tailscale/logpolicy/logpolicy_test.go

// Copyright (c) Tailscale Inc & contributors
// SPDX-License-Identifier: BSD-3-Clause

package logpolicy

import (
	"context"
	"net/http"
	"net/netip"
	"os"
	"reflect"
	"sync/atomic"
	"testing"

	"tailscale.com/logtail"
	"tailscale.com/net/dnscache"
	"tailscale.com/net/memnet"
	"tailscale.com/tstest"
)

func resetLogTarget() {
	os.Unsetenv("TS_LOG_TARGET")
	v := reflect.ValueOf(&getLogTargetOnce).Elem()
	v.Set(reflect.Zero(v.Type()))
}

func TestLogHost(t *testing.T) {
	defer resetLogTarget()

	tests := []struct {
		env  string
		want string
	}{
		{"", logtail.DefaultHost},
		{"http://foo.com", "foo.com"},
		{"https://foo.com", "foo.com"},
		{"https://foo.com/", "foo.com"},
		{"https://foo.com:123/", "foo.com"},
	}
	for _, tt := range tests {
		resetLogTarget()
		os.Setenv("TS_LOG_TARGET", tt.env)
		if got := LogHost(); got != tt.want {
			t.Errorf("for env %q, got %q, want %q", tt.env, got, tt.want)
		}
	}
}
func TestOptions(t *testing.T) {
	defer resetLogTarget()

	tests := []struct {
		name        string
		opts        func() Options
		wantBaseURL string
	}{
		{
			name:        "default",
			opts:        func() Options { return Options{} },
			wantBaseURL: "",
		},
		{
			name: "custom_baseurl",
			opts: func() Options {
				os.Setenv("TS_LOG_TARGET", "http://localhost:1234")
				return Options{}
			},
			wantBaseURL: "http://localhost:1234",
		},
		{
			name: "custom_httpc_and_baseurl",
			opts: func() Options {
				os.Setenv("TS_LOG_TARGET", "http://localhost:12345")
				return Options{HTTPC: &http.Client{Transport: noopPretendSuccessTransport{}}}
			},
			wantBaseURL: "http://localhost:12345",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			resetLogTarget()
			config, policy := tt.opts().init(false)
			if policy == nil {
				t.Fatal("unexpected nil policy")
			}
			if config.BaseURL != tt.wantBaseURL {
				t.Errorf("got %q, want %q", config.BaseURL, tt.wantBaseURL)
			}
			policy.Close()
		})
	}
}

// TestInvalidLogTarget is a test for #17792
func TestInvalidLogTarget(t *testing.T) {
	defer resetLogTarget()

	tests := []struct {
		name      string
		logTarget string
	}{
		{
			name:      "invalid_url_no_scheme",
			logTarget: "not a url at all",
		},
		{
			name:      "malformed_url",
			logTarget: "ht!tp://invalid",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			resetLogTarget()
			os.Setenv("TS_LOG_TARGET", tt.logTarget)

			opts := Options{
				Collection: "test.log.tailscale.io",
				Logf:       t.Logf,
			}

			// This should not panic even with invalid log target
			config, policy := opts.init(false)
			if policy == nil {
				t.Fatal("expected non-nil policy")
			}
			defer policy.Close()

			// When log target is invalid, it should fall back to the invalid value
			// but not crash. BaseURL should remain empty
			if config.BaseURL != "" {
				t.Errorf("got BaseURL=%q, want empty", config.BaseURL)
			}
		})
	}
}

// TestDialSharesDNSCache verifies that repeated dials, including from
// separate dial funcs (as used by separate log transports), share one DNS
// lookup.
func TestDialSharesDNSCache(t *testing.T) {
	var mn memnet.Network
	ln, err := mn.Listen("tcp", "127.0.0.1:443")
	if err != nil {
		t.Fatal(err)
	}
	defer ln.Close()
	go func() {
		for {
			c, err := ln.Accept()
			if err != nil {
				return
			}
			c.Close()
		}
	}()

	var lookups atomic.Int32
	tstest.Replace(t, &logDNSCache, &dnscache.Resolver{
		UseLastGood: true,
		LookupIPForTest: func(ctx context.Context, host string) ([]netip.Addr, error) {
			lookups.Add(1)
			return []netip.Addr{netip.MustParseAddr("127.0.0.1")}, nil
		},
	})

	for range 2 {
		dial := makeDialFunc(mn.Dial, nil, t.Logf)
		for range 3 {
			c, err := dial(t.Context(), "tcp", "log.example.com:443")
			if err != nil {
				t.Fatal(err)
			}
			c.Close()
		}
	}
	if got := lookups.Load(); got != 1 {
		t.Errorf("got %d DNS lookups; want 1", got)
	}
}