wireguard-go/flake.nix

{
  description = "WireGuard Go development environment";

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
    flake-utils.url = "github:numtide/flake-utils";
  };

  outputs = { self, nixpkgs, flake-utils }:
    flake-utils.lib.eachDefaultSystem (system:
      let
        pkgs = nixpkgs.legacyPackages.${system};
        
        # Go version matching go.mod
        go = pkgs.go_1_23;
        
        # Additional Go tools for development
        goTools = with pkgs; [
          # Core Go toolchain
          go
          
          # Language Server Protocol
          gopls
          
          # Formatting and imports
          gofmt
          goimports
          gofumpt  # Stricter gofmt
          
          # Linting and static analysis
          golangci-lint
          staticcheck
          gosec      # Security checker
          ineffassign
          misspell
          
          # Debugging
          delve
          
          # Code generation and refactoring
          gotests       # Generate tests
          gomodifytags  # Modify struct tags
          impl          # Generate interface implementations
          govulncheck   # Vulnerability scanner
          
          # Build and development tools
          air           # Live reload
          gotools       # Various tools (guru, gorename, etc.)
          
          # Testing and benchmarking
          gotestsum     # Pretty test output
          
          # Documentation
          godoc
        ];
        
        # System tools
        systemTools = with pkgs; [
          git
          make
          direnv
          nix-direnv
          
          # Networking tools (useful for WireGuard development)
          iproute2
          iptables
          wireguard-tools
          
          # Text processing
          jq
          yq-go
          
          # Shell and utilities
          fish
          ripgrep
          fd
          tree
        ];

      in
      {
        devShells.default = pkgs.mkShell {
          buildInputs = goTools ++ systemTools;
          
          shellHook = ''
            echo "🚀 WireGuard Go development environment loaded!"
            echo "📦 Go version: $(go version)"
            echo "🔧 Available tools:"
            echo "  • LSP: gopls"
            echo "  • Linting: golangci-lint, staticcheck, gosec"
            echo "  • Formatting: gofmt, goimports, gofumpt"
            echo "  • Debugging: delve (dlv)"
            echo "  • Testing: gotests, gotestsum"
            echo "  • Security: govulncheck"
            echo "  • Live reload: air"
            echo ""
            echo "💡 Quick commands:"
            echo "  • go mod tidy          # Clean dependencies"
            echo "  • golangci-lint run    # Run all linters"
            echo "  • govulncheck ./...    # Check for vulnerabilities"
            echo "  • gotests -all         # Generate tests"
            echo "  • air                  # Live reload server"
            echo ""
            
            # Set up Go environment
            export GOPATH="$PWD/.go"
            export GOBIN="$GOPATH/bin"
            export PATH="$GOBIN:$PATH"
            
            # Create necessary directories
            mkdir -p "$GOPATH/bin"
            
            # Set Go build cache to project directory
            export GOCACHE="$PWD/.gocache"
            mkdir -p "$GOCACHE"
            
            # Ensure proper Go module mode
            export GO111MODULE=on
            
            # Development-friendly settings
            export GOTOOLCHAIN="go1.23.1"
            export CGO_ENABLED=1
            
            # WireGuard specific
            export WG_COLOR_MODE=always
          '';
          
          # Environment variables for tools
          CGO_ENABLED = "1";
          GO111MODULE = "on";
          GOFLAGS = "-buildvcs=false";  # Disable VCS stamping for reproducible builds
        };
        
        # Optional: Create a package for the WireGuard binary
        packages.default = pkgs.buildGoModule {
          pname = "wireguard-go";
          version = "0.0.0-dev";
          src = ./.;
          vendorHash = null;  # Let Nix handle dependencies
          
          meta = with pkgs.lib; {
            description = "Userspace Go implementation of WireGuard";
            homepage = "https://www.wireguard.com/";
            license = licenses.mit;
            platforms = platforms.linux ++ platforms.darwin;
          };
        };
      });
}