Tighten RemoteDesktop network policies

README.md

@@ -103,6 +103,7 @@ curl -sk -X DELETE https://dns.iamworkin.lan/api/v1/servers/<serverId>/zones/iam
 - **Public read-only hosts**: if a public host fronts a service that also exposes admin writes internally, add a Traefik route match like `Host(...) && (Method(GET) || Method(HEAD))` on the public edge instead of trusting the app to reject unsafe methods.
 - **Public read-write allowlist hosts**: if a public host accepts a tightly bounded write surface (e.g. bootstrap-JWT POST), pin the allowlist as `(Method(GET) || Method(HEAD) || Method(POST) || Method(OPTIONS))`. PUT/PATCH/DELETE must still 404 at the route. Track A's `updatecenter.iamworkin.lan` / `updates.iamworkin.lan` are the canonical example. The lint test enforces this invariant.
 - **Traefik VIP netpols**: when a `NetworkPolicy` allows `10.0.56.200`, also allow the post-DNAT backend ports (`8443` for TLS plus `8080` or `8000` for HTTP) or Calico will drop the rewritten flow.
+- **RemoteDesktop isolation**: `apps/fc-desktop/network-policies.yaml` intentionally keeps desktop pod egress to named CoreDNS, `intranet-web:5300/TCP`, and noc1 step-ca `10.0.56.10:9000/9443` only. Guacamole display egress is owned separately by `apps/guacamole/guacamole.yaml` through `guacd-desktop-egress` on `5901/TCP`.
 - **Auth-safe probes**: services behind API-key or global auth middleware should prefer `tcpSocket` probes unless `/health` is explicitly exempted before the middleware runs.
 - **ArgoCD must use internal Gitea URL**: `http://gitea-clusterip.gitea.svc.cluster.local:3000/bluejay/bluejay-infra.git`, not the external HTTPS URL (step-ca cert isn't trusted by ArgoCD). The `ApplicationSet` and any hand-created `Application` must both use the internal URL.
 

apps/fc-desktop/network-policies.yaml

@@ -20,9 +20,12 @@
 # 1) desktop-isolation — Browser Lab session pods.
 #
 # Locks down pods labeled `app.kubernetes.io/name=remote-desktop` (every
-# session pod regardless of template). Allows guacd ingress for the VNC/RDP
-# display lane and remotedesktop-web's pre-handoff probing. Egress: NFS to
-# Synology, DNS, Traefik (cluster + LB VIP), Intranet (Browser Lab home).
+# session pod regardless of template). Allows guacd ingress for the display
+# lane and remotedesktop-web's pre-handoff probing. Egress is deliberately
+# narrow: named CoreDNS, direct Intranet web, and noc1 step-ca only. There is
+# no broad Traefik/VIP or internet egress from desktop sessions. If a future
+# Browser Lab path needs a public-style host, prefer an explicit Service rule
+# or include the post-DNAT backend port per the Traefik VIP lint.
 apiVersion: networking.k8s.io/v1
 kind: NetworkPolicy
 metadata:
@@ -65,51 +68,22 @@ spec:
         - port: 5901
           protocol: TCP
   egress:
-    # NFS to Synology
+    # CoreDNS only. The old to: [] DNS rule accidentally allowed any DNS
+    # listener in any namespace or routed network.
     - to:
-        - ipBlock:
-            cidr: 10.0.58.3/32
-      ports:
-        - port: 2049
-          protocol: TCP
-        - port: 2049
-          protocol: UDP
-        - port: 111
-          protocol: TCP
-        - port: 111
-          protocol: UDP
-    - to:
-        - ipBlock:
-            cidr: 10.0.58.3/32
-      ports:
-        - port: 445
-          protocol: TCP
-    - to: []
-      ports:
-        - port: 53
-          protocol: UDP
-        - port: 53
-          protocol: TCP
-    - to:
-        - ipBlock:
-            cidr: 10.0.56.200/32
-        - ipBlock:
-            cidr: 10.43.33.87/32
         - namespaceSelector:
             matchLabels:
-              kubernetes.io/metadata.name: traefik-system
+              kubernetes.io/metadata.name: kube-system
           podSelector:
             matchLabels:
-              app.kubernetes.io/name: traefik
+              k8s-app: kube-dns
       ports:
-        - port: 80
-          protocol: TCP
-        - port: 443
-          protocol: TCP
-        - port: 8000
-          protocol: TCP
-        - port: 8443
+        - port: 53
+          protocol: UDP
+        - port: 53
           protocol: TCP
+    # Browser Lab home / internal docs target. Use the real service port
+    # directly rather than public Traefik host aliases.
     - to:
         - namespaceSelector:
             matchLabels:
@@ -120,6 +94,17 @@ spec:
       ports:
         - port: 5300
           protocol: TCP
+    # noc1 step-ca ACME endpoint. The lane brief called out 9000/TCP; the live
+    # ACME directory currently answers on 9443/TCP, so both stay pinned to the
+    # same host rather than reopening Traefik or internet egress.
+    - to:
+        - ipBlock:
+            cidr: 10.0.56.10/32
+      ports:
+        - port: 9000
+          protocol: TCP
+        - port: 9443
+          protocol: TCP
 ---
 # 2) fc-desktop-default-deny — namespace-wide catch-all.
 #
@@ -330,3 +315,11 @@ spec:
           protocol: UDP
         - port: 53
           protocol: TCP
+    - to:
+        - ipBlock:
+            cidr: 10.0.56.10/32
+      ports:
+        - port: 9000
+          protocol: TCP
+        - port: 9443
+          protocol: TCP

apps/guacamole/guacamole.yaml

@@ -254,6 +254,68 @@ spec:
       targetPort: 4822
       name: guacd
 ---
+# Guacd display egress isolation.
+#
+# Guacamole web talks to guacd on TCP/4822. Guacd then opens the desktop
+# display connection to the per-session pod. Keep that second hop at raw VNC
+# 5901/TCP for the current RemoteDesktop Browser Lab/openSUSE images. Do not
+# grant guacd broad fc-desktop namespace egress; desktop-to-desktop lateral
+# paths remain blocked by apps/fc-desktop/network-policies.yaml.
+apiVersion: networking.k8s.io/v1
+kind: NetworkPolicy
+metadata:
+  name: guacd-desktop-egress
+  namespace: guacamole
+  labels:
+    app.kubernetes.io/part-of: remotedesktop
+    app.kubernetes.io/component: display-isolation
+spec:
+  podSelector:
+    matchLabels:
+      app: guacd
+  policyTypes:
+    - Ingress
+    - Egress
+  ingress:
+    - from:
+        - podSelector:
+            matchLabels:
+              app: guacamole
+      ports:
+        - port: 4822
+          protocol: TCP
+  egress:
+    - to:
+        - namespaceSelector:
+            matchLabels:
+              kubernetes.io/metadata.name: kube-system
+          podSelector:
+            matchLabels:
+              k8s-app: kube-dns
+      ports:
+        - port: 53
+          protocol: UDP
+        - port: 53
+          protocol: TCP
+    # kubectl-proxy sidecar reaches the Kubernetes API; keep it explicit
+    # because this NetworkPolicy selects the whole guacd pod.
+    - to: []
+      ports:
+        - port: 443
+          protocol: TCP
+        - port: 6443
+          protocol: TCP
+    - to:
+        - namespaceSelector:
+            matchLabels:
+              kubernetes.io/metadata.name: fc-desktop
+          podSelector:
+            matchLabels:
+              app.kubernetes.io/name: remote-desktop
+      ports:
+        - port: 5901
+          protocol: TCP
+---
 # Guacamole Web Application
 apiVersion: apps/v1
 kind: Deployment

tests/bluejay-infra-lint/RemoteDesktopNetworkPolicyTests.cs

@@ -0,0 +1,93 @@
+using FluentAssertions;
+using Xunit;
+
+namespace BluejayInfraLint.Tests;
+
+[Trait("Category", "Unit")]
+public sealed class RemoteDesktopNetworkPolicyTests
+{
+    private static readonly ManifestInventory Inventory = ManifestInventory.Load();
+
+    [Fact]
+    public void LiveDesktopIsolation_AllowsOnlyCoreDnsIntranetAndStepCaEgress()
+    {
+        var policy = NetworkPolicy("fc-desktop", "desktop-isolation");
+        var ports = policy.EgressPorts().ToHashSet(StringComparer.Ordinal);
+
+        ports.Should().BeEquivalentTo("53", "5300", "9000", "9443");
+        policy.AllScalars().Should().Contain(new[]
+        {
+            "kube-system",
+            "kube-dns",
+            "intranet",
+            "intranet-web",
+            "10.0.56.10/32"
+        });
+    }
+
+    [Fact]
+    public void LiveDesktopIsolation_RemovesInternetNfsAndTraefikEgress()
+    {
+        var policy = NetworkPolicy("fc-desktop", "desktop-isolation");
+        var scalars = policy.AllScalars().ToList();
+        var ports = policy.EgressPorts().ToHashSet(StringComparer.Ordinal);
+
+        scalars.Should().NotContain(new[] { "10.0.58.3/32", "10.0.56.200/32", "10.43.33.87/32", "traefik-system" });
+        ports.Should().NotContain(new[] { "80", "443", "445", "111", "2049", "8000", "8080", "8443" });
+        policy.MappingSequence("spec", "egress")
+            .Should()
+            .NotContain(rule => EgressRuleHasEmptyTo(rule), "desktop sessions must not use to: [] internet-style egress");
+    }
+
+    [Fact]
+    public void LiveGuacdIsolation_AllowsRawVncToDesktopPodsOnly()
+    {
+        var policy = NetworkPolicy("guacamole", "guacd-desktop-egress");
+        var scalars = policy.AllScalars().ToList();
+        var ports = policy.EgressPorts().ToHashSet(StringComparer.Ordinal);
+
+        ports.Should().Contain("5901");
+        scalars.Should().Contain(new[] { "fc-desktop", "remote-desktop" });
+        ports.Should().NotContain(new[] { "3000", "3001", "3389", "80", "8080", "8443" });
+    }
+
+    [Fact]
+    public void LiveGuacdIsolation_KeepsGuacamoleWebIngressOnGuacdPort()
+    {
+        var policy = NetworkPolicy("guacamole", "guacd-desktop-egress");
+
+        policy.Scalar("spec", "podSelector", "matchLabels", "app").Should().Be("guacd");
+        policy.AllScalars().Should().Contain(new[] { "guacamole", "4822" });
+    }
+
+    [Fact]
+    public void HelperSmoke_FindsExpectedRemoteDesktopPolicies()
+    {
+        NetworkPolicy("fc-desktop", "desktop-isolation").Name.Should().Be("desktop-isolation");
+        NetworkPolicy("guacamole", "guacd-desktop-egress").Name.Should().Be("guacd-desktop-egress");
+    }
+
+    [Fact]
+    public void HelperSmoke_EgressPortExtractionKeepsDistinctPorts()
+    {
+        var ports = NetworkPolicy("fc-desktop", "desktop-isolation")
+            .EgressPorts()
+            .ToHashSet(StringComparer.Ordinal);
+
+        ports.Should().HaveCount(4);
+        ports.Should().Contain(new[] { "53", "5300", "9000", "9443" });
+    }
+
+    private static ManifestDocument NetworkPolicy(string ns, string name)
+        => Inventory.Documents.Single(document =>
+            document.Kind == "NetworkPolicy"
+            && string.Equals(document.Namespace, ns, StringComparison.Ordinal)
+            && string.Equals(document.Name, name, StringComparison.Ordinal));
+
+    private static bool EgressRuleHasEmptyTo(YamlDotNet.RepresentationModel.YamlMappingNode rule)
+        => rule.Children.Any(entry =>
+            entry.Key is YamlDotNet.RepresentationModel.YamlScalarNode key
+            && string.Equals(key.Value, "to", StringComparison.Ordinal)
+            && entry.Value is YamlDotNet.RepresentationModel.YamlSequenceNode sequence
+            && sequence.Children.Count == 0);
+}