consul: break acl filtering into a separate struct

consul/acl.go

@@ -2,6 +2,7 @@ package consul
 
 import (
 	"errors"
+	"log"
 	"strings"
 	"time"
 
@@ -193,10 +194,125 @@ func (s *Server) useACLPolicy(id, authDC string, cached *aclCacheEntry, p *struc
 	return compiled, nil
 }
 
-// applyDiscoveryACLs is used to filter results from our service catalog based
-// on the configured rules for the request ACL. Nodes or services which do
-// not match the ACL rules will be dropped from the result.
-func (s *Server) applyDiscoveryACLs(token string, subj interface{}) error {
+// aclFilter is used to filter results from our state store based on ACL rules
+// configured for the provided token.
+type aclFilter struct {
+	acl    acl.ACL
+	logger *log.Logger
+}
+
+// filterService is used to determine if a service is accessible for an ACL.
+func (f *aclFilter) filterService(service string) bool {
+	if service == "" || service == ConsulServiceID {
+		return true
+	}
+	return f.acl.ServiceRead(service)
+}
+
+// filterHealthChecks is used to filter a set of health checks down based on
+// the configured ACL rules for a token.
+func (f *aclFilter) filterHealthChecks(checks *structs.HealthChecks) {
+	hc := *checks
+	for i := 0; i < len(hc); i++ {
+		check := hc[i]
+		if f.filterService(check.ServiceName) {
+			continue
+		}
+		f.logger.Printf("[DEBUG] consul: dropping check %q from result due to ACLs", check.CheckID)
+		hc = append(hc[:i], hc[i+1:]...)
+		i--
+	}
+	*checks = hc
+}
+
+// filterServices is used to filter a set of services based on ACLs.
+func (f *aclFilter) filterServices(services structs.Services) {
+	for svc, _ := range services {
+		if f.filterService(svc) {
+			continue
+		}
+		f.logger.Printf("[DEBUG] consul: dropping service %q from result due to ACLs", svc)
+		delete(services, svc)
+	}
+}
+
+// filterServiceNodes is used to filter a set of nodes for a given service
+// based on the configured ACL rules.
+func (f *aclFilter) filterServiceNodes(nodes *structs.ServiceNodes) {
+	sn := *nodes
+	for i := 0; i < len(sn); i++ {
+		node := sn[i]
+		if f.filterService(node.ServiceName) {
+			continue
+		}
+		f.logger.Printf("[DEBUG] consul: dropping node %q from result due to ACLs", node.Node)
+		sn = append(sn[:i], sn[i+1:]...)
+		i--
+	}
+	*nodes = sn
+}
+
+// filterNodeServices is used to filter services on a given node base on ACLs.
+func (f *aclFilter) filterNodeServices(services *structs.NodeServices) {
+	for svc, _ := range services.Services {
+		if f.filterService(svc) {
+			continue
+		}
+		f.logger.Printf("[DEBUG] consul: dropping service %q from result due to ACLs", svc)
+		delete(services.Services, svc)
+	}
+}
+
+// filterCheckServiceNodes is used to filter nodes based on ACL rules.
+func (f *aclFilter) filterCheckServiceNodes(nodes *structs.CheckServiceNodes) {
+	csn := *nodes
+	for i := 0; i < len(csn); i++ {
+		node := csn[i]
+		if f.filterService(node.Service.Service) {
+			continue
+		}
+		f.logger.Printf("[DEBUG] consul: dropping node %q from result due to ACLs", node.Node)
+		csn = append(csn[:i], csn[i+1:]...)
+		i--
+	}
+	*nodes = csn
+}
+
+// filterNodeDump is used to filter through all parts of a node dump and
+// remove elements the provided ACL token cannot access.
+func (f *aclFilter) filterNodeDump(dump *structs.NodeDump) {
+	nd := *dump
+	for i := 0; i < len(nd); i++ {
+		info := nd[i]
+
+		// Filter services
+		for i := 0; i < len(info.Services); i++ {
+			svc := info.Services[i].Service
+			if f.filterService(svc) {
+				continue
+			}
+			f.logger.Printf("[DEBUG] consul: dropping service %q from result due to ACLs", svc)
+			info.Services = append(info.Services[:i], info.Services[i+1:]...)
+			i--
+		}
+
+		// Filter checks
+		for i := 0; i < len(info.Checks); i++ {
+			chk := info.Checks[i]
+			if f.filterService(chk.ServiceName) {
+				continue
+			}
+			f.logger.Printf("[DEBUG] consul: dropping check %q from result due to ACLs", chk.CheckID)
+			info.Checks = append(info.Checks[:i], info.Checks[i+1:]...)
+			i--
+		}
+	}
+}
+
+// aclFilter is used to filter results from our service catalog based on the
+// rules configured for the provided token. The subject is scrubbed and
+// modified in-place, leaving only resources the token can access.
+func (s *Server) aclFilter(token string, subj interface{}) error {
 	// Get the ACL from the token
 	acl, err := s.resolveToken(token)
 	if err != nil {
@@ -208,97 +324,27 @@ func (s *Server) applyDiscoveryACLs(token string, subj interface{}) error {
 		return nil
 	}
 
-	filt := func(service string) bool {
-		// Don't filter the "consul" service or empty service names
-		if service == "" || service == ConsulServiceID {
-			return true
-		}
-
-		// Check the ACL
-		if !acl.ServiceRead(service) {
-			s.logger.Printf("[DEBUG] consul: reading service '%s' denied due to ACLs", service)
-			return false
-		}
-		return true
-	}
+	// Create the filter
+	filt := &aclFilter{acl, s.logger}
 
 	switch v := subj.(type) {
-	// Filter health checks
 	case *structs.IndexedHealthChecks:
-		for i := 0; i < len(v.HealthChecks); i++ {
-			hc := v.HealthChecks[i]
-			if filt(hc.ServiceName) {
-				continue
-			}
-			v.HealthChecks = append(v.HealthChecks[:i], v.HealthChecks[i+1:]...)
-			i--
-		}
+		filt.filterHealthChecks(&v.HealthChecks)
 
-	// Filter services
 	case *structs.IndexedServices:
-		for svc, _ := range v.Services {
-			if filt(svc) {
-				continue
-			}
-			delete(v.Services, svc)
-		}
+		filt.filterServices(v.Services)
 
-	// Filter service nodes
 	case *structs.IndexedServiceNodes:
-		for i := 0; i < len(v.ServiceNodes); i++ {
-			node := v.ServiceNodes[i]
-			if filt(node.ServiceName) {
-				continue
-			}
-			v.ServiceNodes = append(v.ServiceNodes[:i], v.ServiceNodes[i+1:]...)
-			i--
-		}
+		filt.filterServiceNodes(&v.ServiceNodes)
 
-	// Filter node services
 	case *structs.IndexedNodeServices:
-		for svc, _ := range v.NodeServices.Services {
-			if filt(svc) {
-				continue
-			}
-			delete(v.NodeServices.Services, svc)
-		}
+		filt.filterNodeServices(v.NodeServices)
 
-	// Filter check service nodes
 	case *structs.IndexedCheckServiceNodes:
-		for i := 0; i < len(v.Nodes); i++ {
-			cs := v.Nodes[i]
-			if filt(cs.Service.Service) {
-				continue
-			}
-			v.Nodes = append(v.Nodes[:i], v.Nodes[i+1:]...)
-			i--
-		}
+		filt.filterCheckServiceNodes(&v.Nodes)
 
-	// Filter node dumps
 	case *structs.IndexedNodeDump:
-		for i := 0; i < len(v.Dump); i++ {
-			dump := v.Dump[i]
-
-			// Filter the services
-			for i := 0; i < len(dump.Services); i++ {
-				svc := dump.Services[i]
-				if filt(svc.Service) {
-					continue
-				}
-				dump.Services = append(dump.Services[:i], dump.Services[i+1:]...)
-				i--
-			}
-
-			// Filter the checks
-			for i := 0; i < len(dump.Checks); i++ {
-				chk := dump.Checks[i]
-				if filt(chk.ServiceName) {
-					continue
-				}
-				dump.Checks = append(dump.Checks[:i], dump.Checks[i+1:]...)
-				i--
-			}
-		}
+		filt.filterNodeDump(&v.Dump)
 	}
 
 	return nil

consul/catalog_endpoint.go

@@ -126,7 +126,7 @@ func (c *Catalog) ListNodes(args *structs.DCSpecificRequest, reply *structs.Inde
 		state.QueryTables("Nodes"),
 		func() error {
 			reply.Index, reply.Nodes = state.Nodes()
-			return c.srv.applyDiscoveryACLs(args.Token, reply)
+			return c.srv.aclFilter(args.Token, reply)
 		})
 }
 
@@ -143,7 +143,7 @@ func (c *Catalog) ListServices(args *structs.DCSpecificRequest, reply *structs.I
 		state.QueryTables("Services"),
 		func() error {
 			reply.Index, reply.Services = state.Services()
-			return c.srv.applyDiscoveryACLs(args.Token, reply)
+			return c.srv.aclFilter(args.Token, reply)
 		})
 }
 
@@ -169,7 +169,7 @@ func (c *Catalog) ServiceNodes(args *structs.ServiceSpecificRequest, reply *stru
 			} else {
 				reply.Index, reply.ServiceNodes = state.ServiceNodes(args.ServiceName)
 			}
-			return c.srv.applyDiscoveryACLs(args.Token, reply)
+			return c.srv.aclFilter(args.Token, reply)
 		})
 
 	// Provide some metrics
@@ -203,6 +203,6 @@ func (c *Catalog) NodeServices(args *structs.NodeSpecificRequest, reply *structs
 		state.QueryTables("NodeServices"),
 		func() error {
 			reply.Index, reply.NodeServices = state.NodeServices(args.Node)
-			return c.srv.applyDiscoveryACLs(args.Token, reply)
+			return c.srv.aclFilter(args.Token, reply)
 		})
 }

consul/health_endpoint.go

@@ -43,7 +43,7 @@ func (h *Health) NodeChecks(args *structs.NodeSpecificRequest,
 		state.QueryTables("NodeChecks"),
 		func() error {
 			reply.Index, reply.HealthChecks = state.NodeChecks(args.Node)
-			return h.srv.applyDiscoveryACLs(args.Token, reply)
+			return h.srv.aclFilter(args.Token, reply)
 		})
 }
 
@@ -67,7 +67,7 @@ func (h *Health) ServiceChecks(args *structs.ServiceSpecificRequest,
 		state.QueryTables("ServiceChecks"),
 		func() error {
 			reply.Index, reply.HealthChecks = state.ServiceChecks(args.ServiceName)
-			return h.srv.applyDiscoveryACLs(args.Token, reply)
+			return h.srv.aclFilter(args.Token, reply)
 		})
 }
 
@@ -93,7 +93,7 @@ func (h *Health) ServiceNodes(args *structs.ServiceSpecificRequest, reply *struc
 			} else {
 				reply.Index, reply.Nodes = state.CheckServiceNodes(args.ServiceName)
 			}
-			return h.srv.applyDiscoveryACLs(args.Token, reply)
+			return h.srv.aclFilter(args.Token, reply)
 		})
 
 	// Provide some metrics

consul/internal_endpoint.go

@@ -25,8 +25,12 @@ func (m *Internal) NodeInfo(args *structs.NodeSpecificRequest,
 		&reply.QueryMeta,
 		state.QueryTables("NodeInfo"),
 		func() error {
-			reply.Index, reply.Dump = state.NodeInfo(args.Node)
-			return m.srv.applyDiscoveryACLs(args.Token, reply)
+			index, dump := state.NodeInfo(args.Node)
+			if err := m.srv.aclFilter(args.Token, &dump); err != nil {
+				return err
+			}
+			reply.Index, reply.Dump = index, dump
+			return nil
 		})
 }
 
@@ -43,8 +47,12 @@ func (m *Internal) NodeDump(args *structs.DCSpecificRequest,
 		&reply.QueryMeta,
 		state.QueryTables("NodeDump"),
 		func() error {
-			reply.Index, reply.Dump = state.NodeDump()
-			return m.srv.applyDiscoveryACLs(args.Token, reply)
+			index, dump := state.NodeDump()
+			if err := m.srv.aclFilter(args.Token, &dump); err != nil {
+				return err
+			}
+			reply.Index, reply.Dump = index, dump
+			return nil
 		})
 }