by jincod


Heroku .NET Core Buildpack

This is the Heroku buildpack for ASP.NET Core.

Actions Status

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.


.NET Core latest stable

heroku buildpacks:set jincod/dotnetcore

.NET Core edge

heroku buildpacks:set

.NET Core Preview release

heroku buildpacks:set

Previous releases

heroku buildpacks:set

Available releases

More info

Entity Framework Core Migrations

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

Enabling Automatic Migrations

  • 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" />

Manually Running Migration Scripts on the Database

  • 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.

Setting Connection String for heroku PostgreSQL

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

Node.js and NPM

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

Using Multiple Buildpacks for an App

herokuish support

heroku config:set HEROKUISH=true


ASP.NET Core Demo App


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