improve context and namespace options insertion

main/kubectl.go

@@ -2,14 +2,19 @@ package main
 
 import (
 	"bufio"
+	"bytes"
 	"fmt"
 	"github.com/fatih/color"
 	"io"
 	"os"
 	"os/exec"
 	"os/signal"
+	"regexp"
 	"syscall"
-	"bytes"
+)
+
+var (
+	cmdPattern   *regexp.Regexp
 )
 
 func sh(shell string) error {
@@ -85,7 +90,31 @@ func shHandler(shell string, outputHandler func(string)) error {
 }
 
 func kubectl(cmd string) string {
-	buffer := bytes.NewBufferString("kubectl")
+	// Kubectl plugins are only invoked only if all arguments are specified
+	// after the command name itself.
+	//   kubectl foo --namespace=foo # works
+	//   kubectl --namespace=foo foo # fails
+	// https://kubernetes.io/docs/tasks/extend-kubectl/kubectl-plugins/
+	//
+	// The `cmd` given can contain a very complex bash input. Instead of parsing it as a whole,
+	// we will find the first control character and place the arguments just before it.
+	//
+	// This fails on some edge case inputs, such as `foo bar=z`, but currently this syntax always
+	// takes an option such as `get pods -l foo=bar`, so the `-l` would be parsed first.
+
+	if cmdPattern == nil {
+		cmdPattern = regexp.MustCompile(`[^\w\s]`)
+	}
+
+	splitAt := cmdPattern.FindStringIndex(cmd)
+	if splitAt == nil {
+		splitAt = []int{len(cmd), len(cmd)}
+	}
+	cmdA := cmd[:splitAt[0]]
+	cmdB := cmd[splitAt[0]:]
+
+	buffer := bytes.NewBufferString("kubectl ")
+	buffer.WriteString(cmdA)
 	if context != "" {
 		buffer.WriteString(" --context=")
 		buffer.WriteString(context)
@@ -95,6 +124,6 @@ func kubectl(cmd string) string {
 		buffer.WriteString(namespace)
 	}
 	buffer.WriteString(" ")
-	buffer.WriteString(cmd)
+	buffer.WriteString(cmdB)
 	return buffer.String()
 }