Add comprehensive debug output for GHA network state and VM networking

Author: Lillecarl

.github/workflows/test-nixos.yaml

@@ -38,9 +38,67 @@ jobs:
           echo "${{ secrets.NIXBUILD_KEY }}" | install -D -m 600 /dev/stdin ~/.ssh/nixbuild_key
           install -m 644 "${{ github.workspace }}/.github/assets/ssh-config" ~/.ssh/config
 
+      - name: Debug - GHA runner network state (before)
+        shell: bash
+        run: |
+          echo "=== IP Addresses ==="
+          ip addr
+          echo ""
+          echo "=== Routing Table ==="
+          ip route
+          echo ""
+          echo "=== Network Interfaces ==="
+          ip link
+          echo ""
+          echo "=== Iptables Rules (filter) ==="
+          sudo iptables -L -v
+          echo ""
+          echo "=== Iptables Rules (nat) ==="
+          sudo iptables -t nat -L -v
+          echo ""
+          echo "=== Iptables Rules (mangle) ==="
+          sudo iptables -t mangle -L -v
+          echo ""
+          echo "=== Netstat listening ports ==="
+          sudo ss -tlnp || netstat -tlnp || echo "ss/netstat not available"
+          echo ""
+          echo "=== Kernel IP forwarding ==="
+          cat /proc/sys/net/ipv4/ip_forward
+
       - name: Run nixos test
         run: nix run --file . nixosNatTest.containerd.driverInteractive --option sandbox false -- --no-interactive
 
+      - name: Debug - GHA runner network state (after)
+        if: failure()
+        shell: bash
+        run: |
+          echo "=== IP Addresses ==="
+          ip addr
+          echo ""
+          echo "=== Routing Table ==="
+          ip route
+          echo ""
+          echo "=== Network Interfaces ==="
+          ip link
+          echo ""
+          echo "=== Iptables Rules (filter) ==="
+          sudo iptables -L -v
+          echo ""
+          echo "=== Iptables Rules (nat) ==="
+          sudo iptables -t nat -L -v
+          echo ""
+          echo "=== Iptables Rules (mangle) ==="
+          sudo iptables -t mangle -L -v
+          echo ""
+          echo "=== Check for vde interfaces ==="
+          ip link | grep -i vde || echo "No vde interfaces found"
+          echo ""
+          echo "=== Kernel IP forwarding ==="
+          cat /proc/sys/net/ipv4/ip_forward
+          echo ""
+          echo "=== Dmesg last 50 lines ==="
+          sudo dmesg | tail -50
+
       - name: Setup upterm session
         if: failure()
         uses: owenthereal/action-upterm@v1

tests/nixos/integration.nix

@@ -48,10 +48,23 @@ pkgs.testers.nixosTest {
     # Debug: Check if networking is available
     with control.nested("check networking"):
         control.wait_for_unit("network-online.target", timeout=30)
-        control.succeed("ping -c 1 1.1.1.1 || ping -c 1 9.9.9.9 || echo 'WARNING: No external ping response'")
+
+        # Capture VM network state
+        control.succeed("echo '=== IP Addresses ===' && ip addr")
+        control.succeed("echo '=== Routing Table ===' && ip route")
+        control.succeed("echo '=== Default Route ===' && ip route | grep default")
+        control.succeed("echo '=== Kernel IP Forwarding ===' && cat /proc/sys/net/ipv4/ip_forward")
+
+        # Capture DNS state
         control.succeed("cat /etc/resolv.conf || echo 'No resolv.conf'")
         control.succeed("systemctl status systemd-resolved || echo 'systemd-resolved not active'")
 
+        # Try DNS resolution before ping
+        control.succeed("echo '=== Testing DNS ===' && nslookup google.com || dig google.com || echo 'DNS lookup failed'")
+
+        # Try pings
+        control.succeed("ping -c 1 1.1.1.1 || ping -c 1 9.9.9.9 || echo 'WARNING: No external ping response'")
+
     control.wait_for_unit("containerd.service")
 
     # ── Phase 1: Bootstrap kubeadm cluster ──────────────────────────────