Docker Compose publisher is emitting unusable HTTPS service discovery environment variables.

[mitchdenny]

When using aspire build -p docker-compose the following Docker Compose YAML will be generated:

services:
  apiservice:
    image: "${APISERVICE_IMAGE}"
    environment:
      OTEL_DOTNET_EXPERIMENTAL_OTLP_EMIT_EXCEPTION_LOG_ATTRIBUTES: "true"
      OTEL_DOTNET_EXPERIMENTAL_OTLP_EMIT_EVENT_LOG_ATTRIBUTES: "true"
      OTEL_DOTNET_EXPERIMENTAL_OTLP_RETRY: "in_memory"
      ASPNETCORE_FORWARDEDHEADERS_ENABLED: "true"
      HTTP_PORTS: "8000"
    ports:
      - "8001:8000"
      - "8003:8002"
    networks:
      - "aspire"
  webfrontend:
    image: "${WEBFRONTEND_IMAGE}"
    environment:
      OTEL_DOTNET_EXPERIMENTAL_OTLP_EMIT_EXCEPTION_LOG_ATTRIBUTES: "true"
      OTEL_DOTNET_EXPERIMENTAL_OTLP_EMIT_EVENT_LOG_ATTRIBUTES: "true"
      OTEL_DOTNET_EXPERIMENTAL_OTLP_RETRY: "in_memory"
      ASPNETCORE_FORWARDEDHEADERS_ENABLED: "true"
      HTTP_PORTS: "8004"
      services__apiservice__http__0: "http://apiservice:8000"
      services__apiservice__https__0: "https://apiservice:8002"
    ports:
      - "8005:8004"
      - "8007:8006"
    networks:
      - "aspire"
networks:
  aspire:
    driver: "bridge"

This is the YAML file generated from the template, and hitting the weather endpoint on the front end doesn't work because the template is configured to preference the HTTPS connection. Unfortunately, in Docker Compose we don't do any TLS setup.

There are a couple of things we could do here:

1. Modify the Docker Compose publisher to automatically exclude TLS endpoints.
2. Give developers instructions to fine-tune their code for publish scenarios (see example):

using Aspire.Hosting.Docker;

var builder = DistributedApplication.CreateBuilder(args);

builder.AddDockerComposePublisher();

var apiService = builder.AddProject<Projects.HelloAspire_ApiService>("apiservice");

builder.AddProject<Projects.HelloAspire_Web>("webfrontend")
    .WithExternalHttpEndpoints()
    .WithReference(apiService.GetEndpoint("http")) // Only reference HTTP.
    .WaitFor(apiService);

builder.Build().Run();

[mitchdenny]

@davidfowl @prom3theu5 what do you think about forcing people to WithReference(api.GetEndpoint(...)) to limit the endpoints that are emitted into Docker Compose vs. the compose publisher filtering HTTPS automatically.

Initially I was leaning doing something in the publisher, but I am not sure that is the right thing to do now. We should lean into people declaring what they want in the app host?

[prom3theu5]

@davidfowl @prom3theu5 what do you think about forcing people to WithReference(api.GetEndpoint(...)) to limit the endpoints that are emitted into Docker Compose vs. the compose publisher filtering HTTPS automatically.

Initially I was leaning doing something in the publisher, but I am not sure that is the right thing to do now. We should lean into people declaring what they want in the app host?

I agree. I think that’s the best way to think about it :)
Purely as declarative as possible, and less automagically lol