diff --git a/libnetwork/sandbox_dns_unix.go b/libnetwork/sandbox_dns_unix.go index afa3e793fe..24846f7649 100644 --- a/libnetwork/sandbox_dns_unix.go +++ b/libnetwork/sandbox_dns_unix.go @@ -362,7 +362,7 @@ func (sb *sandbox) rebuildDNS() error { dnsOpt: for _, resOpt := range resOptions { if strings.Contains(resOpt, "ndots") { - for _, option := range dnsOptionsList { + for i, option := range dnsOptionsList { if strings.Contains(option, "ndots") { parts := strings.Split(option, ":") if len(parts) != 2 { @@ -371,7 +371,10 @@ dnsOpt: if num, err := strconv.Atoi(parts[1]); err != nil { return fmt.Errorf("invalid number for ndots option %v", option) } else if num > 0 { + // if the user sets ndots, we mark it as set but we remove the option to guarantee + // that into the container land only ndots:0 sb.ndotsSet = true + dnsOptionsList = append(dnsOptionsList[:i], dnsOptionsList[i+1:]...) break dnsOpt } } diff --git a/libnetwork/service_common_test.go b/libnetwork/service_common_test.go index 3a0c2f1807..5b6cae937c 100644 --- a/libnetwork/service_common_test.go +++ b/libnetwork/service_common_test.go @@ -4,6 +4,8 @@ import ( "net" "testing" + "github.com/docker/libnetwork/resolvconf" + "github.com/stretchr/testify/assert" "github.com/stretchr/testify/require" ) @@ -43,3 +45,25 @@ func TestCleanupServiceDiscovery(t *testing.T) { t.Fatalf("Service record not cleaned correctly:%v", c.(*controller).svcRecords) } } + +func TestDNSOptions(t *testing.T) { + c, err := New() + require.NoError(t, err) + + sb, err := c.(*controller).NewSandbox("cnt1", nil) + require.NoError(t, err) + defer sb.Delete() + sb.(*sandbox).startResolver(false) + + sb.(*sandbox).config.dnsOptionsList = []string{"ndots:5"} + err = sb.(*sandbox).setupDNS() + require.NoError(t, err) + err = sb.(*sandbox).rebuildDNS() + require.NoError(t, err) + + currRC, err := resolvconf.GetSpecific(sb.(*sandbox).config.resolvConfPath) + require.NoError(t, err) + dnsOptionsList := resolvconf.GetOptions(currRC.Content) + assert.Equal(t, 1, len(dnsOptionsList), "There should be only 1 option instead:", dnsOptionsList) + assert.Equal(t, "ndots:0", dnsOptionsList[0], "The option must be ndots:0 instead:", dnsOptionsList[0]) +}