GenerateScript should not return encoded script (#1397)

followup to #1395

pipeline/backend/local/local.go

@@ -16,18 +16,31 @@ package local
 
 import (
 	"context"
-	"encoding/base64"
+	"fmt"
 	"io"
 	"os"
 	"os/exec"
 	"strings"
 
-	"github.com/woodpecker-ci/woodpecker/pipeline/backend/common"
+	"github.com/alessio/shellescape"
+	"golang.org/x/exp/slices"
+
 	"github.com/woodpecker-ci/woodpecker/pipeline/backend/types"
 	"github.com/woodpecker-ci/woodpecker/shared/constant"
 )
 
+// notAllowedEnvVarOverwrites are all env vars that can not be overwritten by step config
+var notAllowedEnvVarOverwrites = []string{
+	"CI_NETRC_MACHINE",
+	"CI_NETRC_USERNAME",
+	"CI_NETRC_PASSWORD",
+	"CI_SCRIPT",
+	"HOME",
+	"SHELL",
+}
+
 type local struct {
+	// TODO: make cmd a cmd list to itterate over, the hard part is to have a common ReadCloser
 	cmd        *exec.Cmd
 	output     io.ReadCloser
 	workingdir string
@@ -65,7 +78,8 @@ func (e *local) Exec(ctx context.Context, step *types.Step) error {
 	// Get environment variables
 	env := os.Environ()
 	for a, b := range step.Environment {
-		if a != "HOME" && a != "SHELL" { // Don't override $HOME and $SHELL
+		// append allowed env vars to command env
+		if !slices.Contains(notAllowedEnvVarOverwrites, a) {
 			env = append(env, a+"="+b)
 		}
 	}
@@ -73,6 +87,8 @@ func (e *local) Exec(ctx context.Context, step *types.Step) error {
 	var command []string
 	if step.Image == constant.DefaultCloneImage {
 		// Default clone step
+		// TODO: creat tmp HOME and insert netrc
+		// TODO: download plugin-git binary if not exist
 		env = append(env, "CI_WORKSPACE="+e.workingdir+"/"+step.Environment["CI_REPO"])
 		command = append(command, "plugin-git")
 	} else {
@@ -81,10 +97,14 @@ func (e *local) Exec(ctx context.Context, step *types.Step) error {
 		command = append(command, "-c")
 
 		// TODO: use commands directly
-		script, _ := base64.StdEncoding.DecodeString(common.GenerateScript(step.Commands))
-		scriptStr := string(script)
+		script := ""
+		for _, cmd := range step.Commands {
+			script += fmt.Sprintf("echo + %s\n%s\n\n", shellescape.Quote(cmd), cmd)
+		}
+		script = strings.TrimSpace(script)
+
 		// Deleting the initial lines removes netrc support but adds compatibility for more shells like fish
-		command = append(command, scriptStr[strings.Index(scriptStr, "\n\n")+2:])
+		command = append(command, script)
 	}
 
 	// Prepare command