/*

* Copyright (c) 2019 Google LLC.

*

* Licensed under the Apache License, Version 2.0 (the "License"); you may not

* use this file except in compliance with the License. You may obtain a copy of

* the License at

*

* http://www.apache.org/licenses/LICENSE-2.0

*

* Unless required by applicable law or agreed to in writing, software

* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT

* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the

* License for the specific language governing permissions and limitations under

* the License.

*/

using Microsoft.AspNetCore.Builder;

using Microsoft.Extensions.Configuration;

using Microsoft.Extensions.DependencyInjection;

using Microsoft.Extensions.Hosting;

using Npgsql;

using Polly;

using System;

using System.Data.Common;

namespace CloudSql

{

public class Startup

{

public IConfiguration Configuration { get; }

public Startup(IConfiguration configuration)

{

Configuration = configuration;

}

// This method gets called by the runtime. Use this method to add

// services to the container.

// For more information on how to configure your application, visit

// http://go.microsoft.com/fwlink/?LinkID=398940

public void ConfigureServices(IServiceCollection services)

{

services.AddSingleton(sp => StartupExtensions.GetPostgreSqlConnectionString());

services.AddMvc(options =>

{

options.Filters.Add(typeof(DbExceptionFilterAttribute));

});

services.AddMvc(option => option.EnableEndpointRouting = false);

}

// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.

public void Configure(IApplicationBuilder app, IHostEnvironment env)

{

if (env.IsDevelopment())

{

app.UseDeveloperExceptionPage();

}

else

{

// Configure error reporting service.

app.UseExceptionHandler("/Home/Error");

}

app.UseMvc(routes =>

{

routes.MapRoute(

name: "default",

template: "{controller=Home}/{action=Index}/{id?}");

});

}

}

static class StartupExtensions

{

public static void OpenWithRetry(this DbConnection connection) =>

// [START cloud_sql_postgres_dotnet_ado_backoff]

Policy

.Handle<NpgsqlException>()

.WaitAndRetry(new[]

{

TimeSpan.FromSeconds(1),

TimeSpan.FromSeconds(2),

TimeSpan.FromSeconds(5)

})

.Execute(() => connection.Open());

// [END cloud_sql_postgres_dotnet_ado_backoff]

public static void InitializeDatabase()

{

var connectionString = GetPostgreSqlConnectionString();

using(DbConnection connection = new NpgsqlConnection(connectionString.ConnectionString))

{

connection.OpenWithRetry();

using (var createTableCommand = connection.CreateCommand())

{

createTableCommand.CommandText = @"

CREATE TABLE IF NOT EXISTS

votes(

vote_id SERIAL NOT NULL,

time_cast timestamp NOT NULL,

candidate CHAR(6) NOT NULL,

PRIMARY KEY (vote_id)

)";

createTableCommand.ExecuteNonQuery();

}

}

}

public static NpgsqlConnectionStringBuilder GetPostgreSqlConnectionString()

{

NpgsqlConnectionStringBuilder connectionString;

if (Environment.GetEnvironmentVariable("INSTANCE_HOST") != null)

{

connectionString = PostgreSqlTcp.NewPostgreSqlTCPConnectionString();

}

else

{

connectionString = PostgreSqlUnix.NewPostgreSqlUnixSocketConnectionString();

}

// The values set here are for demonstration purposes only. You

// should set these values to what works best for your application.

// [START cloud_sql_postgres_dotnet_ado_limit]

// MaxPoolSize sets maximum number of connections allowed in the pool.

connectionString.MaxPoolSize = 5;

// MinPoolSize sets the minimum number of connections in the pool.

connectionString.MinPoolSize = 0;

// [END cloud_sql_postgres_dotnet_ado_limit]

// [START cloud_sql_postgres_dotnet_ado_timeout]

// Timeout sets the time to wait (in seconds) while

// trying to establish a connection before terminating the attempt.

connectionString.Timeout = 15;

// [END cloud_sql_postgres_dotnet_ado_timeout]

// [START cloud_sql_postgres_dotnet_ado_lifetime]

// ConnectionIdleLifetime sets the time (in seconds) to wait before

// closing idle connections in the pool if the count of all

// connections exceeds MinPoolSize.

connectionString.ConnectionIdleLifetime = 300;

// [END cloud_sql_postgres_dotnet_ado_lifetime]

return connectionString;

}

}

}