logging: Log only for unhandled errors, remove all the debug logging. (#1652)

This patch brings in the removal of debug logging altogether, instead
we bring in the functionality of being able to trace the errors properly
pointing back to the origination of the problem.

To enable tracing you need to enable "MINIO_TRACE" set to "1" or "true"
environment variable which would print back traces whenever there is an
error which is unhandled or at the handler layer.

By default this tracing is turned off and only user level logging is
provided.

main.go

@@ -20,15 +20,11 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
-	"runtime"
 	"sort"
-	"strconv"
 
-	"github.com/dustin/go-humanize"
 	"github.com/minio/cli"
 	"github.com/minio/mc/pkg/console"
 	"github.com/minio/minio/pkg/probe"
-	"github.com/olekukonko/ts"
 	"github.com/pkg/profile"
 )
 
@@ -60,10 +56,7 @@ FLAGS:
   {{end}}{{end}}
 VERSION:
   ` + minioVersion +
-	`{{ "\n"}}{{range $key, $value := ExtraInfo}}
-{{$key}}:
-  {{$value}}
-{{end}}`
+	`{{ "\n"}}`
 
 // init - check the environment before main starts
 func init() {
@@ -92,32 +85,6 @@ func enableLoggers() {
 	// Add your logger here.
 }
 
-// Tries to get os/arch/platform specific information
-// Returns a map of current os/arch/platform/memstats
-func getSystemData() map[string]string {
-	host, err := os.Hostname()
-	if err != nil {
-		host = ""
-	}
-	memstats := &runtime.MemStats{}
-	runtime.ReadMemStats(memstats)
-	mem := fmt.Sprintf("Used: %s | Allocated: %s | Used-Heap: %s | Allocated-Heap: %s",
-		humanize.Bytes(memstats.Alloc),
-		humanize.Bytes(memstats.TotalAlloc),
-		humanize.Bytes(memstats.HeapAlloc),
-		humanize.Bytes(memstats.HeapSys))
-	platform := fmt.Sprintf("Host: %s | OS: %s | Arch: %s",
-		host,
-		runtime.GOOS,
-		runtime.GOARCH)
-	goruntime := fmt.Sprintf("Version: %s | CPUs: %s", runtime.Version(), strconv.Itoa(runtime.NumCPU()))
-	return map[string]string{
-		"PLATFORM": platform,
-		"RUNTIME":  goruntime,
-		"MEM":      mem,
-	}
-}
-
 func findClosestCommands(command string) []string {
 	var closestCommands []string
 	for _, value := range commandsTree.PrefixMatch(command) {
@@ -195,15 +162,16 @@ func main() {
 		defer profile.Start(profile.BlockProfile, profile.ProfilePath(mustGetProfilePath())).Stop()
 	}
 
+	// Set global trace flag.
+	trace := os.Getenv("MINIO_TRACE")
+	globalTrace = trace == "1"
+
 	probe.Init() // Set project's root source path.
 	probe.SetAppInfo("Release-Tag", minioReleaseTag)
 	probe.SetAppInfo("Commit-ID", minioShortCommitID)
 
 	app := registerApp()
 	app.Before = func(c *cli.Context) error {
-		// Set global flags.
-		setGlobalsFromContext(c)
-
 		// Sets new config folder.
 		setGlobalConfigPath(c.GlobalString("config-dir"))
 
@@ -215,7 +183,7 @@ func main() {
 
 		// Initialize config.
 		err := initConfig()
-		fatalIf(err, "Unable to initialize minio config.", nil)
+		fatalIf(err, "Unable to initialize minio config.")
 
 		// Enable all loggers by now.
 		enableLoggers()
@@ -223,6 +191,9 @@ func main() {
 		// Initialize name space lock.
 		initNSLock()
 
+		// Set global quiet flag.
+		globalQuiet = c.Bool("quiet") || c.GlobalBool("quiet")
+
 		// Do not print update messages, if quiet flag is set.
 		if !globalQuiet {
 			// Do not print any errors in release update function.
@@ -236,16 +207,6 @@ func main() {
 		// Return here.
 		return nil
 	}
-	app.ExtraInfo = func() map[string]string {
-		if _, e := ts.GetSize(); e != nil {
-			globalQuiet = true
-		}
-		// Enable if debug is enabled.
-		if globalDebug {
-			return getSystemData()
-		}
-		return make(map[string]string)
-	}
 	// Run the app - exit on error.
 	app.RunAndExitOnError()
 }