dynamic host volumes: search endpoint

Add support for dynamic host volumes to the search endpoint. Like many other
objects with UUID identifiers, we're not supporting fuzzy search here, just
prefix search on the fuzzy search endpoint.

Because the search endpoint only returns IDs, we need to seperate CSI volumes
and host volumes for it to be useful. The new context is called `"host_volumes"`
to disambiguate it from `"volumes"`. In future versions of Nomad we should
consider deprecating the `"volumes"` context in lieu of a `"csi_volumes"`
context.

Ref: #24479

api/contexts/contexts.go

@@ -23,6 +23,7 @@ const (
 	Plugins         Context = "plugins"
 	Variables       Context = "vars"
 	Volumes         Context = "volumes"
+	HostVolumes     Context = "host_volumes"
 
 	// These Context types are used to associate a search result from a lower
 	// level Nomad object with one of the higher level Context types above.

nomad/search_endpoint.go

@@ -41,6 +41,7 @@ var (
 		structs.ScalingPolicies,
 		structs.Variables,
 		structs.Namespaces,
+		structs.HostVolumes,
 	}
 )
 
@@ -84,6 +85,8 @@ func (s *Search) getPrefixMatches(iter memdb.ResultIterator, prefix string) ([]s
 			id = t.ID
 		case *structs.CSIVolume:
 			id = t.ID
+		case *structs.HostVolume:
+			id = t.ID
 		case *structs.ScalingPolicy:
 			id = t.ID
 		case *structs.Namespace:
@@ -405,6 +408,8 @@ func getResourceIter(context structs.Context, aclObj *acl.ACL, namespace, prefix
 		return store.ScalingPoliciesByIDPrefix(ws, namespace, prefix)
 	case structs.Volumes:
 		return store.CSIVolumesByIDPrefix(ws, namespace, prefix)
+	case structs.HostVolumes:
+		return store.HostVolumesByIDPrefix(ws, namespace, prefix, state.SortDefault)
 	case structs.Namespaces:
 		iter, err := store.NamespacesByNamePrefix(ws, prefix)
 		if err != nil {
@@ -684,6 +689,8 @@ func sufficientSearchPerms(aclObj *acl.ACL, namespace string, context structs.Co
 			acl.NamespaceCapabilityCSIReadVolume,
 			acl.NamespaceCapabilityListJobs,
 			acl.NamespaceCapabilityReadJob)(aclObj, namespace)
+	case structs.HostVolumes:
+		return acl.NamespaceValidator(acl.NamespaceCapabilityHostVolumeRead)(aclObj, namespace)
 	case structs.Variables:
 		return aclObj.AllowVariableSearch(namespace)
 	case structs.Plugins:
@@ -774,7 +781,8 @@ func (s *Search) FuzzySearch(args *structs.FuzzySearchRequest, reply *structs.Fu
 			for _, ctx := range prefixContexts {
 				switch ctx {
 				// only apply on the types that use UUID prefix searching
-				case structs.Evals, structs.Deployments, structs.ScalingPolicies, structs.Volumes, structs.Quotas, structs.Recommendations:
+				case structs.Evals, structs.Deployments, structs.ScalingPolicies,
+					structs.Volumes, structs.HostVolumes, structs.Quotas, structs.Recommendations:
 					iter, err := getResourceIter(ctx, aclObj, namespace, roundUUIDDownIfOdd(args.Prefix, args.Context), ws, state)
 					if err != nil {
 						if !s.silenceError(err) {
@@ -790,7 +798,9 @@ func (s *Search) FuzzySearch(args *structs.FuzzySearchRequest, reply *structs.Fu
 			for _, ctx := range fuzzyContexts {
 				switch ctx {
 				// skip the types that use UUID prefix searching
-				case structs.Evals, structs.Deployments, structs.ScalingPolicies, structs.Volumes, structs.Quotas, structs.Recommendations:
+				case structs.Evals, structs.Deployments, structs.ScalingPolicies,
+					structs.Volumes, structs.HostVolumes, structs.Quotas,
+					structs.Recommendations:
 					continue
 				default:
 					iter, err := getFuzzyResourceIterator(ctx, aclObj, namespace, ws, state)
@@ -927,6 +937,11 @@ func filteredSearchContexts(aclObj *acl.ACL, namespace string, context structs.C
 			if volRead {
 				available = append(available, c)
 			}
+		case structs.HostVolumes:
+			if acl.NamespaceValidator(
+				acl.NamespaceCapabilityHostVolumeRead)(aclObj, namespace) {
+				available = append(available, c)
+			}
 		case structs.Plugins:
 			if aclObj.AllowPluginList() {
 				available = append(available, c)

nomad/search_endpoint_test.go

@@ -1039,6 +1039,53 @@ func TestSearch_PrefixSearch_CSIVolume(t *testing.T) {
 	require.False(t, resp.Truncations[structs.Volumes])
 }
 
+func TestSearch_PrefixSearch_HostVolume(t *testing.T) {
+	ci.Parallel(t)
+
+	srv, cleanup := TestServer(t, func(c *Config) {
+		c.NumSchedulers = 0
+	})
+	defer cleanup()
+	codec := rpcClient(t, srv)
+	testutil.WaitForLeader(t, srv.RPC)
+
+	store := srv.fsm.State()
+	index, _ := store.LatestIndex()
+
+	node := mock.Node()
+	index++
+	must.NoError(t, store.UpsertNode(structs.MsgTypeTestSetup, index, node))
+
+	id := uuid.Generate()
+	index++
+	err := store.UpsertHostVolumes(index, []*structs.HostVolume{{
+		ID:        id,
+		Name:      "example",
+		Namespace: structs.DefaultNamespace,
+		PluginID:  "glade",
+		NodeID:    node.ID,
+		NodePool:  node.NodePool,
+	}})
+	must.NoError(t, err)
+
+	req := &structs.SearchRequest{
+		Prefix:  id[:6],
+		Context: structs.HostVolumes,
+		QueryOptions: structs.QueryOptions{
+			Region:    "global",
+			Namespace: structs.DefaultNamespace,
+		},
+	}
+
+	var resp structs.SearchResponse
+	must.NoError(t, msgpackrpc.CallWithCodec(codec, "Search.PrefixSearch", req, &resp))
+
+	must.Len(t, 1, resp.Matches[structs.HostVolumes])
+	must.Len(t, 0, resp.Matches[structs.Volumes])
+	must.Eq(t, id, resp.Matches[structs.HostVolumes][0])
+	must.False(t, resp.Truncations[structs.HostVolumes])
+}
+
 func TestSearch_PrefixSearch_Namespace(t *testing.T) {
 	ci.Parallel(t)
 
@@ -1932,6 +1979,52 @@ func TestSearch_FuzzySearch_CSIVolume(t *testing.T) {
 	require.False(t, resp.Truncations[structs.Volumes])
 }
 
+func TestSearch_FuzzySearch_HostVolume(t *testing.T) {
+	ci.Parallel(t)
+
+	srv, cleanup := TestServer(t, func(c *Config) {
+		c.NumSchedulers = 0
+	})
+	defer cleanup()
+	codec := rpcClient(t, srv)
+	testutil.WaitForLeader(t, srv.RPC)
+
+	store := srv.fsm.State()
+	index, _ := store.LatestIndex()
+
+	node := mock.Node()
+	index++
+	must.NoError(t, store.UpsertNode(structs.MsgTypeTestSetup, index, node))
+
+	id := uuid.Generate()
+	index++
+	err := store.UpsertHostVolumes(index, []*structs.HostVolume{{
+		ID:        id,
+		Name:      "example",
+		Namespace: structs.DefaultNamespace,
+		PluginID:  "glade",
+		NodeID:    node.ID,
+		NodePool:  node.NodePool,
+	}})
+	must.NoError(t, err)
+
+	req := &structs.FuzzySearchRequest{
+		Text:    id[0:3], // volumes are prefix searched
+		Context: structs.HostVolumes,
+		QueryOptions: structs.QueryOptions{
+			Region:    "global",
+			Namespace: structs.DefaultNamespace,
+		},
+	}
+
+	var resp structs.FuzzySearchResponse
+	must.NoError(t, msgpackrpc.CallWithCodec(codec, "Search.FuzzySearch", req, &resp))
+
+	must.Len(t, 1, resp.Matches[structs.HostVolumes])
+	must.Eq(t, id, resp.Matches[structs.HostVolumes][0].ID)
+	must.False(t, resp.Truncations[structs.HostVolumes])
+}
+
 func TestSearch_FuzzySearch_Namespace(t *testing.T) {
 	ci.Parallel(t)
 

nomad/state/state_store_host_volumes.go

@@ -5,6 +5,7 @@ package state
 
 import (
 	"fmt"
+	"strings"
 
 	memdb "github.com/hashicorp/go-memdb"
 	"github.com/hashicorp/nomad/nomad/structs"
@@ -156,6 +157,30 @@ func (s *StateStore) HostVolumes(ws memdb.WatchSet, sort SortOption) (memdb.Resu
 	return s.hostVolumesIter(ws, indexID, sort)
 }
 
+// HostVolumesByIDPrefix retrieves all host volumes by ID prefix. Because the ID
+// index is namespaced, we need to handle the wildcard namespace here as well.
+func (s *StateStore) HostVolumesByIDPrefix(ws memdb.WatchSet, ns, prefix string, sort SortOption) (memdb.ResultIterator, error) {
+
+	if ns != structs.AllNamespacesSentinel {
+		return s.hostVolumesIter(ws, "id_prefix", sort, ns, prefix)
+	}
+
+	// for wildcard namespace, wrap the iterator in a filter function that
+	// filters all volumes by prefix
+	iter, err := s.hostVolumesIter(ws, indexID, sort)
+	if err != nil {
+		return nil, err
+	}
+	wrappedIter := memdb.NewFilterIterator(iter, func(raw any) bool {
+		vol, ok := raw.(*structs.HostVolume)
+		if !ok {
+			return true
+		}
+		return !strings.HasPrefix(vol.ID, prefix)
+	})
+	return wrappedIter, nil
+}
+
 // HostVolumesByName retrieves all host volumes of the same name
 func (s *StateStore) HostVolumesByName(ws memdb.WatchSet, ns, name string, sort SortOption) (memdb.ResultIterator, error) {
 	return s.hostVolumesIter(ws, "name_prefix", sort, ns, name)

nomad/state/state_store_host_volumes_test.go

@@ -163,6 +163,17 @@ func TestStateStore_HostVolumes_CRUD(t *testing.T) {
 	must.NoError(t, err)
 	got = consumeIter(iter)
 	must.MapLen(t, 3, got, must.Sprint(`expected 3 volumes remain`))
+
+	prefix := vol.ID[:30] // sufficiently long prefix to avoid flakes
+	iter, err = store.HostVolumesByIDPrefix(nil, "*", prefix, SortDefault)
+	must.NoError(t, err)
+	got = consumeIter(iter)
+	must.MapLen(t, 1, got, must.Sprint(`expected only one volume to match prefix`))
+
+	iter, err = store.HostVolumesByIDPrefix(nil, vol.Namespace, prefix, SortDefault)
+	must.NoError(t, err)
+	got = consumeIter(iter)
+	must.MapLen(t, 1, got, must.Sprint(`expected only one volume to match prefix`))
 }
 
 func TestStateStore_UpdateHostVolumesFromFingerprint(t *testing.T) {

nomad/structs/search.go

@@ -22,6 +22,7 @@ const (
 	Plugins         Context = "plugins"
 	Variables       Context = "vars"
 	Volumes         Context = "volumes"
+	HostVolumes     Context = "host_volumes"
 
 	// Subtypes used in fuzzy matching.
 	Groups   Context = "groups"