A programming exercise that accessess Mars Rover images from the Nasa API portal, saves them, and serves them in a web api.

The MarsRoverApi project downloads data about the Nasa Mars Rovers from the Nasa API portal.

The application is divided into the following projects.

The following is preformed on startup:

1. Retrieves a list of rover information along with the cameras used on each rover from the Nasa API portal.
   • The list of rovers with their associated cameras are saved in a database.
   • Initialization of rover information is only done once at the beginning of the first start of the web api.
2. Dates are read from a local file, one date at a time.
   • The dates are validated as they are read.
   • The service that reads the dates uses IEnumerable and yield, allowing the application to loop through the dates, reading only one date at a time and not needing to keep a list in memory.
3. For each rover and date combination, the Nasa API portal is called.
   • Calls to the Nasa API portal use paged retrieval accessing 25 items per page.
   • Information about each image is saved to a database.
   • For each image, a call is made to the Nasa Image api to retrieve the image.
   • Each image is saved locally in a file.
   • Initialization of Mars Rover photo images is only done once at the beginning of the first start of the web api. Data that has already been saved is not retrieved from Nasa again.

This application is a Web Api. It provides API endpoints that can be called from client applications to retrieve data and images that have been retrieved from Nasa.

An example of a client application that calls this API can be found at: MarsRoverAngularUi

GET "http://localhost:8563/api/Dates"
GET "http://localhost:8563/api/Rovers"
GET "http://localhost:8563/api/Rovers/5"
GET "http://localhost:8563/api/Rovers/5/photos/2017-02-27?page=1&pagesize=10"
GET "http://localhost:8563/api/Images/MarsRoverImages/FLB_541484941EDR_F0611140FHAZ00341M_.JPG"

• C#
• .NET Core 5
• Entity Framework Core 5
  • EF Core Migrations
  • Paged Query Results
• Swagger
• .NET Core Logging
• xUnit Tests
• JSon Serialization (for .NET Core 5)
• HttpClient
• yield keyword
• File and Stream IO
• Dependency Injection
• CORS
• SqlLite
• Extension Methods

This project is written in C# using .Net Core 5.0.

The following NuGet packages are used:

Microsoft.EntityFrameWorkCore
Additional information can be found here

Microsoft.EntityFrameWorkCore.Sqlite
Additional information can be found here

Swashbuckle.AspNetCore Additional information can be found here

Automapper Documentation about automapper can be found at the Automapper Office Website

Download or clone this repository.

Note: The first time this application runs, it can take several minutes to load all the mars rover images from the Nasa API portal.

1. Open the solution in Visual Studio.
2. Build the solution.
3. Run the solution (either in debug or non-debug mode).

The application will open in your browser using "http://localhost:8563".

You can explore the Web API features using the Swagger page. "http://localhost:8563/swagger/index.html"

This project is licensed with the MIT license.