Initial commit

pkg/distro/osrelease.go

@@ -0,0 +1,118 @@
+/*
+ * LURE - Linux User REpository
+ * Copyright (C) 2023 Elara Musayelyan
+ *
+ * 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 distro
+
+import (
+	"context"
+	"os"
+	"strings"
+
+	"lure.sh/lure/internal/shutils/handlers"
+	"mvdan.cc/sh/v3/expand"
+	"mvdan.cc/sh/v3/interp"
+	"mvdan.cc/sh/v3/syntax"
+)
+
+// OSRelease contains information from an os-release file
+type OSRelease struct {
+	Name             string
+	PrettyName       string
+	ID               string
+	Like             []string
+	VersionID        string
+	ANSIColor        string
+	HomeURL          string
+	DocumentationURL string
+	SupportURL       string
+	BugReportURL     string
+	Logo             string
+}
+
+var parsed *OSRelease
+
+// OSReleaseName returns a struct parsed from the system's os-release
+// file. It checks /etc/os-release as well as /usr/lib/os-release.
+// The first time it's called, it'll parse the os-release file.
+// Subsequent calls will return the same value.
+func ParseOSRelease(ctx context.Context) (*OSRelease, error) {
+	if parsed != nil {
+		return parsed, nil
+	}
+
+	fl, err := os.Open("/usr/lib/os-release")
+	if err != nil {
+		fl, err = os.Open("/etc/os-release")
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	file, err := syntax.NewParser().Parse(fl, "/usr/lib/os-release")
+	if err != nil {
+		return nil, err
+	}
+
+	fl.Close()
+
+	// Create new shell interpreter with nop open, exec, readdir, and stat handlers
+	// as well as no environment variables in order to prevent vulnerabilities
+	// caused by changing the os-release file.
+	runner, err := interp.New(
+		interp.OpenHandler(handlers.NopOpen),
+		interp.ExecHandler(handlers.NopExec),
+		interp.ReadDirHandler(handlers.NopReadDir),
+		interp.StatHandler(handlers.NopStat),
+		interp.Env(expand.ListEnviron()),
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	err = runner.Run(ctx, file)
+	if err != nil {
+		return nil, err
+	}
+
+	out := &OSRelease{
+		Name:             runner.Vars["NAME"].Str,
+		PrettyName:       runner.Vars["PRETTY_NAME"].Str,
+		ID:               runner.Vars["ID"].Str,
+		VersionID:        runner.Vars["VERSION_ID"].Str,
+		ANSIColor:        runner.Vars["ANSI_COLOR"].Str,
+		HomeURL:          runner.Vars["HOME_URL"].Str,
+		DocumentationURL: runner.Vars["DOCUMENTATION_URL"].Str,
+		SupportURL:       runner.Vars["SUPPORT_URL"].Str,
+		BugReportURL:     runner.Vars["BUG_REPORT_URL"].Str,
+		Logo:             runner.Vars["LOGO"].Str,
+	}
+
+	distroUpdated := false
+	if distID, ok := os.LookupEnv("LURE_DISTRO"); ok {
+		out.ID = distID
+	}
+
+	if distLike, ok := os.LookupEnv("LURE_DISTRO_LIKE"); ok {
+		out.Like = strings.Split(distLike, " ")
+	} else if runner.Vars["ID_LIKE"].IsSet() && !distroUpdated {
+		out.Like = strings.Split(runner.Vars["ID_LIKE"].Str, " ")
+	}
+
+	parsed = out
+	return out, nil
+}