Set the default log level for Agent to INFO and raise it to DEBUG if dump-logs=true is provided (#373)

* Set the default log level for Agent to `INFO` and change it to `DEBUG` if `dump-logs=true` is provided

* Remove `Trace` method and replace its calls with `Debug`

* Export logging levels from `logger` by defining functions

* Revert "Export logging levels from `logger` by defining functions"

This reverts commit e554e40f4a.

* Run `go mod tidy` on agent

* Define a method named `determineLogLevel`

agent/main.go

@@ -22,6 +22,7 @@ import (
 	"github.com/gin-contrib/static"
 	"github.com/gin-gonic/gin"
 	"github.com/gorilla/websocket"
+	"github.com/op/go-logging"
 	"github.com/up9inc/mizu/shared"
 	"github.com/up9inc/mizu/shared/logger"
 	"github.com/up9inc/mizu/tap"
@@ -40,7 +41,8 @@ var extensions []*tapApi.Extension             // global
 var extensionsMap map[string]*tapApi.Extension // global
 
 func main() {
-	logger.InitLoggerStderrOnly()
+	logLevel := determineLogLevel()
+	logger.InitLoggerStderrOnly(logLevel)
 	flag.Parse()
 	loadExtensions()
 
@@ -303,3 +305,11 @@ func getSyncEntriesConfig() *shared.SyncEntriesConfig {
 
 	return syncEntriesConfig
 }
+
+func determineLogLevel() (logLevel logging.Level) {
+	logLevel = logging.INFO
+	if os.Getenv(shared.DebugModeEnvVar) == "1" {
+		logLevel = logging.DEBUG
+	}
+	return
+}