WIP on pluggable auth stuff

Author: Brian McCallister

pkg/plugin/plug.sh

@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+
+out="$(echo $1 | base64 -D)"
+
+echo "meow $out" >&2

pkg/plugin/plugin.go

@@ -0,0 +1,36 @@
+package plugin
+
+import (
+	"bytes"
+	"encoding/base64"
+	"os"
+	"os/exec"
+)
+
+// Plugins work by passing in values on the command line, serialized using base64
+// and reading responses out on stderr.
+// This leaves stdin/stdout available for interaction by the user, to
+// enter credentials or such
+
+// Run runs the plugin
+func Run(input []byte, plugin ...string) ([]byte, error) {
+	c := plugin[0]
+	args := plugin[1:]
+
+	in := base64.StdEncoding.EncodeToString(input)
+
+	args = append(args, in)
+
+	cmd := exec.Command(c, args...)
+	var stderr bytes.Buffer
+	cmd.Stderr = &stderr
+
+	cmd.Stdout = os.Stdout
+	cmd.Stdin = os.Stdin
+
+	err := cmd.Run()
+	if err != nil {
+		return nil, err
+	}
+	return stderr.Bytes(), nil
+}

pkg/plugin/plugin_test.go

@@ -0,0 +1,29 @@
+package plugin_test
+
+import (
+	"math/rand"
+	"testing"
+
+	"github.com/brianm/epithet/pkg/plugin"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestPlugin_BigInput(t *testing.T) {
+	in := randStringBytes(8192)
+	out, err := plugin.Run([]byte(in), "./plug.sh")
+	require.NoError(t, err)
+
+	assert.Contains(t, string(out), in)
+	assert.Contains(t, string(out), "meow")
+}
+
+const letterBytes = "abcdefghijklmnopqrstuvwxyz ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+
+func randStringBytes(n int) string {
+	b := make([]byte, n)
+	for i := range b {
+		b[i] = letterBytes[rand.Intn(len(letterBytes))]
+	}
+	return string(b)
+}