TUN-7135: Add cloudflared tail

cmd/cloudflared/cliutil/logger.go

@@ -0,0 +1,51 @@
+package cliutil
+
+import (
+	"github.com/urfave/cli/v2"
+	"github.com/urfave/cli/v2/altsrc"
+
+	"github.com/cloudflare/cloudflared/logger"
+)
+
+var (
+	debugLevelWarning = "At debug level cloudflared will log request URL, method, protocol, content length, as well as, all request and response headers. " +
+		"This can expose sensitive information in your logs."
+)
+
+func ConfigureLoggingFlags(shouldHide bool) []cli.Flag {
+	return []cli.Flag{
+		altsrc.NewStringFlag(&cli.StringFlag{
+			Name:    logger.LogLevelFlag,
+			Value:   "info",
+			Usage:   "Application logging level {debug, info, warn, error, fatal}. " + debugLevelWarning,
+			EnvVars: []string{"TUNNEL_LOGLEVEL"},
+			Hidden:  shouldHide,
+		}),
+		altsrc.NewStringFlag(&cli.StringFlag{
+			Name:    logger.LogTransportLevelFlag,
+			Aliases: []string{"proto-loglevel"}, // This flag used to be called proto-loglevel
+			Value:   "info",
+			Usage:   "Transport logging level(previously called protocol logging level) {debug, info, warn, error, fatal}",
+			EnvVars: []string{"TUNNEL_PROTO_LOGLEVEL", "TUNNEL_TRANSPORT_LOGLEVEL"},
+			Hidden:  shouldHide,
+		}),
+		altsrc.NewStringFlag(&cli.StringFlag{
+			Name:    logger.LogFileFlag,
+			Usage:   "Save application log to this file for reporting issues.",
+			EnvVars: []string{"TUNNEL_LOGFILE"},
+			Hidden:  shouldHide,
+		}),
+		altsrc.NewStringFlag(&cli.StringFlag{
+			Name:    logger.LogDirectoryFlag,
+			Usage:   "Save application log to this directory for reporting issues.",
+			EnvVars: []string{"TUNNEL_LOGDIRECTORY"},
+			Hidden:  shouldHide,
+		}),
+		altsrc.NewStringFlag(&cli.StringFlag{
+			Name:    "trace-output",
+			Usage:   "Name of trace output file, generated when cloudflared stops.",
+			EnvVars: []string{"TUNNEL_TRACE_OUTPUT"},
+			Hidden:  shouldHide,
+		}),
+	}
+}