refactor: generate plugin executors

internal/build/plugins.go

@@ -0,0 +1,125 @@
+// ALR - Any Linux Repository
+// Copyright (C) 2025 The ALR Authors
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package build
+
+import (
+	"fmt"
+	"log/slog"
+	"os"
+	"os/exec"
+	"strings"
+	"sync"
+
+	"github.com/hashicorp/go-plugin"
+
+	"gitea.plemya-x.ru/Plemya-x/ALR/internal/logger"
+)
+
+var pluginMap = map[string]plugin.Plugin{
+	"script-executor": &ScriptExecutorPlugin{},
+	"installer":       &InstallerExecutorPlugin{},
+}
+
+var HandshakeConfig = plugin.HandshakeConfig{
+	ProtocolVersion:  1,
+	MagicCookieKey:   "ALR_PLUGIN",
+	MagicCookieValue: "-",
+}
+
+func setCommonCmdEnv(cmd *exec.Cmd) {
+	cmd.Env = []string{
+		"HOME=/var/cache/alr",
+		"LOGNAME=alr",
+		"USER=alr",
+		"PATH=/usr/bin:/bin:/usr/local/bin",
+	}
+	for _, env := range os.Environ() {
+		if strings.HasPrefix(env, "LANG=") ||
+			strings.HasPrefix(env, "LANGUAGE=") ||
+			strings.HasPrefix(env, "LC_") ||
+			strings.HasPrefix(env, "ALR_LOG_LEVEL=") {
+			cmd.Env = append(cmd.Env, env)
+		}
+	}
+}
+
+func GetSafeInstaller() (InstallerExecutor, func(), error) {
+	return getSafeExecutor[InstallerExecutor]("_internal-installer", "installer")
+}
+
+func GetSafeScriptExecutor() (ScriptExecutor, func(), error) {
+	return getSafeExecutor[ScriptExecutor]("_internal-safe-script-executor", "script-executor")
+}
+
+func getSafeExecutor[T any](subCommand, pluginName string) (T, func(), error) {
+	var err error
+
+	executable, err := os.Executable()
+	if err != nil {
+		var zero T
+		return zero, nil, err
+	}
+
+	cmd := exec.Command(executable, subCommand)
+	setCommonCmdEnv(cmd)
+
+	client := plugin.NewClient(&plugin.ClientConfig{
+		HandshakeConfig: HandshakeConfig,
+		Plugins:         pluginMap,
+		Cmd:             cmd,
+		Logger:          logger.GetHCLoggerAdapter(),
+		SkipHostEnv:     true,
+		UnixSocketConfig: &plugin.UnixSocketConfig{
+			Group: "alr",
+		},
+		SyncStderr: os.Stderr,
+	})
+	rpcClient, err := client.Client()
+	if err != nil {
+		var zero T
+		return zero, nil, err
+	}
+
+	var cleanupOnce sync.Once
+	cleanup := func() {
+		cleanupOnce.Do(func() {
+			client.Kill()
+		})
+	}
+
+	defer func() {
+		if err != nil {
+			slog.Debug("close executor")
+			cleanup()
+		}
+	}()
+
+	raw, err := rpcClient.Dispense(pluginName)
+	if err != nil {
+		var zero T
+		return zero, nil, err
+	}
+
+	executor, ok := raw.(T)
+	if !ok {
+		var zero T
+		err = fmt.Errorf("dispensed object is not a %T (got %T)", zero, raw)
+		return zero, nil, err
+	}
+
+	return executor, cleanup, nil
+}