From 5f45d8f8e66d581d5ad9d25d1e2fe606a4fac156 Mon Sep 17 00:00:00 2001
From: Brad Fitzpatrick <bradfitz@tailscale.com>
Date: Tue, 10 Aug 2021 13:38:12 -0700
Subject: [PATCH] tsweb: add VarzHandler tests
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
---
tsweb/tsweb.go | 4 +-
tsweb/tsweb_test.go | 105 ++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 108 insertions(+), 1 deletion(-)
diff --git a/tsweb/tsweb.go b/tsweb/tsweb.go
index 6a467a487..ab2cfe924 100644
--- a/tsweb/tsweb.go
+++ b/tsweb/tsweb.go
@@ -424,11 +424,13 @@ func VarzHandler(w http.ResponseWriter, r *http.Request) {
})
}
}
- expvar.Do(func(kv expvar.KeyValue) {
+ expvarDo(func(kv expvar.KeyValue) {
dump("", kv)
})
}
+var expvarDo = expvar.Do // pulled out for tests
+
func writeMemstats(w io.Writer, ms *runtime.MemStats) {
out := func(name, typ string, v uint64, help string) {
if help != "" {
diff --git a/tsweb/tsweb_test.go b/tsweb/tsweb_test.go
index 5e0dfe9c2..f9bda99cc 100644
--- a/tsweb/tsweb_test.go
+++ b/tsweb/tsweb_test.go
@@ -8,6 +8,7 @@ import (
"bufio"
"context"
"errors"
+ "expvar"
"net"
"net/http"
"net/http/httptest"
@@ -15,6 +16,7 @@ import (
"time"
"github.com/google/go-cmp/cmp"
+ "tailscale.com/metrics"
"tailscale.com/tstest"
)
@@ -300,3 +302,106 @@ func BenchmarkLog(b *testing.B) {
h.ServeHTTP(rw, req)
}
}
+
+func TestVarzHandler(t *testing.T) {
+ tests := []struct {
+ name string
+ k string // key name
+ v expvar.Var
+ want string
+ }{
+ {
+ "int",
+ "foo",
+ new(expvar.Int),
+ "# TYPE foo counter\nfoo 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",
+ },
+ {
+ "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_guage_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",
+ },
+ {
+ "func_float64",
+ "counter_x",
+ expvar.Func(func() interface{} { return float64(1.2) }),
+ "# TYPE x counter\nx 1.2\n",
+ },
+ {
+ "func_float64_gauge",
+ "gauge_x",
+ expvar.Func(func() interface{} { return float64(1.2) }),
+ "# TYPE x gauge\nx 1.2\n",
+ },
+ {
+ "func_float64_untyped",
+ "x",
+ expvar.Func(func() interface{} { return float64(1.2) }),
+ "# skipping expvar \"x\" (Go type expvar.Func returning float64) with undeclared Prometheus type\n",
+ },
+ {
+ "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",
+ },
+ }
+ for _, tt := range tests {
+ t.Run(tt.name, func(t *testing.T) {
+ defer func() { expvarDo = expvar.Do }()
+ expvarDo = func(f func(expvar.KeyValue)) {
+ f(expvar.KeyValue{Key: tt.k, Value: tt.v})
+ }
+ rec := httptest.NewRecorder()
+ VarzHandler(rec, httptest.NewRequest("GET", "/", nil))
+ if got := rec.Body.Bytes(); string(got) != tt.want {
+ t.Errorf("mismatch\n got: %q\nwant: %q\n", got, tt.want)
+ }
+ })
+ }
+
+}