Pull request 1879: nextapi-opts

Merge in DNS/adguard-home from nextapi-opts to master

Squashed commit of the following:

commit 01f27e374785f47f41470126ddc17cf447e84dd7
Merge: 17d3b06e0 371261b2c
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Tue Jun 20 13:43:08 2023 +0300

    Merge branch 'master' into nextapi-opts

commit 17d3b06e0551908b06be67233181ce4067b6c1cc
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Tue Jun 20 13:15:31 2023 +0300

    next: imp chlog

commit 19d5ea9db0ee077c55c9f1d54a07a3c6b56b4e2e
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Tue Jun 20 12:58:48 2023 +0300

    cmd: typo

commit 082ad5b5fc634a1533127e428680ccf55c0811ab
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Mon Jun 19 22:49:16 2023 +0300

    cmd: imp api, docs, names

commit a49b3cbcc591f36530306c2e08cf1ea7dc8f6d30
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Mon Jun 19 17:13:50 2023 +0300

    next/cmd: add opt parsing

internal/next/cmd/log.go

@@ -0,0 +1,39 @@
+package cmd
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/AdguardTeam/AdGuardHome/internal/aghos"
+	"github.com/AdguardTeam/golibs/log"
+)
+
+// syslogServiceName is the name of the AdGuard Home service used for writing
+// logs to the system log.
+const syslogServiceName = "AdGuardHome"
+
+// setLog sets up the text logging.
+//
+// TODO(a.garipov): Add parameters from configuration file.
+func setLog(opts *options) (err error) {
+	switch opts.confFile {
+	case "stdout":
+		log.SetOutput(os.Stdout)
+	case "stderr":
+		log.SetOutput(os.Stderr)
+	case "syslog":
+		err = aghos.ConfigureSyslog(syslogServiceName)
+		if err != nil {
+			return fmt.Errorf("initializing syslog: %w", err)
+		}
+	default:
+		// TODO(a.garipov): Use the path.
+	}
+
+	if opts.verbose {
+		log.SetLevel(log.DEBUG)
+		log.Debug("verbose logging enabled")
+	}
+
+	return nil
+}