Search handles prefix longer than allowed UUIDs

This PR fixes an issue in which the Search endpoint would error if the
prefix was longer than the allowed 36 characters of a UUID.

Fixes https://github.com/hashicorp/nomad/issues/3134

nomad/search_endpoint.go

@@ -125,9 +125,13 @@ func (s *Search) PrefixSearch(args *structs.SearchRequest,
 				iter, err := getResourceIter(ctx, roundUUIDDownIfOdd(args.Prefix, args.Context), ws, state)
 
 				if err != nil {
+					e := err.Error()
+					switch {
 					// Searching other contexts with job names raises an error, which in
 					// this case we want to ignore.
-					if !strings.Contains(err.Error(), "Invalid UUID: encoding/hex") {
+					case strings.Contains(e, "Invalid UUID: encoding/hex"):
+					case strings.Contains(e, "UUID have 36 characters"):
+					default:
 						return err
 					}
 				} else {

nomad/search_endpoint_test.go

@@ -2,6 +2,7 @@ package nomad
 
 import (
 	"strconv"
+	"strings"
 	"testing"
 
 	msgpackrpc "github.com/hashicorp/net-rpc-msgpackrpc"
@@ -97,6 +98,48 @@ func TestSearch_PrefixSearch_All_JobWithHyphen(t *testing.T) {
 	assert.EqualValues(jobIndex, resp.Index)
 }
 
+func TestSearch_PrefixSearch_All_LongJob(t *testing.T) {
+	assert := assert.New(t)
+	prefix := strings.Repeat("a", 100)
+
+	t.Parallel()
+	s := testServer(t, func(c *Config) {
+		c.NumSchedulers = 0
+	})
+
+	defer s.Shutdown()
+	codec := rpcClient(t, s)
+	testutil.WaitForLeader(t, s.RPC)
+
+	// Register a job and an allocation
+	jobID := registerAndVerifyJob(s, t, prefix, 0)
+	alloc := mock.Alloc()
+	alloc.JobID = jobID
+	summary := mock.JobSummary(alloc.JobID)
+	state := s.fsm.State()
+
+	if err := state.UpsertJobSummary(999, summary); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	if err := state.UpsertAllocs(1000, []*structs.Allocation{alloc}); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	req := &structs.SearchRequest{
+		Prefix:  prefix,
+		Context: structs.All,
+	}
+
+	var resp structs.SearchResponse
+	if err := msgpackrpc.CallWithCodec(codec, "Search.PrefixSearch", req, &resp); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	assert.Equal(1, len(resp.Matches[structs.Jobs]))
+	assert.Equal(jobID, resp.Matches[structs.Jobs][0])
+	assert.EqualValues(jobIndex, resp.Index)
+}
+
 // truncate should limit results to 20
 func TestSearch_PrefixSearch_Truncate(t *testing.T) {
 	assert := assert.New(t)