cmd/geth: test for logging-output (ethereum#28373)

This PR is a bit in preparation for the slog work in ethereum#28187 .

Our current test re logging mostly test the internals, but we have no real end-to-end test of the logging output. This PR introduces a simple reexec-based log tester. This also relies upon a special mode in geth, which can be made to eject a set of predefined log messages (only available if the build-tag `integrationtests` is used

e.g. go run --tags=integrationtests ./cmd/geth --log.format terminal logtest

While working on this, I also noticed a quirk in the setup: when geth was configured to use a file output, then two separate handlers were used (one handler for the file, one handler for the console). Using two separate handlers means that two formatters are used, thus the formatting of any/all records happened twice. This PR changes the mechanism to use two separate io.Writers instead, which is both more optimal and fixes a bug which occurs due to a global statefulness in the formatter.

build/ci.go

@@ -307,6 +307,9 @@ func doTest(cmdline []string) {
 	// Enable CKZG backend in CI.
 	gotest.Args = append(gotest.Args, "-tags=ckzg")
 
+	// Enable integration-tests
+	gotest.Args = append(gotest.Args, "-tags=integrationtests")
+
 	// Test a single package at a time. CI builders are slow
 	// and some tests run into timeouts under load.
 	gotest.Args = append(gotest.Args, "-p", "1")

cmd/geth/logging_test.go

@@ -0,0 +1,185 @@
+//go:build integrationtests
+
+// Copyright 2023 The go-ethereum Authors
+// This file is part of go-ethereum.
+//
+// go-ethereum is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// go-ethereum is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
+
+package main
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"io"
+	"math/rand"
+	"os"
+	"os/exec"
+	"strings"
+	"testing"
+
+	"github.com/docker/docker/pkg/reexec"
+)
+
+func runSelf(args ...string) ([]byte, error) {
+	cmd := &exec.Cmd{
+		Path: reexec.Self(),
+		Args: append([]string{"geth-test"}, args...),
+	}
+	return cmd.CombinedOutput()
+}
+
+func split(input io.Reader) []string {
+	var output []string
+	scanner := bufio.NewScanner(input)
+	scanner.Split(bufio.ScanLines)
+	for scanner.Scan() {
+		output = append(output, strings.TrimSpace(scanner.Text()))
+	}
+	return output
+}
+
+func censor(input string, start, end int) string {
+	if len(input) < end {
+		return input
+	}
+	return input[:start] + strings.Repeat("X", end-start) + input[end:]
+}
+
+func TestLogging(t *testing.T) {
+	testConsoleLogging(t, "terminal", 6, 24)
+	testConsoleLogging(t, "logfmt", 2, 26)
+}
+
+func testConsoleLogging(t *testing.T, format string, tStart, tEnd int) {
+	haveB, err := runSelf("--log.format", format, "logtest")
+	if err != nil {
+		t.Fatal(err)
+	}
+	readFile, err := os.Open(fmt.Sprintf("testdata/logging/logtest-%v.txt", format))
+	if err != nil {
+		t.Fatal(err)
+	}
+	wantLines := split(readFile)
+	haveLines := split(bytes.NewBuffer(haveB))
+	for i, want := range wantLines {
+		if i > len(haveLines)-1 {
+			t.Fatalf("format %v, line %d missing, want:%v", format, i, want)
+		}
+		have := haveLines[i]
+		for strings.Contains(have, "Unknown config environment variable") {
+			// This can happen on CI runs. Drop it.
+			haveLines = append(haveLines[:i], haveLines[i+1:]...)
+			have = haveLines[i]
+		}
+
+		// Black out the timestamp
+		have = censor(have, tStart, tEnd)
+		want = censor(want, tStart, tEnd)
+		if have != want {
+			t.Logf(nicediff([]byte(have), []byte(want)))
+			t.Fatalf("format %v, line %d\nhave %v\nwant %v", format, i, have, want)
+		}
+	}
+	if len(haveLines) != len(wantLines) {
+		t.Errorf("format %v, want %d lines, have %d", format, len(haveLines), len(wantLines))
+	}
+}
+
+func TestVmodule(t *testing.T) {
+	checkOutput := func(level int, want, wantNot string) {
+		t.Helper()
+		output, err := runSelf("--log.format", "terminal", "--verbosity=0", "--log.vmodule", fmt.Sprintf("logtestcmd_active.go=%d", level), "logtest")
+		if err != nil {
+			t.Fatal(err)
+		}
+		if len(want) > 0 && !strings.Contains(string(output), want) { // trace should be present at 5
+			t.Errorf("failed to find expected string ('%s') in output", want)
+		}
+		if len(wantNot) > 0 && strings.Contains(string(output), wantNot) { // trace should be present at 5
+			t.Errorf("string ('%s') should not be present in output", wantNot)
+		}
+	}
+	checkOutput(5, "log at level trace", "")                   // trace should be present at 5
+	checkOutput(4, "log at level debug", "log at level trace") // debug should be present at 4, but trace should be missing
+	checkOutput(3, "log at level info", "log at level debug")  // info should be present at 3, but debug should be missing
+	checkOutput(2, "log at level warn", "log at level info")   // warn should be present at 2, but info should be missing
+	checkOutput(1, "log at level error", "log at level warn")  // error should be present at 1, but warn should be missing
+}
+
+func nicediff(have, want []byte) string {
+	var i = 0
+	for ; i < len(have) && i < len(want); i++ {
+		if want[i] != have[i] {
+			break
+		}
+	}
+	var end = i + 40
+	var start = i - 50
+	if start < 0 {
+		start = 0
+	}
+	var h, w string
+	if end < len(have) {
+		h = string(have[start:end])
+	} else {
+		h = string(have[start:])
+	}
+	if end < len(want) {
+		w = string(want[start:end])
+	} else {
+		w = string(want[start:])
+	}
+	return fmt.Sprintf("have vs want:\n%q\n%q\n", h, w)
+}
+
+func TestFileOut(t *testing.T) {
+	var (
+		have, want []byte
+		err        error
+		path       = fmt.Sprintf("%s/test_file_out-%d", os.TempDir(), rand.Int63())
+	)
+	t.Cleanup(func() { os.Remove(path) })
+	if want, err = runSelf(fmt.Sprintf("--log.file=%s", path), "logtest"); err != nil {
+		t.Fatal(err)
+	}
+	if have, err = os.ReadFile(path); err != nil {
+		t.Fatal(err)
+	}
+	if !bytes.Equal(have, want) {
+		// show an intelligent diff
+		t.Logf(nicediff(have, want))
+		t.Errorf("file content wrong")
+	}
+}
+
+func TestRotatingFileOut(t *testing.T) {
+	var (
+		have, want []byte
+		err        error
+		path       = fmt.Sprintf("%s/test_file_out-%d", os.TempDir(), rand.Int63())
+	)
+	t.Cleanup(func() { os.Remove(path) })
+	if want, err = runSelf(fmt.Sprintf("--log.file=%s", path), "--log.rotate", "logtest"); err != nil {
+		t.Fatal(err)
+	}
+	if have, err = os.ReadFile(path); err != nil {
+		t.Fatal(err)
+	}
+	if !bytes.Equal(have, want) {
+		// show an intelligent diff
+		t.Logf(nicediff(have, want))
+		t.Errorf("file content wrong")
+	}
+}

cmd/geth/logtestcmd_active.go

@@ -0,0 +1,134 @@
+//go:build integrationtests
+
+// Copyright 2023 The go-ethereum Authors
+// This file is part of go-ethereum.
+//
+// go-ethereum is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// go-ethereum is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
+
+package main
+
+import (
+	"fmt"
+	"math"
+	"math/big"
+	"time"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/holiman/uint256"
+	"github.com/urfave/cli/v2"
+)
+
+var logTestCommand = &cli.Command{
+	Action:    logTest,
+	Name:      "logtest",
+	Usage:     "Print some log messages",
+	ArgsUsage: " ",
+	Description: `
+This command is only meant for testing.
+`}
+
+// logTest is an entry point which spits out some logs. This is used by testing
+// to verify expected outputs
+func logTest(ctx *cli.Context) error {
+	log.ResetGlobalState()
+	{ // big.Int
+		ba, _ := new(big.Int).SetString("111222333444555678999", 10)    // "111,222,333,444,555,678,999"
+		bb, _ := new(big.Int).SetString("-111222333444555678999", 10)   // "-111,222,333,444,555,678,999"
+		bc, _ := new(big.Int).SetString("11122233344455567899900", 10)  // "11,122,233,344,455,567,899,900"
+		bd, _ := new(big.Int).SetString("-11122233344455567899900", 10) // "-11,122,233,344,455,567,899,900"
+		log.Info("big.Int", "111,222,333,444,555,678,999", ba)
+		log.Info("-big.Int", "-111,222,333,444,555,678,999", bb)
+		log.Info("big.Int", "11,122,233,344,455,567,899,900", bc)
+		log.Info("-big.Int", "-11,122,233,344,455,567,899,900", bd)
+	}
+	{ //uint256
+		ua, _ := uint256.FromDecimal("111222333444555678999")
+		ub, _ := uint256.FromDecimal("11122233344455567899900")
+		log.Info("uint256", "111,222,333,444,555,678,999", ua)
+		log.Info("uint256", "11,122,233,344,455,567,899,900", ub)
+	}
+	{ // int64
+		log.Info("int64", "1,000,000", int64(1000000))
+		log.Info("int64", "-1,000,000", int64(-1000000))
+		log.Info("int64", "9,223,372,036,854,775,807", int64(math.MaxInt64))
+		log.Info("int64", "-9,223,372,036,854,775,808", int64(math.MinInt64))
+	}
+	{ // uint64
+		log.Info("uint64", "1,000,000", uint64(1000000))
+		log.Info("uint64", "18,446,744,073,709,551,615", uint64(math.MaxUint64))
+	}
+	{ // Special characters
+		log.Info("Special chars in value", "key", "special \r\n\t chars")
+		log.Info("Special chars in key", "special \n\t chars", "value")
+
+		log.Info("nospace", "nospace", "nospace")
+		log.Info("with space", "with nospace", "with nospace")
+
+		log.Info("Bash escapes in value", "key", "\u001b[1G\u001b[K\u001b[1A")
+		log.Info("Bash escapes in key", "\u001b[1G\u001b[K\u001b[1A", "value")
+
+		log.Info("Bash escapes in message  \u001b[1G\u001b[K\u001b[1A end", "key", "value")
+
+		colored := fmt.Sprintf("\u001B[%dmColored\u001B[0m[", 35)
+		log.Info(colored, colored, colored)
+	}
+	{ // Custom Stringer() - type
+		log.Info("Custom Stringer value", "2562047h47m16.854s", common.PrettyDuration(time.Duration(9223372036854775807)))
+	}
+	{ // Lazy eval
+		log.Info("Lazy evaluation of value", "key", log.Lazy{Fn: func() interface{} { return "lazy value" }})
+	}
+	{ // Multi-line message
+		log.Info("A message with wonky \U0001F4A9 characters")
+		log.Info("A multiline message \nINFO [10-18|14:11:31.106] with wonky characters \U0001F4A9")
+		log.Info("A multiline message \nLALA [ZZZZZZZZZZZZZZZZZZ] Actually part of message above")
+	}
+	{ // Miscellaneous json-quirks
+		// This will check if the json output uses strings or json-booleans to represent bool values
+		log.Info("boolean", "true", true, "false", false)
+		// Handling of duplicate keys.
+		// This is actually ill-handled by the current handler: the format.go
+		// uses a global 'fieldPadding' map and mixes up the two keys. If 'alpha'
+		// is shorter than beta, it sometimes causes erroneous padding -- and what's more
+		// it causes _different_ padding in multi-handler context, e.g. both file-
+		// and console output, making the two mismatch.
+		log.Info("repeated-key 1", "foo", "alpha", "foo", "beta")
+		log.Info("repeated-key 2", "xx", "short", "xx", "longer")
+	}
+	{ // loglevels
+		log.Debug("log at level debug")
+		log.Trace("log at level trace")
+		log.Info("log at level info")
+		log.Warn("log at level warn")
+		log.Error("log at level error")
+	}
+	{
+		// The current log formatter has a global map of paddings, storing the
+		// longest seen padding per key in a map. This results in a statefulness
+		// which has some odd side-effects. Demonstrated here:
+		log.Info("test", "bar", "short", "a", "aligned left")
+		log.Info("test", "bar", "a long message", "a", 1)
+		log.Info("test", "bar", "short", "a", "aligned right")
+	}
+	{
+		// This sequence of logs should be output with alignment, so each field becoems a column.
+		log.Info("The following logs should align so that the key-fields make 5 columns")
+		log.Info("Inserted known block", "number", 1_012, "hash", common.HexToHash("0x1234"), "txs", 200, "gas", 1_123_123, "other", "first")
+		log.Info("Inserted new block", "number", 1, "hash", common.HexToHash("0x1235"), "txs", 2, "gas", 1_123, "other", "second")
+		log.Info("Inserted known block", "number", 99, "hash", common.HexToHash("0x12322"), "txs", 10, "gas", 1, "other", "third")
+		log.Warn("Inserted known block", "number", 1_012, "hash", common.HexToHash("0x1234"), "txs", 200, "gas", 99, "other", "fourth")
+	}
+	return nil
+}

cmd/geth/logtestcmd_inactive.go

@@ -0,0 +1,23 @@
+//go:build !integrationtests
+
+// Copyright 2023 The go-ethereum Authors
+// This file is part of go-ethereum.
+//
+// go-ethereum is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// go-ethereum is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
+
+package main
+
+import "github.com/urfave/cli/v2"
+
+var logTestCommand *cli.Command

cmd/geth/main.go

@@ -234,6 +234,9 @@ func init() {
 		// See verkle.go
 		verkleCommand,
 	}
+	if logTestCommand != nil {
+		app.Commands = append(app.Commands, logTestCommand)
+	}
 	sort.Sort(cli.CommandsByName(app.Commands))
 
 	app.Flags = flags.Merge(