making the ECS init log level configurable

README.md

@@ -270,7 +270,6 @@ Additionally, the following environment variable(s) can be used to configure the
 | `ECS_AGENT_APPARMOR_PROFILE` | `unconfined` | Specifies the name of the AppArmor profile to run the ecs-agent container under. This only applies to AppArmor-enabled systems, such as Ubuntu, Debian, and SUSE. If unset, defaults to the profile written out by ecs-init (ecs-agent-default). | `ecs-agent-default` |
 
 
-
 ### Persistence
 
 When you run the Amazon ECS Container Agent in production, its `datadir` should be persisted between runs of the Docker

ecs-init/config/common.go

@@ -173,7 +173,7 @@ func LogDirectory() string {
 	return directoryPrefix + "/var/log/ecs"
 }
 
-func initLogFile() string {
+func InitLogFile() string {
 	return LogDirectory() + "/ecs-init.log"
 }
 

ecs-init/ecs-init.go

@@ -18,8 +18,8 @@ import (
 	"fmt"
 	"os"
 
-	"github.com/aws/amazon-ecs-agent/ecs-init/config"
 	"github.com/aws/amazon-ecs-agent/ecs-init/engine"
+	"github.com/aws/amazon-ecs-agent/ecs-init/logger"
 	"github.com/aws/amazon-ecs-agent/ecs-init/version"
 
 	log "github.com/cihub/seelog"
@@ -37,7 +37,6 @@ const (
 )
 
 func main() {
-	defer log.Flush()
 	flag.Parse()
 	args := flag.Args()
 
@@ -46,12 +45,8 @@ func main() {
 		os.Exit(1)
 	}
 
-	logger, err := log.LoggerFromConfigAsString(config.Logger())
-	if err != nil {
-		die(err, engine.DefaultInitErrorExitCode)
-	}
-	log.ReplaceLogger(logger)
-
+	logger.Setup()
+	defer log.Flush()
 	if args[0] == VERSION {
 		err := version.PrintVersion()
 		if err != nil {

ecs-init/logger/log.go

@@ -0,0 +1,119 @@
+// Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"). You may
+// not use this file except in compliance with the License. A copy of the
+// License is located at
+//
+//	http://aws.amazon.com/apache2.0/
+//
+// or in the "license" file accompanying this file. This file is distributed
+// on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+// express or implied. See the License for the specific language governing
+// permissions and limitations under the License.
+
+package logger
+
+import (
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	conf "github.com/aws/amazon-ecs-agent/ecs-init/config"
+	"github.com/cihub/seelog"
+)
+
+const (
+	LOGLEVEL_ENV_VAR = "ECS_LOGLEVEL"
+	defaultLogLevel  = "info"
+	outputFmt        = "logfmt"
+	rollCount        = 24
+)
+
+// logLevels is the mapping from ECS_INIT_LOGLEVEL to Seelog provided levels.
+var logLevels = map[string]string{
+	"debug": "debug",
+	"info":  "info",
+	"warn":  "warn",
+	"error": "error",
+	"crit":  "critical",
+	"none":  "off",
+}
+
+type logConfig struct {
+	level        string
+	outputFormat string
+	maxRollCount int
+	lock         sync.Mutex
+}
+
+// config contains config for seelog logger
+var config *logConfig
+
+func init() {
+	config = &logConfig{
+		level:        defaultLogLevel,
+		outputFormat: outputFmt,
+		maxRollCount: rollCount,
+	}
+}
+
+// Setup sets the custom logging config
+func Setup() {
+	if logLevel := os.Getenv(LOGLEVEL_ENV_VAR); logLevel != "" {
+		SetLogLevel(logLevel)
+	}
+	if err := seelog.RegisterCustomFormatter("InitLogfmt", logfmtFormatter); err != nil {
+		seelog.Error(err)
+	}
+	reloadConfig()
+}
+
+func logfmtFormatter(params string) seelog.FormatterFunc {
+	return func(message string, level seelog.LogLevel, context seelog.LogContextInterface) interface{} {
+		return fmt.Sprintf(`level=%s time=%s msg=%q
+`, level.String(), context.CallTime().UTC().Format(time.RFC3339), message)
+	}
+}
+
+func SetLogLevel(logLevel string) {
+	parsedLevel, ok := logLevels[strings.ToLower(logLevel)]
+	if ok {
+		config.lock.Lock()
+		defer config.lock.Unlock()
+		config.level = parsedLevel
+		reloadConfig()
+	} else {
+		seelog.Error("log level mapping not found")
+	}
+}
+
+func reloadConfig() {
+	logger, err := seelog.LoggerFromConfigAsString(seelogConfig())
+	if err == nil {
+		seelog.ReplaceLogger(logger)
+	} else {
+		seelog.Error(err)
+	}
+}
+
+func seelogConfig() string {
+	c := `
+<seelog type="asyncloop" minlevel="` + config.level + `">
+	<outputs formatid="` + config.outputFormat + `">
+		<console />`
+	if conf.InitLogFile() != "" {
+		c += `
+		<rollingfile filename="` + conf.InitLogFile() + `" type="date"
+		 datepattern="2006-01-02-15" archivetype="none" maxrolls="` + strconv.Itoa(config.maxRollCount) + `" />`
+	}
+	c += `
+	</outputs>
+	<formats>
+		<format id="logfmt" format="%InitLogfmt" />
+	</formats>
+</seelog>`
+	return c
+}

ecs-init/logger/log_test.go

@@ -0,0 +1,96 @@
+// Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"). You may
+// not use this file except in compliance with the License. A copy of the
+// License is located at
+//
+//	http://aws.amazon.com/apache2.0/
+//
+// or in the "license" file accompanying this file. This file is distributed
+// on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+// express or implied. See the License for the specific language governing
+// permissions and limitations under the License.
+
+package logger
+
+import (
+	"testing"
+	"time"
+
+	conf "github.com/aws/amazon-ecs-agent/ecs-init/config"
+	"github.com/cihub/seelog"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestLogfmtFormat(t *testing.T) {
+	logfmt := logfmtFormatter("")
+	out := logfmt("This is my log message", seelog.InfoLvl, &LogContextMock{})
+	s, ok := out.(string)
+	assert.True(t, ok)
+	assert.Equal(t, `level=info time=2018-10-01T01:02:03Z msg="This is my log message"
+`, s)
+}
+
+func TestSeelogConfig(t *testing.T) {
+	config = &logConfig{
+		level:        defaultLogLevel,
+		outputFormat: outputFmt,
+		maxRollCount: 24,
+	}
+	c := seelogConfig()
+	assert.Equal(t, `
+<seelog type="asyncloop" minlevel="info">
+	<outputs formatid="logfmt">
+		<console />
+		<rollingfile filename="`+conf.InitLogFile()+`" type="date"
+		 datepattern="2006-01-02-15" archivetype="none" maxrolls="24" />
+	</outputs>
+	<formats>
+		<format id="logfmt" format="%InitLogfmt" />
+	</formats>
+</seelog>`, c)
+}
+
+type LogContextMock struct{}
+
+// Caller's function name.
+func (l *LogContextMock) Func() string {
+	return ""
+}
+
+// Caller's line number.
+func (l *LogContextMock) Line() int {
+	return 0
+}
+
+// Caller's file short path (in slashed form).
+func (l *LogContextMock) ShortPath() string {
+	return ""
+}
+
+// Caller's file full path (in slashed form).
+func (l *LogContextMock) FullPath() string {
+	return ""
+}
+
+// True if the context is correct and may be used.
+// If false, then an error in context evaluation occurred and
+// all its other data may be corrupted.
+func (l *LogContextMock) IsValid() bool {
+	return true
+}
+
+// Time when log function was called.
+func (l *LogContextMock) CallTime() time.Time {
+	return time.Date(2018, time.October, 1, 1, 2, 3, 0, time.UTC)
+}
+
+// Custom context that can be set by calling logger.SetContext
+func (l *LogContextMock) CustomContext() interface{} {
+	return map[string]string{}
+}
+
+// Caller's file name (without path).
+func (l *LogContextMock) FileName() string {
+	return "mytestmodule.go"
+}

seelog.xml

@@ -13,7 +13,7 @@ and limitations under the License.
 <seelog type="asyncloop">
 	<outputs formatid="main">
 		<console formatid="console" />
-		<rollingfile filename="` + initLogFile() + `" type="date"
+		<rollingfile filename="` + InitLogFile() + `" type="date"
 			 datepattern="2006-01-02-15" archivetype="zip" maxrolls="5" />
 	</outputs>
 	<formats>