// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
package varz
import (
"expvar"
"net/http/httptest"
"reflect"
"strings"
"testing"
"tailscale.com/metrics"
"tailscale.com/tstest"
"tailscale.com/version"
)
func TestVarzHandler(t *testing.T) {
t.Run("globals_log", func(t *testing.T) {
rec := httptest.NewRecorder()
Handler(rec, httptest.NewRequest("GET", "/", nil))
t.Logf("Got: %s", rec.Body.Bytes())
})
half := new(expvar.Float)
half.Set(0.5)
tests := []struct {
name string
k string // key name
v expvar.Var
want string
}{
{
"int",
"foo",
new(expvar.Int),
"# TYPE foo counter\nfoo 0\n",
},
{
"dash_in_metric_name",
"counter_foo-bar",
new(expvar.Int),
"# TYPE foo_bar counter\nfoo_bar 0\n",
},
{
"int_with_type_counter",
"counter_foo",
new(expvar.Int),
"# TYPE foo counter\nfoo 0\n",
},
{
"int_with_type_gauge",
"gauge_foo",
new(expvar.Int),
"# TYPE foo gauge\nfoo 0\n",
},
{
// For a float = 0.0, Prometheus client_golang outputs "0"
"float_zero",
"foo",
new(expvar.Float),
"# TYPE foo gauge\nfoo 0\n",
},
{
"float_point_5",
"foo",
half,
"# TYPE foo gauge\nfoo 0.5\n",
},
{
"float_with_type_counter",
"counter_foo",
half,
"# TYPE foo counter\nfoo 0.5\n",
},
{
"float_with_type_gauge",
"gauge_foo",
half,
"# TYPE foo gauge\nfoo 0.5\n",
},
{
"metrics_set",
"s",
&metrics.Set{
Map: *(func() *expvar.Map {
m := new(expvar.Map)
m.Init()
m.Add("foo", 1)
m.Add("bar", 2)
return m
})(),
},
"# TYPE s_bar counter\ns_bar 2\n# TYPE s_foo counter\ns_foo 1\n",
},
{
"metrics_set_TODO_gauge_type",
"gauge_s", // TODO(bradfitz): arguably a bug; should pass down type
&metrics.Set{
Map: *(func() *expvar.Map {
m := new(expvar.Map)
m.Init()
m.Add("foo", 1)
m.Add("bar", 2)
return m
})(),
},
"# TYPE s_bar counter\ns_bar 2\n# TYPE s_foo counter\ns_foo 1\n",
},
{
"expvar_map_untyped",
"api_status_code",
func() *expvar.Map {
m := new(expvar.Map)
m.Init()
m.Add("2xx", 100)
m.Add("5xx", 2)
return m
}(),
"api_status_code_2xx 100\napi_status_code_5xx 2\n",
},
{
"func_float64",
"counter_x",
expvar.Func(func() any { return float64(1.2) }),
"# TYPE x counter\nx 1.2\n",
},
{
"func_float64_gauge",
"gauge_y",
expvar.Func(func() any { return float64(1.2) }),
"# TYPE y gauge\ny 1.2\n",
},
{
"func_float64_untyped",
"z",
expvar.Func(func() any { return float64(1.2) }),
"z 1.2\n",
},
{
"metrics_label_map",
"counter_m",
&metrics.LabelMap{
Label: "label",
Map: *(func() *expvar.Map {
m := new(expvar.Map)
m.Init()
m.Add("foo", 1)
m.Add("bar", 2)
return m
})(),
},
"# TYPE m counter\nm{label=\"bar\"} 2\nm{label=\"foo\"} 1\n",
},
{
"metrics_label_map_untyped",
"control_save_config",
(func() *metrics.LabelMap {
m := &metrics.LabelMap{Label: "reason"}
m.Add("new", 1)
m.Add("updated", 1)
m.Add("fun", 1)
return m
})(),
"control_save_config{reason=\"fun\"} 1\ncontrol_save_config{reason=\"new\"} 1\ncontrol_save_config{reason=\"updated\"} 1\n",
},
{
"metrics_label_map_unlabeled",
"foo",
(func() *metrics.LabelMap {
m := &metrics.LabelMap{Label: ""}
m.Add("a", 1)
return m
})(),
"foo{label=\"a\"} 1\n",
},
{
"expvar_label_map",
"counter_labelmap_keyname_m",
func() *expvar.Map {
m := new(expvar.Map)
m.Init()
m.Add("foo", 1)
m.Add("bar", 2)
return m
}(),
"# TYPE m counter\nm{keyname=\"bar\"} 2\nm{keyname=\"foo\"} 1\n",
},
{
"struct_reflect",
"foo",
someExpVarWithJSONAndPromTypes(),
strings.TrimSpace(`
# TYPE foo_AUint16 counter
foo_AUint16 65535
# TYPE foo_AnInt8 counter
foo_AnInt8 127
# TYPE foo_curTemp gauge
foo_curTemp 20.6
# TYPE foo_curX gauge
foo_curX 3
# TYPE foo_nestptr_bar counter
foo_nestptr_bar 20
# TYPE foo_nestptr_foo gauge
foo_nestptr_foo 10
# TYPE foo_nestvalue_bar counter
foo_nestvalue_bar 2
# TYPE foo_nestvalue_foo gauge
foo_nestvalue_foo 1
# TYPE foo_totalY counter
foo_totalY 4
`) + "\n",
},
{
"struct_reflect_nil_root",
"foo",
expvarAdapter{(*SomeStats)(nil)},
"",
},
{
"func_returning_int",
"num_goroutines",
expvar.Func(func() any { return 123 }),
"num_goroutines 123\n",
},
{
"string_version_var",
"foo_version",
expvar.Func(func() any { return "1.2.3-foo15" }),
"foo_version{version=\"1.2.3-foo15\"} 1\n",
},
{
"field_ordering",
"foo",
someExpVarWithFieldNamesSorting(),
strings.TrimSpace(`
# TYPE foo_bar_a gauge
foo_bar_a 1
# TYPE foo_bar_b counter
foo_bar_b 1
# TYPE foo_foo_a gauge
foo_foo_a 1
# TYPE foo_foo_b counter
foo_foo_b 1
`) + "\n",
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
tstest.Replace(t, &expvarDo, func(f func(expvar.KeyValue)) {
f(expvar.KeyValue{Key: tt.k, Value: tt.v})
})
rec := httptest.NewRecorder()
Handler(rec, httptest.NewRequest("GET", "/", nil))
if got := rec.Body.Bytes(); string(got) != tt.want {
t.Errorf("mismatch\n got: %q\n%s\nwant: %q\n%s\n", got, got, tt.want, tt.want)
}
})
}
}
type SomeNested struct {
FooG int64 `json:"foo" metrictype:"gauge"`
BarC int64 `json:"bar" metrictype:"counter"`
Omit int `json:"-" metrictype:"counter"`
}
type SomeStats struct {
Nested SomeNested `json:"nestvalue"`
NestedPtr *SomeNested `json:"nestptr"`
NestedNilPtr *SomeNested `json:"nestnilptr"`
CurX int `json:"curX" metrictype:"gauge"`
NoMetricType int `json:"noMetric" metrictype:""`
TotalY int64 `json:"totalY,omitempty" metrictype:"counter"`
CurTemp float64 `json:"curTemp" metrictype:"gauge"`
AnInt8 int8 `metrictype:"counter"`
AUint16 uint16 `metrictype:"counter"`
}
// someExpVarWithJSONAndPromTypes returns an expvar.Var that
// implements PrometheusMetricsReflectRooter for TestVarzHandler.
func someExpVarWithJSONAndPromTypes() expvar.Var {
st := &SomeStats{
Nested: SomeNested{
FooG: 1,
BarC: 2,
Omit: 3,
},
NestedPtr: &SomeNested{
FooG: 10,
BarC: 20,
},
CurX: 3,
TotalY: 4,
CurTemp: 20.6,
AnInt8: 127,
AUint16: 65535,
}
return expvarAdapter{st}
}
type expvarAdapter struct {
st *SomeStats
}
func (expvarAdapter) String() string { return "{}" } // expvar JSON; unused in test
func (a expvarAdapter) PrometheusMetricsReflectRoot() any {
return a.st
}
// SomeTestOfFieldNamesSorting demonstrates field
// names that are not in sorted in declaration order, to verify
// that we sort based on field name
type SomeTestOfFieldNamesSorting struct {
FooAG int64 `json:"foo_a" metrictype:"gauge"`
BarAG int64 `json:"bar_a" metrictype:"gauge"`
FooBC int64 `json:"foo_b" metrictype:"counter"`
BarBC int64 `json:"bar_b" metrictype:"counter"`
}
// someExpVarWithFieldNamesSorting returns an expvar.Var that
// implements PrometheusMetricsReflectRooter for TestVarzHandler.
func someExpVarWithFieldNamesSorting() expvar.Var {
st := &SomeTestOfFieldNamesSorting{
FooAG: 1,
BarAG: 1,
FooBC: 1,
BarBC: 1,
}
return expvarAdapter2{st}
}
type expvarAdapter2 struct {
st *SomeTestOfFieldNamesSorting
}
func (expvarAdapter2) String() string { return "{}" } // expvar JSON; unused in test
func (a expvarAdapter2) PrometheusMetricsReflectRoot() any {
return a.st
}
func TestSortedStructAllocs(t *testing.T) {
f := reflect.ValueOf(struct {
Foo int
Bar int
Baz int
}{})
n := testing.AllocsPerRun(1000, func() {
foreachExportedStructField(f, func(fieldOrJSONName, metricType string, rv reflect.Value) {
// Nothing.
})
})
if n != 0 {
t.Errorf("allocs = %v; want 0", n)
}
}
func TestVarzHandlerSorting(t *testing.T) {
tstest.Replace(t, &expvarDo, func(f func(expvar.KeyValue)) {
f(expvar.KeyValue{Key: "counter_zz", Value: new(expvar.Int)})
f(expvar.KeyValue{Key: "gauge_aa", Value: new(expvar.Int)})
})
rec := httptest.NewRecorder()
req := httptest.NewRequest("GET", "/", nil)
Handler(rec, req)
got := rec.Body.Bytes()
const want = "# TYPE aa gauge\naa 0\n# TYPE zz counter\nzz 0\n"
if string(got) != want {
t.Errorf("got %q; want %q", got, want)
}
rec = new(httptest.ResponseRecorder) // without a body
// Lock in the current number of allocs, to prevent it from growing.
if !version.IsRace() {
allocs := int(testing.AllocsPerRun(1000, func() {
Handler(rec, req)
}))
if max := 13; allocs > max {
t.Errorf("allocs = %v; want max %v", allocs, max)
}
}
}