Internet and Networking Limitations: Build-Time Access, Container DNS, and GUI Support

[YGLemon]

Problem Description

While using Apple Container for building and running Linux containers, we encountered several limitations that significantly impact usability and flexibility:

1. Lack of GUI support
   • The current container environment does not support running GUI applications directly.
   • Users must rely on VNC, X11 forwarding, or other workarounds to access graphical interfaces, which increases setup complexity and limits the use of containers in research, education, and development environments.
   • Restrictions on build-time network further reduce the convenience of using alternative GUI solutions.
2. Build-time network restrictions
   • During container build, BuildKit seems running in complete isolation and cannot access the internet.
   • Installing system packages or desktop environments through a Dockerfile (apt-get install ...) fails unless offline packages or pre-built images are used, reducing flexibility and slowing down development.
3. Container runtime DNS issues
   • Containers launched from official Linux images (e.g., Ubuntu or Debian from Docker Hub) cannot resolve DNS by default.
   • Commands like apt-get update fail unless /etc/resolv.conf is manually configured.
   • This behavior does not occur in Docker Desktop or WSL environments and introduces obstacles for automated workflows.

Desired Improvements

1. Enable GUI support within containers

   • Allow running GUI applications natively or via macOS-compatible forwarding.
   • This would simplify visualization workflows.

2. Allow build-time internet access

   • Provide functionality similar to Docker's --network=host, allowing Dockerfile commands to access external networks.
   • This enables flexible installation of packages and building complex images without relying on offline artifacts.

3. Fix container runtime DNS issues

   • Ensure containers launched from official Linux images can resolve DNS and access the internet without manual /etc/resolv.conf modification.
   • Improves reliability for automated builds and standard deployments.

Environment

• Apple Container version: v4.0.1
• macOS version: macOS 26.0.1
• Example image: ubuntu:18.04