Startup.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Identity.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.PlatformAbstractions;
using oahu_api.Models;
using Swashbuckle.AspNetCore;
using Swashbuckle.AspNetCore.Swagger;
using Swashbuckle.AspNetCore.SwaggerGen;

namespace oahu_api
{
    public class Startup
    {
        public Startup(IHostingEnvironment env)
        {
            var builder = new ConfigurationBuilder()
                .SetBasePath(env.ContentRootPath)
                .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
                .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true)
                .AddEnvironmentVariables();
            Configuration = builder.Build();
        }

        public IConfigurationRoot Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        #region snippet_AddSingleton
        public void ConfigureServices(IServiceCollection services)
        {
            var sqlConnectionString = Environment.GetEnvironmentVariable("PostgresString");
            services.AddDbContext<PgContext>(options =>
                options.UseNpgsql(sqlConnectionString)
            );

            services.AddCors(options =>
            {
                options.AddPolicy("AllowAllOrigins",
                builder => builder.AllowAnyOrigin());
            });

            services.AddMvc();

            var pathToDoc = Environment.GetEnvironmentVariable("SwaggerXmlFile");
            services.AddSwaggerGen();
            services.ConfigureSwaggerGen(options =>
            {
                options.SwaggerDoc("v1",
                    new Info
                    {
                        Title = "MoTI IoT API",
                        Version = "v1",
                        Description = "A simple api to access IoT devices",
                        TermsOfService = "None"
                    }
                 );

                var filePath = Path.Combine(PlatformServices.Default.Application.ApplicationBasePath, pathToDoc);
                options.IncludeXmlComments(filePath);
                options.DescribeAllEnumsAsStrings();
            });

            // Add application services.
            services.AddSingleton<IDeviceRepository, DeviceRepository>();
            services.AddSingleton<IEventRepository, EventRepository>();
        }
        #endregion

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
        {
            loggerFactory.AddConsole(Configuration.GetSection("Logging"));
            loggerFactory.AddDebug();

            app.UseMvc();
            app.UseSwagger(c =>
            {
                c.PreSerializeFilters.Add((swagger, httpReq) => swagger.Host = httpReq.Host.Value);
            });

            app.UseSwaggerUi(c =>
            {
                c.SwaggerEndpoint("/swagger/v1/swagger.json", "V1 Docs");
            });
        }
    }
}