Hosting ASP.NET Core images with Docker Compose over HTTPS

ASP.NET Core uses HTTPS by default. HTTPS relies on certificates for trust, identity, and encryption.

This document explains how to run pre-built container images with HTTPS.

See Developing ASP.NET Core Applications with Docker over HTTPS for development scenarios.

This sample requires Docker 17.06 or later of the Docker client.

Prerequisites

The .NET Core 2.2 SDK or later is required for some of the instructions in this document.

Certificates

A certificate from a certificate authority is required for production hosting for a domain. Let's Encrypt is a certificate authority that offers free certificates.

This document uses self-signed development certificates for hosting pre-built images over localhost. The instructions are similar to using production certificates.

For production certificates:

  • The dotnet dev-certs tool is not required.
  • Certificates don't need to be stored in the location used in the instructions. Store the certificates in any location outside the site directory.

The instructions contained in the following section volume mount certificates into containers using the volumes property in docker-compose.yml. You could add certificates into container images with a COPY command in a Dockerfile, but it's not recommended. Copying certificates into an image isn't recommended for the following reasons:

  • It makes it difficult to use the same image for testing with developer certificates.
  • It makes it difficult to use the same image for Hosting with production certificates.
  • There is significant risk of certificate disclosure.

Starting a container with https support using docker compose

Use the following instructions for your operating system configuration.

Windows using Linux containers

Generate certificate and configure local machine:

dotnet dev-certs https -ep %USERPROFILE%\.aspnet\https\aspnetapp.pfx -p { password here }
dotnet dev-certs https --trust

In the preceding commands, replace { password here } with a password.

Create a docker-compose.debug.yml file with the following content:

version: '3.4'

services:
  webapp:
    image: mcr.microsoft.com/dotnet/core/samples:aspnetapp
    ports:
      - 80
      - 443
    environment:
      - ASPNETCORE_ENVIRONMENT=Development
      - ASPNETCORE_URLS=https://+:443;http://+:80
      - ASPNETCORE_Kestrel__Certificates__Default__Password=password
      - ASPNETCORE_Kestrel__Certificates__Default__Path=/https/aspnetapp.pfx
    volumes:
      - ~/.aspnet/https:/https:ro

The password specified in the docker compose file must match the password used for the certificate.

Start the container with ASP.NET Core configured for HTTPS:

docker-compose -f "docker-compose.debug.yml" up -d

macOS or Linux

Generate certificate and configure local machine:

dotnet dev-certs https -ep ${HOME}/.aspnet/https/aspnetapp.pfx -p { password here }
dotnet dev-certs https --trust

dotnet dev-certs https --trust is only supported on macOS and Windows. You need to trust certificates on Linux in the way that is supported by your distribution. It is likely that you need to trust the certificate in your browser.

In the preceding commands, replace { password here } with a password.

Create a docker-compose.debug.yml file with the following content:

version: '3.4'

services:
  webapp:
    image: mcr.microsoft.com/dotnet/core/samples:aspnetapp
    ports:
      - 80
      - 443
    environment:
      - ASPNETCORE_ENVIRONMENT=Development
      - ASPNETCORE_URLS=https://+:443;http://+:80
      - ASPNETCORE_Kestrel__Certificates__Default__Password=password
      - ASPNETCORE_Kestrel__Certificates__Default__Path=/https/aspnetapp.pfx
    volumes:
      - ~/.aspnet/https:/https:ro

The password specified in the docker compose file must match the password used for the certificate.

Start the container with ASP.NET Core configured for HTTPS:

docker-compose -f "docker-compose.debug.yml" up -d

Windows using Windows containers

Generate certificate and configure local machine:

dotnet dev-certs https -ep %USERPROFILE%\.aspnet\https\aspnetapp.pfx -p { password here }
dotnet dev-certs https --trust

In the preceding commands, replace { password here } with a password.

Create a docker-compose.debug.yml file with the following content:

version: '3.4'

services:
  webapp:
    image: mcr.microsoft.com/dotnet/core/samples:aspnetapp
    ports:
      - 80
      - 443
    environment:
      - ASPNETCORE_ENVIRONMENT=Development
      - ASPNETCORE_URLS=https://+:443;http://+:80
      - ASPNETCORE_Kestrel__Certificates__Default__Password=password
      - ASPNETCORE_Kestrel__Certificates__Default__Path=C:\https\aspnetapp.pfx
    volumes:
      - ${USERPROFILE}\.aspnet\https:C:\https:ro

The password specified in the docker compose file must match the password used for the certificate.

Start the container with ASP.NET Core configured for HTTPS:

docker-compose -f "docker-compose.debug.yml" up -d