, open any terminal of the operating system you are using and run the following command:

go env GOPATH

The output will be something like "C:\Users\UserName\go". It can be that the go folder is not already created in that directory, if not then create it. After this, please ensure that the following directory structure is there inside the go folder:

go\ <--- root of the go folder
├── bin\
├── pkg\
└── src\
    └── github.com\
        └── saulhdez\

Next, inside the saulhdez folder, either clone this repo or download it and unzip it there. The final directory structure should look like this:

go\
├── bin\
├── pkg\
└── src\
    └── github.com\
        └── saulhdez\
            └── Go-CRM-Backend\

Now, in order for the application to compile and run, the two following third-party Go packages need to be installed:

• gorilla/mux package, which provides a custom HTTP router (or mux) able to perform HTTP method-based routing.
• Google's uuid package, required to provide each of the CRM customers with an UUID.

To install them, open a terminal and navigate to the root directory of the CRM Backend project, which is the root of the "Go-CRM-Backend" folder. Then run the following two go get commands, one for each of the required packages, this will install them and make them available to be used in the application code:

go get github.com/gorilla/mux
go get github.com/google/uuid

Finally, in order to interact with the application as a user, you will need any utility software that allows you to make requests to a REST API. Postman or cURL are good options, you can download them using those links.

To start the application, open a terminal and navigate to the root directory of the CRM Backend project, where the main.go file is located. Then, run the following command:

go run main.go

This will start the server and make it start to listen for requests at port 3000, which is the default (hardcoded) port for the server. In case you require to change the default port, you can change it in the main.go file using any code editor of your preference, like Visual Studio Code, Sublime Text, etc.

After the server is started, the application can be accessed through http://localhost:3000 and REST requests can start to be made to its different API endpoints. As stated before, the home route of the server will serve an static HTML welcome page. In this page you can view the documentation of the REST API, which specifies the format of the JSON payloads that the API expects to receive and the way in which to pass URL variables for each of the API endpoints.

Located at the root directory of the CRM Backend project is the main_test.go file. This is a Go file containing basic unit tests for the CRM application, which just test that correct HTTP status codes and Content-Types are returned by the different API endpoints of the application in the server responses. This file is not of my authorship and was downloaded from the Resources section of the Udacity Golang Course.