rebase: logger is ported (Geth 1.6 logging)

geth/params/config.go

@@ -3,17 +3,14 @@ package params
 import (
 	"encoding/json"
 	"errors"
+	"fmt"
 	"io/ioutil"
-	"math/big"
 	"os"
 	"path/filepath"
 	"strings"
 
-	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core"
-	"github.com/ethereum/go-ethereum/logger"
-	"github.com/ethereum/go-ethereum/logger/glog"
-	"github.com/ethereum/go-ethereum/params"
+	"github.com/ethereum/go-ethereum/log"
 )
 
 // default node configuration options
@@ -33,33 +30,6 @@ var (
 	ErrMissingNetworkId = errors.New("missing required 'NetworkId' parameter")
 )
 
-// ChainConfig holds core blockchain settings. It is stored in the database on a per block basis.
-type ChainConfig struct {
-	// ChainId identifies the current chain and is used for replay protection
-	ChainId *big.Int
-
-	// HomesteadBlock is Homestead switch block (nil = no fork, 0 = already homestead)
-	HomesteadBlock *big.Int
-
-	// DAOForkBlock TheDAO hard-fork switch block (nil = no fork)
-	DAOForkBlock *big.Int
-
-	// DAOForkSupport Whether the nodes supports or opposes the DAO hard-fork
-	DAOForkSupport bool
-
-	// EIP150Block is EIP150 HF block (nil = no fork)
-	EIP150Block *big.Int
-
-	// EIP150Hash is EIP150 HF hash (fast sync aid)
-	EIP150Hash common.Hash
-
-	// EIP155Block is EIP155 HF block
-	EIP155Block *big.Int
-
-	// EIP158Block is EIP158 HF block
-	EIP158Block *big.Int
-}
-
 // LightEthConfig holds LES-related configuration
 // Status nodes are always lightweight clients (due to mobile platform constraints)
 type LightEthConfig struct {
@@ -124,7 +94,7 @@ type NodeConfig struct {
 	TestNet bool
 
 	// NetworkId sets network to use for selecting peers to connect to
-	NetworkId int
+	NetworkId uint64
 
 	// DataDir is the file system folder the node should use for any data storage needs.
 	DataDir string
@@ -187,11 +157,11 @@ type NodeConfig struct {
 	// LogFile is filename where exposed logs get written to
 	LogFile string
 
-	// LogLevel defines minimum log level. Valid names are "ERROR", "WARNING", "INFO", "DEBUG", and "DETAIL".
+	// LogLevel defines minimum log level. Valid names are "ERROR", "WARNING", "INFO", "DEBUG", and "TRACE".
 	LogLevel string
 
-	// ChainConfig extra configuration for blockchain
-	*ChainConfig `json:"ChainConfig,"`
+	// LogToStderr defines whether logged info should also be output to os.Stderr
+	LogToStderr bool
 
 	// LightEthConfig extra configuration for LES
 	LightEthConfig *LightEthConfig `json:"LightEthConfig,"`
@@ -204,7 +174,7 @@ type NodeConfig struct {
 }
 
 // NewNodeConfig creates new node configuration object
-func NewNodeConfig(dataDir string, networkId int) (*NodeConfig, error) {
+func NewNodeConfig(dataDir string, networkId uint64) (*NodeConfig, error) {
 	nodeConfig := &NodeConfig{
 		NetworkId:       networkId,
 		DataDir:         dataDir,
@@ -220,7 +190,7 @@ func NewNodeConfig(dataDir string, networkId int) (*NodeConfig, error) {
 		IPCFile:         IPCFile,
 		LogFile:         LogFile,
 		LogLevel:        LogLevel,
-		ChainConfig:     &ChainConfig{},
+		LogToStderr:     LogToStderr,
 		LightEthConfig: &LightEthConfig{
 			Enabled:       true,
 			DatabaseCache: DatabaseCache,
@@ -235,14 +205,18 @@ func NewNodeConfig(dataDir string, networkId int) (*NodeConfig, error) {
 	}
 
 	// auto-populate some dependent values
-	nodeConfig.populateChainConfig()
-	nodeConfig.populateDirs()
+	if err := nodeConfig.populateGenesis(); err != nil {
+		return nil, err
+	}
+	if err := nodeConfig.populateDirs(); err != nil {
+		return nil, err
+	}
 
 	return nodeConfig, nil
 }
 
 // populateDirs updates directories that should be wrt to DataDir
-func (c *NodeConfig) populateDirs() {
+func (c *NodeConfig) populateDirs() error {
 	makeSubDirPath := func(baseDir, subDir string) string {
 		if len(baseDir) == 0 {
 			return ""
@@ -257,51 +231,32 @@ func (c *NodeConfig) populateDirs() {
 	if len(c.WhisperConfig.DataDir) == 0 {
 		c.WhisperConfig.DataDir = makeSubDirPath(c.DataDir, WhisperDataDir)
 	}
+
+	return nil
 }
 
-// populateChainConfig does necessary adjustments to config object (depending on network node will be running on)
-func (c *NodeConfig) populateChainConfig() {
+// populateChainConfig does necessary adjustments to config object (depending on network node will be runnin on)
+func (c *NodeConfig) populateGenesis() error {
 	c.TestNet = false
 	if c.NetworkId == TestNetworkId {
 		c.TestNet = true
 	}
 
+	var genesis *core.Genesis
 	if c.TestNet {
-		// Homestead fork
-		c.ChainConfig.HomesteadBlock = params.TestnetChainConfig.HomesteadBlock
-
-		// DAO fork
-		c.ChainConfig.DAOForkBlock = params.TestnetChainConfig.DAOForkBlock
-		c.ChainConfig.DAOForkSupport = params.TestnetChainConfig.DAOForkSupport
-
-		// DoS reprice fork
-		c.ChainConfig.EIP150Block = params.TestnetChainConfig.EIP150Block
-		c.ChainConfig.EIP150Hash = params.TestnetChainConfig.EIP150Hash
-
-		// DoS state cleanup fork
-		c.ChainConfig.EIP155Block = params.TestnetChainConfig.EIP155Block
-		c.ChainConfig.EIP158Block = params.TestnetChainConfig.EIP158Block
-		c.ChainConfig.ChainId = params.TestnetChainConfig.ChainId
-
-		c.LightEthConfig.Genesis = core.DefaultTestnetGenesisBlock()
+		genesis = core.DefaultTestnetGenesisBlock()
 	} else {
-		// Homestead fork
-		c.ChainConfig.HomesteadBlock = params.MainNetHomesteadBlock
-		// DAO fork
-		c.ChainConfig.DAOForkBlock = params.MainNetDAOForkBlock
-		c.ChainConfig.DAOForkSupport = true
-
-		// DoS reprice fork
-		c.ChainConfig.EIP150Block = params.MainNetHomesteadGasRepriceBlock
-		c.ChainConfig.EIP150Hash = params.MainNetHomesteadGasRepriceHash
-
-		// DoS state cleanup fork
-		c.ChainConfig.EIP155Block = params.MainNetSpuriousDragon
-		c.ChainConfig.EIP158Block = params.MainNetSpuriousDragon
-		c.ChainConfig.ChainId = params.MainNetChainID
-
-		c.LightEthConfig.Genesis = core.DefaultGenesisBlock()
+		genesis = core.DefaultGenesisBlock()
 	}
+
+	// encode the genesis into JSON
+	enc, err := json.Marshal(genesis)
+	if err != nil {
+		return err
+	}
+	c.LightEthConfig.Genesis = string(enc)
+
+	return nil
 }
 
 // LoadNodeConfig parses incoming JSON and returned it as Config
@@ -320,8 +275,12 @@ func LoadNodeConfig(configJSON string) (*NodeConfig, error) {
 	}
 
 	// repopulate
-	nodeConfig.populateChainConfig()
-	nodeConfig.populateDirs()
+	if err := nodeConfig.populateGenesis(); err != nil {
+		return nil, err
+	}
+	if err := nodeConfig.populateDirs(); err != nil {
+		return nil, err
+	}
 
 	if len(nodeConfig.DataDir) == 0 {
 		return nil, ErrMissingDataDir
@@ -350,7 +309,7 @@ func (c *NodeConfig) Save() error {
 		return err
 	}
 
-	glog.V(logger.Info).Infof("config file saved: %v", configFilePath)
+	log.Info(fmt.Sprintf("config file saved: %v", configFilePath))
 	return nil
 }
 

geth/params/config_test.go

@@ -1,12 +1,14 @@
 package params_test
 
 import (
+	"encoding/json"
 	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strings"
 	"testing"
 
+	"github.com/ethereum/go-ethereum/core"
 	gethparams "github.com/ethereum/go-ethereum/params"
 	"github.com/status-im/status-go/geth"
 	"github.com/status-im/status-go/geth/params"
@@ -190,7 +192,11 @@ var loadConfigTestCases = []struct {
 				t.Fatalf("unexpected error: %v", err)
 			}
 
-			chainConfig := nodeConfig.ChainConfig
+			genesis := new(core.Genesis)
+			if err := json.Unmarshal([]byte(nodeConfig.LightEthConfig.Genesis), genesis); err != nil {
+				t.Fatal(err)
+			}
+			chainConfig := genesis.Config
 			refChainConfig := gethparams.TestnetChainConfig
 
 			if chainConfig.HomesteadBlock.Cmp(refChainConfig.HomesteadBlock) != 0 {
@@ -237,7 +243,11 @@ var loadConfigTestCases = []struct {
 				t.Fatalf("unexpected error: %v", err)
 			}
 
-			chainConfig := nodeConfig.ChainConfig
+			genesis := new(core.Genesis)
+			if err := json.Unmarshal([]byte(nodeConfig.LightEthConfig.Genesis), genesis); err != nil {
+				t.Fatal(err)
+			}
+			chainConfig := genesis.Config
 			if chainConfig.HomesteadBlock.Cmp(gethparams.MainNetHomesteadBlock) != 0 {
 				t.Fatal("invalid chainConfig.HomesteadBlock")
 			}
@@ -272,10 +282,7 @@ var loadConfigTestCases = []struct {
 			"Name": "TestStatusNode",
 			"WSPort": 8546,
 			"IPCEnabled": true,
-			"WSEnabled": false,
-			"ChainConfig": {
-				"ChainId": 311
-			}
+			"WSEnabled": false
 		}`,
 		func(t *testing.T, dataDir string, nodeConfig *params.NodeConfig, err error) {
 			//nodeConfig.LightEthConfig.Genesis = nodeConfig.LightEthConfig.Genesis[:125]
@@ -284,16 +291,10 @@ var loadConfigTestCases = []struct {
 				t.Fatalf("unexpected error: %v", err)
 			}
 
-			networkId := 311
-
+			networkId := uint64(311)
 			if nodeConfig.NetworkId != networkId {
 				t.Fatalf("unexpected NetworkId, expected: %v, got: %v", networkId, nodeConfig.NetworkId)
 			}
-
-			if nodeConfig.ChainId.Int64() != int64(networkId) {
-				t.Fatalf("unexpected ChainConfig.ChainId, expected: %v, got: %v", networkId, nodeConfig.ChainId)
-			}
-
 		},
 	},
 }
@@ -314,31 +315,36 @@ func TestLoadNodeConfig(t *testing.T) {
 }
 
 func TestConfigWriteRead(t *testing.T) {
-	tmpDir, err := ioutil.TempDir(os.TempDir(), "geth-config-tests")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer os.RemoveAll(tmpDir)
+	configReadWrite := func(networkId uint64, refFile string) {
+		tmpDir, err := ioutil.TempDir(os.TempDir(), "geth-config-tests")
+		if err != nil {
+			t.Fatal(err)
+		}
+		defer os.RemoveAll(tmpDir)
 
-	nodeConfig, err := params.NewNodeConfig(tmpDir, params.TestNetworkId)
-	if err != nil {
-		t.Fatalf("cannot create new config object: %v", err)
+		nodeConfig, err := params.NewNodeConfig(tmpDir, networkId)
+		if err != nil {
+			t.Fatalf("cannot create new config object: %v", err)
+		}
+
+		if err := nodeConfig.Save(); err != nil {
+			t.Fatalf("cannot persist configuration: %v", err)
+		}
+
+		loadedConfigData, err := ioutil.ReadFile(filepath.Join(nodeConfig.DataDir, "config.json"))
+		if err != nil {
+			t.Fatalf("cannot read configuration from disk: %v", err)
+		}
+
+		refConfigData := geth.LoadFromFile(refFile)
+
+		refConfigData = strings.Replace(refConfigData, "$TMPDIR", nodeConfig.DataDir, -1)
+		refConfigData = strings.Replace(refConfigData, "$VERSION", params.Version, -1)
+		if string(loadedConfigData) != refConfigData {
+			t.Fatalf("configuration mismatch,\nexpected: %v\ngot: %v", refConfigData, string(loadedConfigData))
+		}
 	}
 
-	if err := nodeConfig.Save(); err != nil {
-		t.Fatalf("cannot persist configuration: %v", err)
-	}
-
-	loadedConfigData, err := ioutil.ReadFile(filepath.Join(nodeConfig.DataDir, "config.json"))
-	if err != nil {
-		t.Fatalf("cannot read configuration from disk: %v", err)
-	}
-
-	refConfigData := geth.LoadFromFile("testdata/config.testnet.json")
-
-	refConfigData = strings.Replace(refConfigData, "$TMPDIR", nodeConfig.DataDir, -1)
-	refConfigData = strings.Replace(refConfigData, "$VERSION", params.Version, -1)
-	if string(loadedConfigData) != refConfigData {
-		t.Fatalf("configuration mismatch,\nexpected: %v\ngot: %v", refConfigData, string(loadedConfigData))
-	}
+	configReadWrite(params.TestNetworkId, "testdata/config.testnet.json")
+	configReadWrite(params.MainNetworkId, "testdata/config.mainnet.json")
 }

geth/params/defaults.go

@@ -1,11 +1,5 @@
 package params
 
-import (
-	"math/big"
-
-	"github.com/ethereum/go-ethereum/common"
-)
-
 const (
 	// ClientIdentifier is client identifier to advertise over the network
 	ClientIdentifier = "StatusIM"
@@ -57,6 +51,9 @@ const (
 	// LogLevel defines the minimum log level to report
 	LogLevel = "INFO"
 
+	// LogToStderr defines whether logged info should also be output to os.Stderr
+	LogToStderr = true
+
 	// WhisperDataDir is directory where Whisper data is stored, relative to DataDir
 	WhisperDataDir = "wnode"
 
@@ -69,17 +66,9 @@ const (
 	// WhisperTTL is time to live for messages, in seconds
 	WhisperTTL = 120
 
+	// MainNetworkId is id of the main network
+	MainNetworkId = 1
+
 	// TestNetworkId is id of a test network
 	TestNetworkId = 3
 )
-
-// Gas price settings
-var (
-	GasPrice                = new(big.Int).Mul(big.NewInt(20), common.Shannon)  // Minimal gas price to accept for mining a transactions
-	GpoMinGasPrice          = new(big.Int).Mul(big.NewInt(20), common.Shannon)  // Minimum suggested gas price
-	GpoMaxGasPrice          = new(big.Int).Mul(big.NewInt(500), common.Shannon) // Maximum suggested gas price
-	GpoFullBlockRatio       = 80                                                // Full block threshold for gas price calculation (%)
-	GpobaseStepDown         = 10                                                // Suggested gas price base step down ratio (1/1000)
-	GpobaseStepUp           = 100                                               // Suggested gas price base step up ratio (1/1000)
-	GpobaseCorrectionFactor = 110                                               // Suggested gas price base correction factor (%)
-)

geth/params/logger.go

@@ -1,145 +1,92 @@
 package params
 
 import (
-	"bufio"
-	"fmt"
-	"io"
 	"os"
 	"path/filepath"
 	"sync"
 
-	"github.com/ethereum/go-ethereum/logger"
-	"github.com/ethereum/go-ethereum/logger/glog"
+	"github.com/ethereum/go-ethereum/log"
 )
 
 // Logger is wrapper for custom logging
 type Logger struct {
-	sync.Mutex
-	logFile  *os.File
-	observer chan string
-	started  chan struct{}
-	stopped  chan struct{}
-	stopFlag bool
+	origHandler log.Handler
+	handler     log.Handler
+	config      *NodeConfig
 }
 
-var onceStartLogger sync.Once
+var (
+	onceInitNodeLogger sync.Once
+	nodeLoggerInstance *Logger
+)
 
 // SetupLogger configs logger using parameters in config
-func SetupLogger(config *NodeConfig) (nodeLogger *Logger, err error) {
+func SetupLogger(config *NodeConfig) (*Logger, error) {
 	if !config.LogEnabled {
 		return nil, nil
 	}
 
-	nodeLogger = &Logger{
-		started: make(chan struct{}, 1),
-		stopped: make(chan struct{}, 1),
-	}
-
-	onceStartLogger.Do(func() {
-		err = nodeLogger.createAndStartLogger(config)
+	onceInitNodeLogger.Do(func() {
+		nodeLoggerInstance = &Logger{
+			config:      config,
+			origHandler: log.Root().GetHandler(),
+		}
+		nodeLoggerInstance.handler = nodeLoggerInstance.makeLogHandler(log.LvlInfo)
 	})
 
-	return
+	if err := nodeLoggerInstance.Start(); err != nil {
+		return nil, err
+	}
+
+	return nodeLoggerInstance, nil
 }
 
 // SetV allows to dynamically change log level of messages being written
 func (l *Logger) SetV(logLevel string) {
-	glog.SetV(parseLogLevel(logLevel))
+	log.Root().SetHandler(l.makeLogHandler(parseLogLevel(logLevel)))
 }
 
-// Stop marks logger as stopped, forcing to relinquish hold
-// on os.Stderr and restore it back to the original
-func (l *Logger) Stop() (stopped chan struct{}) {
-	l.Lock()
-	defer l.Unlock()
-
-	l.stopFlag = true
-	stopped = l.stopped
-	return
-}
-
-// Observe registers extra writer where logs should be written to.
-// This method is used in unit tests, and should NOT be relied upon otherwise.
-func (l *Logger) Observe(observer chan string) (started chan struct{}) {
-	l.observer = observer
-	started = l.started
-	return
-}
-
-// createAndStartLogger initializes and starts logger by replacing os.Stderr with custom writer.
-// Custom writer intercepts all requests to os.Stderr, then forwards to multiple readers, which
-// include log file and the original os.Stderr (so that logs output on screen as well)
-func (l *Logger) createAndStartLogger(config *NodeConfig) error {
-	// customize glog
-	glog.CopyStandardLogTo("INFO")
-	glog.SetToStderr(true)
-	glog.SetV(parseLogLevel(config.LogLevel))
-
-	// create log file
-	logFile, err := os.OpenFile(filepath.Join(config.DataDir, config.LogFile), os.O_CREATE|os.O_APPEND|os.O_RDWR, 0666)
-	if err != nil {
-		return err
-	}
-
-	// inject reader to pipe all writes to Stderr
-	r, w, err := os.Pipe()
-	if err != nil {
-		return err
-	}
-
-	// replace Stderr
-	origStderr := os.Stderr
-	os.Stderr = w
-	scanner := bufio.NewScanner(r)
-
-	// configure writer, send to the original os.Stderr and log file
-	logWriter := io.MultiWriter(origStderr, logFile)
-
-	go func() {
-		defer func() { // restore original Stderr
-			os.Stderr = origStderr
-			logFile.Close()
-			close(l.stopped)
-		}()
-
-		// notify observer that it can start polling (unit test, normally)
-		close(l.started)
-
-		for scanner.Scan() {
-			fmt.Fprintln(logWriter, scanner.Text())
-
-			if l.observer != nil {
-				l.observer <- scanner.Text()
-			}
-
-			// allow to restore original os.Stderr if logger is stopped
-			if l.stopFlag {
-				return
-			}
-		}
-
-		if err := scanner.Err(); err != nil {
-			fmt.Fprintf(origStderr, "error reading logs: %v\n", err)
-		}
-	}()
-
+// Start installs logger handler
+func (l *Logger) Start() error {
+	log.Root().SetHandler(l.handler)
 	return nil
 }
 
-// parseLogLevel parses string and returns logger.* constant
-func parseLogLevel(logLevel string) int {
-	switch logLevel {
-	case "ERROR":
-		return logger.Error
-	case "WARNING":
-		return logger.Warn
-	case "INFO":
-		return logger.Info
-	case "DEBUG":
-		return logger.Debug
-	case "DETAIL":
-		return logger.Detail
+// Stop replaces our handler back to the original log handler
+func (l *Logger) Stop() error {
+	log.Root().SetHandler(l.origHandler)
+	return nil
+}
+
+// makeLogHandler creates a log handler for a given level and node configuration
+func (l *Logger) makeLogHandler(lvl log.Lvl) log.Handler {
+	var handler log.Handler
+	logFilePath := filepath.Join(l.config.DataDir, l.config.LogFile)
+	if l.config.LogToStderr {
+		handler = log.MultiHandler(
+			log.LvlFilterHandler(lvl, log.StreamHandler(os.Stderr, log.TerminalFormat(true))),
+			log.LvlFilterHandler(lvl, log.Must.FileHandler(logFilePath, log.LogfmtFormat())))
+	} else {
+		handler = log.LvlFilterHandler(lvl, log.Must.FileHandler(logFilePath, log.LogfmtFormat()))
 	}
 
-	return logger.Info
+	return handler
+}
+
+// parseLogLevel parses string and returns logger.* constant
+func parseLogLevel(logLevel string) log.Lvl {
+	switch logLevel {
+	case "ERROR":
+		return log.LvlError
+	case "WARNING":
+		return log.LvlWarn
+	case "INFO":
+		return log.LvlInfo
+	case "DEBUG":
+		return log.LvlDebug
+	case "TRACE":
+		return log.LvlTrace
+	}
+
+	return log.LvlInfo
 }

geth/params/logger_test.go

@@ -1,16 +1,13 @@
 package params_test
 
 import (
-	"fmt"
 	"io/ioutil"
-	"log"
 	"os"
 	"path/filepath"
+	"strings"
 	"testing"
-	"time"
 
-	"github.com/ethereum/go-ethereum/logger"
-	"github.com/ethereum/go-ethereum/logger/glog"
+	"github.com/ethereum/go-ethereum/log"
 	"github.com/status-im/status-go/geth/params"
 )
 
@@ -19,7 +16,7 @@ func TestLogger(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	defer os.RemoveAll(tmpDir)
+	//defer os.RemoveAll(tmpDir)
 
 	nodeConfig, err := params.NewNodeConfig(tmpDir, params.TestNetworkId)
 	if err != nil {
@@ -34,6 +31,7 @@ func TestLogger(t *testing.T) {
 	}
 
 	nodeConfig.LogEnabled = true
+	nodeConfig.LogToStderr = false // just capture logs to file
 	nodeLogger, err = params.SetupLogger(nodeConfig)
 	if err != nil {
 		t.Fatal("cannot create logger object")
@@ -42,104 +40,41 @@ func TestLogger(t *testing.T) {
 		t.Fatal("logger is empty (while logs are enabled)")
 	}
 
-	logReader := make(chan string, 100)
-	loggerStarted := nodeLogger.Observe(logReader)
-	<-loggerStarted // allow logger to setup itself
-
-	expectedLogTextInLogFile := "" // aggregate log contents accross all tests
-	validateLoggerObserverText := func(observer chan string, expectedLogText string) {
-		logText := ""
-
-		select {
-		case logText = <-observer:
-			expectedLogTextInLogFile += logText + "\n"
-			logText = logText[len(logText)-len(expectedLogText):] // as logs can be prepended with glog info
-		case <-time.After(3 * time.Second):
+	validateLogText := func(expectedLogText string) {
+		logFilePath := filepath.Join(nodeConfig.DataDir, nodeConfig.LogFile)
+		logBytes, err := ioutil.ReadFile(logFilePath)
+		if err != nil {
+			panic(err)
 		}
+		logText := string(logBytes)
+		logText = strings.Trim(logText, "\n")
+		logText = logText[len(logText)-len(expectedLogText):] // as logs can be prepended with log info
 
-		if logText != expectedLogText {
-			t.Fatalf("invalid log, expected: %#v, got: %#v", expectedLogText, logText)
+		if expectedLogText != logText {
+			t.Fatalf("invalid log, expected: [%s], got: [%s]", expectedLogText, string(logText))
+		} else {
+			t.Logf("log match found, expected: [%s], got: [%s]", expectedLogText, string(logText))
 		}
 	}
 
-	loggerTestCases := []struct {
-		name     string
-		log      func()
-		validate func()
-	}{
-		{
-			"log using standard log package",
-			func() {
-				log.Println("use standard log package")
-			},
-			func() {
-				validateLoggerObserverText(logReader, "use standard log package")
-			},
-		},
-		{
-			"log using standard glog package",
-			func() {
-				glog.V(logger.Info).Infoln("use glog package")
-			},
-			func() {
-				validateLoggerObserverText(logReader, "use glog package")
-			},
-		},
-		{
-			"log using os.Stderr (write directly to it)",
-			func() {
-				fmt.Fprintln(os.Stderr, "use os.Stderr package")
-			},
-			func() {
-				validateLoggerObserverText(logReader, "use os.Stderr package")
-			},
-		},
-		{
-			"log using DEBUG log level (with appropriate level set)",
-			func() {
-				nodeLogger.SetV("DEBUG")
-				glog.V(logger.Debug).Info("logged DEBUG log level message")
-			},
-			func() {
-				validateLoggerObserverText(logReader, "logged DEBUG log level message")
-			},
-		},
-		{
-			"log using DEBUG log level (with appropriate level NOT set)",
-			func() {
-				nodeLogger.SetV("INFO")
-				glog.V(logger.Info).Info("logged INFO log level message")
-				glog.V(logger.Debug).Info("logged DEBUG log level message")
-			},
-			func() {
-				validateLoggerObserverText(logReader, "logged INFO log level message")
-			},
-		},
-	}
+	// sample log message
+	log.Info("use log package")
+	validateLogText(`msg="use log package"`)
 
-	for _, testCase := range loggerTestCases {
-		t.Log("test: " + testCase.name)
-		testCase.log()
-		testCase.validate()
-	}
+	// log using DEBUG log level (with appropriate level set)
+	nodeLogger.SetV("DEBUG")
+	log.Info("logged DEBUG log level message")
+	validateLogText(`msg="logged DEBUG log level message"`)
 
-	logFileContents, err := ioutil.ReadFile(filepath.Join(tmpDir, nodeConfig.LogFile))
-	if err != nil {
-		t.Fatalf("cannot read logs file: %v", err)
-	}
-	if string(logFileContents) != expectedLogTextInLogFile {
-		t.Fatalf("wrong content of log file, expected:\n%v\ngot:\n%v", expectedLogTextInLogFile, string(logFileContents))
-	}
+	// log using DEBUG log level (with appropriate level set)
+	nodeLogger.SetV("INFO")
+	log.Info("logged INFO log level message")
+	validateLogText(`msg="logged INFO log level message"`)
+	log.Debug("logged DEBUG log level message")
+	validateLogText(`msg="logged INFO log level message"`) // debug level message is NOT logged
 
-	go func() {
-		for i := 0; i < 10; i++ {
-			glog.Infoln("logging message: ", i)
-			time.Sleep(1 * time.Millisecond)
-		}
-	}()
+	// stop logger and see if os.Stderr and gethlog continue functioning
+	nodeLogger.Stop()
 
-	// stop logger and see if os.Stderr and glog continue functioning
-	<-nodeLogger.Stop()
-
-	glog.Infoln("logging message: this message happens after custom logger has been stopped")
+	log.Info("logging message: this message happens after custom logger has been stopped")
 }