Turn on SilenceErrors and SilenceUsage to prevent Cobra from messing up the stderr output

Signed-off-by: Richard Wall <[email protected]>

Author: wallrj

cmd/root.go

@@ -8,6 +8,8 @@ import (
 	"github.com/jetstack/preflight/pkg/logs"
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
+
+	"github.com/jetstack/preflight/pkg/logs"
 )
 
 // rootCmd represents the base command when called without any subcommands
@@ -21,6 +23,14 @@ Preflight checks are bundled into Packages`,
 	PersistentPreRun: func(cmd *cobra.Command, args []string) {
 		logs.Initialize()
 	},
+	// SilenceErrors and SilenceUsage prevents this command or any sub-command
+	// from printing arbitrary text to stderr.
+	// Why? To ensure that each line of output can be parsed as a single message
+	// for consumption by logging agents such as fluentd.
+	// Usage information is still available on stdout with the `-h` and `--help`
+	// flags.
+	SilenceErrors: true,
+	SilenceUsage:  true,
 }
 
 func init() {