plugins: Load plugins on windows

plugins/shared/loader/init.go

@@ -6,6 +6,7 @@ import (
 	"os/exec"
 	"path/filepath"
 	"sort"
+	"runtime"
 
 	multierror "github.com/hashicorp/go-multierror"
 	plugin "github.com/hashicorp/go-plugin"
@@ -250,10 +251,15 @@ func (l *PluginLoader) scan() ([]os.FileInfo, error) {
 			continue
 		}
 
-		// Check if it is executable by anyone
-		if s.Mode().Perm()&0111 == 0 {
-			l.logger.Debug("skipping un-executable file in plugin folder", "file", f)
-			continue
+		// Check if it is executable by anyone. On windows, an executable is any file with any
+		// extension and the file begins with MZ, however, there is no easy way for us to
+		// actually validate the executability of a file, so here we skip executability checks
+		// for windows systems.
+		if runtime.GOOS != "windows" {
+			if s.Mode().Perm()&0111 == 0 {
+				l.logger.Debug("skipping un-executable file in plugin folder", "file", f)
+				continue
+			}
 		}
 		plugins = append(plugins, s)
 	}

plugins/shared/loader/loader_test.go

@@ -8,6 +8,7 @@ import (
 	"sort"
 	"strings"
 	"testing"
+	"runtime"
 
 	log "github.com/hashicorp/go-hclog"
 	version "github.com/hashicorp/go-version"
@@ -55,8 +56,12 @@ func newHarness(t *testing.T, plugins []string) *harness {
 		t.Fatalf("failed to get self executable path: %v", err)
 	}
 
+	exeSuffix := ""
+	if runtime.GOOS == "windows" {
+		exeSuffix = ".exe"
+	}
 	for _, p := range plugins {
-		dest := filepath.Join(h.tmpDir, p)
+		dest := strings.Join([]string{filepath.Join(h.tmpDir, p), exeSuffix}, "")
 		if err := copyFile(selfExe, dest); err != nil {
 			t.Fatalf("failed to copy file: %v", err)
 		}
@@ -1217,6 +1222,9 @@ func TestPluginLoader_Bad_Executable(t *testing.T) {
 
 // Test that we skip directories, non-executables and follow symlinks
 func TestPluginLoader_External_SkipBadFiles(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		t.Skip("Windows currently does not skip non exe files")
+	}
 	t.Parallel()
 	require := require.New(t)