jpictl: introduce log verbosity flag

Signed-off-by: Nagy Károly Gábriel <k@jpi.io>

cmd/jpictl/main.go

@@ -2,6 +2,8 @@
 package main
 
 import (
+	"darvaza.org/sidecar/pkg/logger/zerolog"
+	"darvaza.org/slog"
 	"github.com/spf13/cobra"
 )
 
@@ -10,13 +12,29 @@ const (
 	CmdName = "jpictl"
 )
 
-var rootCmd = &cobra.Command{
-	Use:   CmdName,
-	Short: "control tool for jpi.cloud",
-}
+var (
+	log       = zerolog.New(nil, slog.Error)
+	verbosity int
+	rootCmd   = &cobra.Command{
+		Use:   CmdName,
+		Short: "control tool for jpi.cloud",
+	}
+)
 
 func main() {
 	if err := rootCmd.Execute(); err != nil {
 		fatal(err, "")
 	}
 }
+
+func init() {
+	rootCmd.PersistentFlags().CountVarP(&verbosity, "verbosity", "v", "increase the verbosity level to Warn, Info or Debug")
+}
+
+func setVerbosity(_ *cobra.Command, _ []string) {
+	desired := int8(slog.Error) + int8(verbosity)
+	if desired > 6 {
+		desired = 6
+	}
+	log = log.WithLevel(slog.LogLevel(desired))
+}