Fix devcontainer to properly restore projects with private NuGet feed using interactive authentication

[Copilot]

The devcontainer configuration was missing authentication setup for the private Azure DevOps NuGet feed, preventing proper package restoration when using GitHub Codespaces or local devcontainer development.

Problem

The existing devcontainer would fail to restore packages that depend on private NuGet packages from the Azure DevOps feed (https://pkgs.dev.azure.com/intelliTect/_packaging/EssentialCSharp/nuget/v3/index.json). This affected packages like:

• ContentFeedNuget
• EssentialCSharp.Shared.Models

Solution

This PR implements a secure interactive authentication solution using Microsoft's recommended approach for Azure Artifacts Credential Provider:

Key Changes

1. Enhanced devcontainer.json:

   • Updated to use .NET 9.0 SDK specifically
   • Added VS Code C# extensions for better development experience
   • Added post-create command for automated setup
   • Removed hardcoded environment variables for cleaner configuration

2. Interactive Authentication Setup:

   • Created setup-nuget-auth.sh script that:
     • Installs Azure Artifacts Credential Provider automatically
     • Uses dotnet restore --interactive for secure credential prompting
     • Gracefully falls back to public packages only when authentication fails
     • Provides clear user guidance for authentication options

3. Developer Experience:

   • Secure interactive authentication - no need to store PATs in files or environment variables
   • Automatic fallback to public packages when private authentication is unavailable
   • Clear user prompts and guidance during setup
   • Follows Microsoft's recommended authentication patterns

Authentication Options

Interactive Authentication: When prompted during package restoration, users can:

1. Use their Azure DevOps account credentials, or
2. Create a Personal Access Token (PAT) with 'Packaging (read)' permissions from https://dev.azure.com/intelliTect/_usersSettings/tokens

Backward Compatibility

The solution is fully backward compatible:

• Developers without private feed access can still use the devcontainer
• The setup script automatically falls back to public packages when authentication fails
• All public packages restore normally without any user interaction required

Testing

• ✅ Package restoration works without authentication (public packages only)
• ✅ Interactive authentication works for private packages
• ✅ Build and tests pass successfully
• ✅ Graceful handling of network restrictions and missing dependencies
• ✅ Secure credential handling with no storage of sensitive information

This brings the devcontainer authentication in line with Microsoft's recommended security practices while ensuring consistent development environments across local development, Codespaces, and CI/CD pipelines.

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[Copilot]

Pull Request Overview

Fixes devcontainer configuration to enable proper package restoration when using private Azure DevOps NuGet feeds, ensuring developers can work seamlessly in GitHub Codespaces or local devcontainer environments.

• Enhanced devcontainer.json with .NET 9.0 SDK, VS Code C# extensions, and authentication setup
• Added automated NuGet authentication script with Azure DevOps PAT support and graceful fallback
• Created comprehensive documentation and templates for developer onboarding

Reviewed Changes

Copilot reviewed 4 out of 5 changed files in this pull request and generated 2 comments.

File	Description
.devcontainer/setup-nuget-auth.sh	Automated script for installing Azure Artifacts Credential Provider and configuring NuGet authentication
.devcontainer/devcontainer.json	Updated container configuration with .NET 9.0, VS Code extensions, and post-create setup command
.devcontainer/README.md	Comprehensive setup documentation with authentication instructions and troubleshooting guide
.devcontainer/.env.template	Template file for local Azure DevOps PAT configuration

[BenjaminMichaelis]

@copilot Instead of providing the PAT in the repo, should we just run dotnet restore --interactive after installing the cred provider after the container is built and the user can input it? https://github.com/Microsoft/artifacts-credprovider

[Copilot]

@copilot Instead of providing the PAT in the repo, should we just run dotnet restore --interactive after installing the cred provider after the container is built and the user can input it? https://...

You're absolutely right! The interactive approach is more secure and simpler. I'll update the setup to install the credential provider and use dotnet restore --interactive instead of requiring PAT storage in environment variables.