92b39fc031
Host-only 10.99.0.0/24 bridge with no uplink/NAT; firewall drops VM traffic leaving the bridge so unikernel VMs can reach only the gateway (mc-proxy). Implements Phase 2 mandatory-mediation networking. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
65 lines
2.6 KiB
Nix
65 lines
2.6 KiB
Nix
{ inputs, pkgs, lib, ... }:
|
|
{
|
|
imports = [
|
|
./hardware-configuration.nix
|
|
../../configs/desktop.nix
|
|
../../configs/qemu.nix
|
|
../../configs/mcpkg.nix
|
|
../../configs/mcp.nix # MCP agent + mcp user (straylight is becoming the core host)
|
|
];
|
|
|
|
config = {
|
|
# straylight is the unikernel host. The shared mcp.nix locks the agent
|
|
# down with PrivateDevices=true, which hides /dev/kvm and /dev/net/tun.
|
|
# Relax that here (only on straylight) so the agent can boot Nanos
|
|
# unikernel VMs under QEMU/KVM and (Phase 2) manage TAP devices.
|
|
systemd.services.mcp-agent.serviceConfig = {
|
|
PrivateDevices = lib.mkForce false;
|
|
DeviceAllow = [ "/dev/kvm rw" "/dev/net/tun rw" ];
|
|
SupplementaryGroups = [ "kvm" ];
|
|
AmbientCapabilities = [ "CAP_NET_ADMIN" ];
|
|
};
|
|
# Let the mcp user reach /dev/kvm directly as well.
|
|
users.users.mcp.extraGroups = [ "kvm" ];
|
|
|
|
# Isolated host-only bridge for unikernel VMs (Phase 2). Each unikernel
|
|
# gets a TAP on this bridge and a 10.99.0.0/24 static IP. The bridge has
|
|
# NO uplink and NO NAT, and the firewall drops any VM traffic leaving the
|
|
# bridge, so a VM can reach only the host gateway (10.99.0.1) -- mediation
|
|
# is enforced by network topology, not convention.
|
|
networking.bridges.mcp-br0.interfaces = [ ];
|
|
networking.interfaces.mcp-br0.ipv4.addresses = [
|
|
{ address = "10.99.0.1"; prefixLength = 24; }
|
|
];
|
|
# The host accepts traffic from VMs (so mc-proxy on the gateway can serve
|
|
# them); the FORWARD drop prevents VMs from routing anywhere off-bridge.
|
|
networking.firewall.trustedInterfaces = [ "mcp-br0" ];
|
|
networking.firewall.extraCommands = ''
|
|
iptables -D FORWARD -i mcp-br0 ! -o mcp-br0 -j DROP 2>/dev/null || true
|
|
iptables -A FORWARD -i mcp-br0 ! -o mcp-br0 -j DROP
|
|
'';
|
|
networking.firewall.extraStopCommands = ''
|
|
iptables -D FORWARD -i mcp-br0 ! -o mcp-br0 -j DROP 2>/dev/null || true
|
|
'';
|
|
|
|
# Allow rootless containers (podman) to bind low ports (53 for MCNS,
|
|
# 443/8443/9443 for mc-proxy) as straylight takes over the core role.
|
|
boot.kernel.sysctl."net.ipv4.ip_unprivileged_port_start" = 53;
|
|
|
|
# Open ports: DNS (53), mc-proxy (443/8443/9443), agent (9444), master (9555).
|
|
networking.firewall.allowedTCPPorts = [ 53 443 8443 9443 9444 9555 ];
|
|
networking.firewall.allowedUDPPorts = [ 53 ];
|
|
|
|
# DNS: MCNS for internal zones, public resolvers as fallback.
|
|
networking.nameservers = [
|
|
"192.168.88.181"
|
|
"100.95.252.120"
|
|
"1.1.1.1"
|
|
"8.8.8.8"
|
|
];
|
|
services.resolved.domains = [
|
|
"~mcp.metacircular.net"
|
|
];
|
|
};
|
|
}
|