build(prebuild): add new prebuild command.

Fix #146, #136

pkg/util/os.go

@@ -0,0 +1,47 @@
+// apparmor.d - Full set of apparmor profiles
+// Copyright (C) 2023 Alexandre Pujol <alexandre@pujol.io>
+// SPDX-License-Identifier: GPL-2.0-only
+
+package util
+
+import (
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/arduino/go-paths-helper"
+)
+
+var osReleaseFile = "/etc/os-release"
+
+var firstPartyDists = []string{"arch", "debian", "ubuntu", "opensuse", "whonix"}
+
+func GetSupportedDistribution() (string, error) {
+	dist, present := os.LookupEnv("DISTRIBUTION")
+	if present {
+		return dist, nil
+	}
+
+	lines, err := paths.New(osReleaseFile).ReadFileAsLines()
+	if err != nil {
+		return "", err
+	}
+
+	id := ""
+	id_like := ""
+	for _, line := range lines {
+		item := strings.Split(line, "=")
+		if item[0] == "ID" {
+			id = strings.Split(strings.Trim(item[1], "\""), " ")[0]
+		} else if item[0] == "ID_LIKE" {
+			id_like = strings.Split(strings.Trim(item[1], "\""), " ")[0]
+		}
+	}
+
+	if InSlice(id, firstPartyDists) {
+		return id, nil
+	} else if InSlice(id_like, firstPartyDists) {
+		return id_like, nil
+	}
+	return id, fmt.Errorf("%s is not a supported distribution", id)
+}