Add nginx-aspnet-mysql implementation (#119)

* Added nginx-aspnet-mysql implementation

Signed-off-by: GitHub <noreply@github.com>

* Updated nginx+aspnet+mysql README.md

Signed-off-by: GitHub <noreply@github.com>

* Added db healthcheck

Signed-off-by: GitHub <noreply@github.com>

nginx-aspnet-mysql/backend/Program.cs

@@ -0,0 +1,84 @@
+using System;
+using System.IO;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore;
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Hosting;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Routing;
+using Microsoft.Extensions.Primitives;
+using MySql.Data;
+using MySql.Data.MySqlClient;
+
+class Program
+{
+    public static void Main(string[] args)  => WebHost.CreateDefaultBuilder(args)
+        .Configure(async app =>
+        {
+            app.UseRouting();
+                    
+            string password = File.ReadAllText("/run/secrets/db-password");
+            string connectionString = $"server=db;user=root;database=example;port=3306;password={password}";
+
+            app.UseEndpoints(e =>
+            {
+                e.MapGet("/",  context => {
+                    using MySqlConnection connection = new MySqlConnection(connectionString);
+                    var titles = new List<string>();
+
+                    try
+                    {
+                        Console.WriteLine("Connecting to MySQL...");
+                        connection.Open();
+
+                        string sql = "SELECT title FROM blog";
+                        using var cmd = new MySqlCommand(sql, connection);
+                        using MySqlDataReader reader = cmd.ExecuteReader();
+
+                        while (reader.Read())
+                        {
+                            titles.Add(reader.GetString(0));
+                        }
+                        reader.Close();
+                    }
+                    catch (Exception ex)
+                    {
+                        Console.WriteLine(ex.ToString());
+                        context.Response.StatusCode = 500;
+                        return Task.CompletedTask;
+                    }
+                    connection.Close();
+                    
+                    context.Response.StatusCode = 200;
+                    context.Response.WriteAsJsonAsync(titles);
+
+                    return Task.CompletedTask;
+                });
+            });
+            Prepare(connectionString);
+
+        }).Build().Run();
+
+        private static void Prepare(string connectionString)
+        {
+            using MySqlConnection connection = new MySqlConnection(connectionString);
+
+            connection.Open();
+            using var transation = connection.BeginTransaction();
+
+            using MySqlCommand cmd1 = new MySqlCommand("DROP TABLE IF EXISTS blog", connection, transation);
+            cmd1.ExecuteNonQuery();
+
+            using MySqlCommand cmd2 = new MySqlCommand("CREATE TABLE IF NOT EXISTS blog (id int NOT NULL AUTO_INCREMENT, title varchar(255), PRIMARY KEY (id))", connection, transation);
+            cmd2.ExecuteNonQuery();
+            
+            for (int i = 0; i < 5; i++)
+            {
+                using MySqlCommand insertCommand = new MySqlCommand( $"INSERT INTO blog (title) VALUES ('Blog post #{i}');", connection, transation);
+                insertCommand.ExecuteNonQuery();
+	        }
+            transation.Commit();
+            connection.Close();
+        }
+}