Heroku .NET Core Buildpack

This is the Heroku buildpack for ASP.NET Core.

The Buildpack supports C# and F# projects. It searchs through the repository's folders to locate a Startup.* or Program.* file. If found, the .csproj or .fsproj in the containing folder will be used in the dotnet publish <project> command.

If repository contains multiple Web Applications (multiple Startup.* or Program.*), PROJECT_FILE and PROJECT_NAME environment variables allow to choose project for publishing.

heroku buildpacks:set jincod/dotnetcore

heroku buildpacks:set https://github.com/jincod/dotnetcore-buildpack

heroku buildpacks:set https://github.com/jincod/dotnetcore-buildpack#preview

heroku buildpacks:set https://github.com/jincod/dotnetcore-buildpack#version

Available releases

More info

• Heroku Buildpack Registry
• Buildpack references

You cannot run migrations with the dotnet ef commands using .NET Local Tools once the app is built. Alternatives include:

• Ensure there is a .NET local tool manifest file(dotnet-tools.json) which specifies the dotnet-ef tool:

dotnet new tool-manifest
dotnet tool install dotnet-ef

• Ensure the ASPNETCORE_ENVIRONMENT environment variable is set to Production. ASP.NET Core scaffolding tools may create files that explicitly set it to Development. Heroku config will override this (heroku config:set ASPNETCORE_ENVIRONMENT=Production).
• Configure your app to automatically run migrations at startup by adding the following to the .csproj file:

<Target Name="PrePublishTarget" AfterTargets="Publish">
  <Exec Command="dotnet ef database update" />
</Target>

• Manually run SQL scripts generated by Entity Framework Core in your app's database. For example, use PG Admin to connect your Heroku Postgres service.

If you are using Heroku Postgres addon, then Heroku provides the database connection string as environment variable DATABASE_URL. In order to use this in an Npgsql connection string, do something like following:

using System.Text.RegularExpressions;

...

// Replace AppContext with your own DbContext Class
builder.Services.AddDbContext<AppContext>(options =>
{
  if (Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT") == "Production")
  {
    var m = Regex.Match(Environment.GetEnvironmentVariable("DATABASE_URL")!, @"postgres://(.*):(.*)@(.*):(.*)/(.*)");
    options.UseNpgsql($"Server={m.Groups[3]};Port={m.Groups[4]};User Id={m.Groups[1]};Password={m.Groups[2]};Database={m.Groups[5]};sslmode=Prefer;Trust Server Certificate=true");
  } 
  else // In Development Environment
  {
    // So, use a local Connection
    options.UseNpgsql(builder.Configuration.GetValue<string>("CONNECTION_STRING"));
  }
});

heroku buildpacks:set jincod/dotnetcore
heroku buildpacks:add --index 1 heroku/nodejs

Using Multiple Buildpacks for an App

heroku config:set HEROKUISH=true

If you have multiple projects in a monorepo and wish to treat them as separate process types:

1. Build the projects simultaneously by setting the PROJECT_FILE config var to a solution file that references them.
2. Provide a custom Procfile that enumerates the desired process types, for example:

web: cd $HOME/heroku_output && ./MySolution.Web
worker: cd $HOME/heroku_output && ./MySolution.Worker

ASP.NET Core Demo App

If this project help you, you can give me a cup of coffee ☕