Add custom usage template for cobra command so that usage will displa…

…y 'kubectl krew' instead of just 'krew'

.gitignore

@@ -11,6 +11,10 @@
 # Output of the go coverage tool, specifically when used with LiteIDE
 *.out
 
+# Files generated by JetBrains IDEs, e.g. IntelliJ IDEA
+.idea/
+*.iml
+
 out/
 build/
 coverage.txt

cmd/krew/cmd/root.go

@@ -19,6 +19,7 @@ import (
 	"fmt"
 	"math/rand"
 	"os"
+	"strings"
 	"time"
 
 	"github.com/fatih/color"
@@ -98,6 +99,13 @@ func init() {
 	}
 
 	paths = environment.MustGetKrewPaths()
+
+	// Cobra doesn't have a way to specify a two word command (ie. "kubectl krew"), so set a custom usage template
+	// with kubectl in it. Cobra will use this template for the root and all child commands.
+	customUsageTemplate := rootCmd.UsageTemplate()
+	customUsageTemplate = strings.ReplaceAll(customUsageTemplate, "{{.UseLine}}", "kubectl {{.UseLine}}")
+	customUsageTemplate = strings.ReplaceAll(customUsageTemplate, "{{.CommandPath}}", "kubectl {{.CommandPath}}")
+	rootCmd.SetUsageTemplate(customUsageTemplate)
 }
 
 func preRun(cmd *cobra.Command, _ []string) error {