Tailscale ACL: admit tag:dashboard to the dusk-1 serving API (tcp:8080)

dag/extdeps/tailscale/acl.dag

@@ -38,6 +38,12 @@ data tag_dashboard: NonEmptyStr = "tag:dashboard"
 data dashboard_tcp_port: NonEmptyStr = "tcp:3737"
 data ssh_tcp_port: NonEmptyStr = "tcp:22"
 
+// dusk-1 is the operator's desktop (WSL) serving an OpenAI-compatible inference API while the
+// Sparks are sold. It is an untagged member device, so no tag grant reaches it; this admits only
+// the dashboard plane to its API port. tag:ci stays quarantined to the dashboard port.
+data dusk_serving_ip: NonEmptyStr = "100.127.39.77"
+data dusk_serving_api_tcp_port: NonEmptyStr = "tcp:8080"
+
 type TailscaleAclSelector
   = AclTag { label: NonEmptyStr }
   | AclAutogroup { group: NonEmptyStr }
@@ -158,12 +164,21 @@ fn tag_dashboard_to_ci_ssh_grant() -> TailscaleGrant {
   }
 }
 
+fn tag_dashboard_to_dusk_serving_api_grant() -> TailscaleGrant {
+  TailscaleGrant {
+    src: [sel_tag_dashboard()],
+    dst: [sel_ipv4(address: dusk_serving_ip)],
+    ip: [sel_proto_port(spec: dusk_serving_api_tcp_port)],
+  }
+}
+
 fn operator_tailscale_acl_grants() -> List<TailscaleGrant> {
   [
     member_baseline_grant(),
     tag_ci_quarantine_grant(),
     tag_dashboard_self_grant(),
     tag_dashboard_to_ci_ssh_grant(),
+    tag_dashboard_to_dusk_serving_api_grant(),
   ]
 }
 
@@ -304,10 +319,27 @@ fn ssh_dashboard_reaches_ci_root_and_nonroot(policy: TailscaleAclPolicy) -> Bool
   )
 }
 
+fn grant_reaches_dusk_serving(g: TailscaleGrant) -> Bool {
+  selector_list_contains(items: g.dst, needle: sel_ipv4(address: dusk_serving_ip))
+}
+
+fn dusk_serving_reached_by_dashboard_api_only(policy: TailscaleAclPolicy) -> Bool {
+  let tagged = policy.grants |> filter(g => grant_reaches_dusk_serving(g: g))
+  match first(tagged) {
+    Present { value: g } =>
+      (length(tagged) == 1)
+        && (g.src == [sel_tag_dashboard()])
+        && (length(g.dst) == 1)
+        && (g.ip == [sel_proto_port(spec: dusk_serving_api_tcp_port)])
+    Absent => false
+  }
+}
+
 fn operator_acl_security_spine_holds(policy: TailscaleAclPolicy) -> Bool {
   tag_ci_quarantine_holds(policy: policy)
     && tag_dashboard_admin_plane_holds(policy: policy)
     && dashboard_cutover_ip_is_transient_in_tag_ci_grant(policy: policy)
     && ssh_members_reach_ci_nonroot_only(policy: policy)
     && ssh_dashboard_reaches_ci_root_and_nonroot(policy: policy)
+    && dusk_serving_reached_by_dashboard_api_only(policy: policy)
 }

dag/test/claim/tailscale_acl_witness_test.dag

@@ -7,7 +7,7 @@ data tailscale_acl_reference_fixture_path: String = "dag/test/fixture/tailscale_
 
 fn witness_operator_policy_row_counts() -> Bool {
   let policy = operator_tailscale_acl_policy
-  (length(policy.grants) == 4)
+  (length(policy.grants) == 5)
     && (length(policy.ssh) == 3)
     && (length(policy.node_attrs) == 1)
     && (length(policy.tag_owners) == 2)
@@ -43,6 +43,21 @@ fn witness_emit_matches_reference_fixture() -> Bool {
   read.success && (expected_tailscale_acl_json() == read.content)
 }
 
+fn witness_dusk_serving_api_only() -> Bool {
+  let wider = TailscaleAclPolicy {
+    grants: operator_tailscale_acl_policy.grants.append(TailscaleGrant {
+      src: [sel_tag_ci()],
+      dst: [sel_ipv4(address: dusk_serving_ip)],
+      ip: [sel_wildcard()],
+    }),
+    ssh: operator_tailscale_acl_policy.ssh,
+    node_attrs: operator_tailscale_acl_policy.node_attrs,
+    tag_owners: operator_tailscale_acl_policy.tag_owners,
+  }
+  dusk_serving_reached_by_dashboard_api_only(policy: operator_tailscale_acl_policy)
+    && !dusk_serving_reached_by_dashboard_api_only(policy: wider)
+}
+
 fn witness_dashboard_tag_not_ci_in_acl_model() -> Bool {
   tag_dashboard != tag_ci
     && !string_contains(s: tag_dashboard, pattern: "tag:ci")
@@ -58,4 +73,5 @@ test fn tailscale_acl_witnesses() -> Bool {
     && witness_security_spine()
     && witness_emit_matches_reference_fixture()
     && witness_dashboard_tag_not_ci_in_acl_model()
+    && witness_dusk_serving_api_only()
 }

dag/test/fixture/tailscale_acl_reference.json

@@ -1 +1 @@
-{"grants": [{"src": ["autogroup:member"], "dst": ["*"], "ip": ["*"]}, {"src": ["tag:ci"], "dst": ["100.65.94.55", "tag:dashboard"], "ip": ["tcp:3737"]}, {"src": ["tag:dashboard"], "dst": ["tag:dashboard"], "ip": ["*"]}, {"src": ["tag:dashboard"], "dst": ["tag:ci"], "ip": ["tcp:22"]}], "ssh": [{"action": "accept", "src": ["autogroup:member"], "dst": ["autogroup:self"], "users": ["autogroup:nonroot", "root"]}, {"action": "accept", "src": ["autogroup:member"], "dst": ["tag:ci"], "users": ["autogroup:nonroot"]}, {"action": "accept", "src": ["tag:dashboard"], "dst": ["tag:ci"], "users": ["autogroup:nonroot", "root"]}], "nodeAttrs": [{"target": ["autogroup:member"], "attr": ["funnel"]}], "tagOwners": {"tag:ci": ["autogroup:admin"], "tag:dashboard": ["autogroup:admin"]}}
+{"grants": [{"src": ["autogroup:member"], "dst": ["*"], "ip": ["*"]}, {"src": ["tag:ci"], "dst": ["100.65.94.55", "tag:dashboard"], "ip": ["tcp:3737"]}, {"src": ["tag:dashboard"], "dst": ["tag:dashboard"], "ip": ["*"]}, {"src": ["tag:dashboard"], "dst": ["tag:ci"], "ip": ["tcp:22"]}, {"src": ["tag:dashboard"], "dst": ["100.127.39.77"], "ip": ["tcp:8080"]}], "ssh": [{"action": "accept", "src": ["autogroup:member"], "dst": ["autogroup:self"], "users": ["autogroup:nonroot", "root"]}, {"action": "accept", "src": ["autogroup:member"], "dst": ["tag:ci"], "users": ["autogroup:nonroot"]}, {"action": "accept", "src": ["tag:dashboard"], "dst": ["tag:ci"], "users": ["autogroup:nonroot", "root"]}], "nodeAttrs": [{"target": ["autogroup:member"], "attr": ["funnel"]}], "tagOwners": {"tag:ci": ["autogroup:admin"], "tag:dashboard": ["autogroup:admin"]}}