Pull request 2587: AGDNS-3681-improve-ossvc-code

Squashed commit of the following:

commit f15603569d921e048ced6539b5c2c05511a2f617
Author: Maksim Kazantsev <m.kazantsev@adguard.com>
Date:   Wed Feb 18 14:49:27 2026 +0300

    ossvc: replace !windows with unix;

commit 364291f76a24bc0f5cdb390596fd96072462f73b
Author: Maksim Kazantsev <m.kazantsev@adguard.com>
Date:   Wed Feb 18 14:42:11 2026 +0300

    ossvc: fix comment;

commit 068286ff10b8670c10d82ea812b763be4083bec4
Author: Maksim Kazantsev <m.kazantsev@adguard.com>
Date:   Wed Feb 18 14:29:02 2026 +0300

    ossvc: rm named return error value;

commit 43f966c41f6785cbe9334ca67061f4d5ba2e1a8e
Author: Maksim Kazantsev <m.kazantsev@adguard.com>
Date:   Wed Feb 18 14:26:57 2026 +0300

    ossvc: return one general Reload method; add several unexported implementation of the reload for each OS; upd docs;

commit 406434a91f9fb2683b3d0783cb5eec59d641948e
Author: Maksim Kazantsev <m.kazantsev@adguard.com>
Date:   Wed Feb 18 14:11:06 2026 +0300

    ossvcs: add docs for the windows impl of Reload; upd docs for the unix impl of Reload; rm receiver name;

commit 4c1b8c05060517d00347b03d1fc97a85edd86aaa
Author: Maksim Kazantsev <m.kazantsev@adguard.com>
Date:   Wed Feb 18 13:47:12 2026 +0300

    ossvc: decrease cognitive complexity in Reload method; mk different impls for Reload method on Windows and UNIX operating systems;

commit 088828a7ae64d930ca253a1c7deee8841b7f93f1
Author: Maksim Kazantsev <maksimkazantsev.job.it@gmail.com>
Date:   Wed Feb 18 11:42:55 2026 +0300

    make: add ossvc to lists of linted packages;

commit 4aea083cbd7753e452adf8dfa6c1016e64a95d59
Author: Maksim Kazantsev <maksimkazantsev.job.it@gmail.com>
Date:   Tue Feb 17 19:52:08 2026 +0300

    make: add ossvc package to the list of packages;

internal/ossvc/defaultmanager.go

@@ -1,15 +1,12 @@
 package ossvc
 
 import (
-	"bytes"
 	"context"
 	"fmt"
 	"log/slog"
 	"os"
 	"path/filepath"
 	"runtime"
-	"strconv"
-	"syscall"
 
 	"github.com/AdguardTeam/AdGuardHome/internal/aghos"
 	"github.com/AdguardTeam/golibs/errors"
@@ -123,51 +120,8 @@ func (m *manager) Status(ctx context.Context, name ServiceName) (status Status,
 var _ ReloadManager = (*manager)(nil)
 
 // Reload implements the [ReloadManager] interface for *manager.
-//
-// TODO(e.burkov):  On Windows just don't implement this interface.
 func (m *manager) Reload(ctx context.Context, name ServiceName) (err error) {
-	if runtime.GOOS == "windows" {
-		return errors.ErrUnsupported
-	}
-
-	nameStr := string(name)
-
-	var pid int
-	pidFile := filepath.Join("/var", "run", nameStr+".pid")
-	data, err := os.ReadFile(pidFile)
-	if err != nil {
-		if !errors.Is(err, os.ErrNotExist) {
-			return fmt.Errorf("reading service pid file: %w", err)
-		}
-
-		pid, err = aghos.PIDByCommand(ctx, m.logger, nameStr, os.Getpid())
-		if err != nil {
-			return fmt.Errorf("finding process: %w", err)
-		}
-	} else {
-		parts := bytes.SplitN(data, []byte("\n"), 2)
-		if len(parts) == 0 {
-			return fmt.Errorf("parsing %q: %w", pidFile, errors.ErrEmptyValue)
-		}
-
-		pidStr := string(bytes.TrimSpace(parts[0]))
-		pid, err = strconv.Atoi(pidStr)
-		if err != nil {
-			return fmt.Errorf("parsing pid from %q: %w", pidFile, err)
-		}
-	}
-
-	proc, err := os.FindProcess(pid)
-	if err != nil {
-		return fmt.Errorf("finding process with pid %d: %w", pid, err)
-	}
-
-	err = proc.Signal(syscall.SIGHUP)
-	if err != nil {
-		return fmt.Errorf("sending sighup to process with pid %d: %w", pid, err)
-	}
-
-	return nil
+	return m.reload(ctx, name)
 }
 
 // install installs the service in the service manager.
@@ -364,7 +318,7 @@ func (m *manager) runInitdCommand(
 }
 
 // emptyInterface is an empty implementation of the [service.Interface], as the
-// actual implementation is onlyy needed for the [service.Service.Run] method.
+// actual implementation is only needed for the [service.Service.Run] method.
 type emptyInterface struct{}
 
 // type check

internal/ossvc/manager_unix.go

@@ -0,0 +1,61 @@
+//go:build unix
+
+package ossvc
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strconv"
+	"syscall"
+
+	"github.com/AdguardTeam/AdGuardHome/internal/aghos"
+	"github.com/AdguardTeam/golibs/errors"
+)
+
+// reload is a UNIX platform implementation for the Reload method of
+// [ReloadManager] interface for *manager.
+func (m *manager) reload(ctx context.Context, name ServiceName) (err error) {
+	nameStr := string(name)
+
+	var pid int
+	pidFile := filepath.Join("/var", "run", nameStr+".pid")
+	// #nosec CWE-22 -- The name of the variable is always predictable, it is a
+	// constant.
+	data, err := os.ReadFile(pidFile)
+	if err != nil {
+		if !errors.Is(err, os.ErrNotExist) {
+			return fmt.Errorf("reading service pid file: %w", err)
+		}
+
+		pid, err = aghos.PIDByCommand(ctx, m.logger, nameStr, os.Getpid())
+		if err != nil {
+			return fmt.Errorf("finding process: %w", err)
+		}
+	} else {
+		parts := bytes.SplitN(data, []byte("\n"), 2)
+		if len(parts) == 0 {
+			return fmt.Errorf("parsing %q: %w", pidFile, errors.ErrEmptyValue)
+		}
+
+		pidStr := string(bytes.TrimSpace(parts[0]))
+		pid, err = strconv.Atoi(pidStr)
+		if err != nil {
+			return fmt.Errorf("parsing pid from %q: %w", pidFile, err)
+		}
+	}
+
+	proc, err := os.FindProcess(pid)
+	if err != nil {
+		return fmt.Errorf("finding process with pid %d: %w", pid, err)
+	}
+
+	err = proc.Signal(syscall.SIGHUP)
+	if err != nil {
+		return fmt.Errorf("sending sighup to process with pid %d: %w", pid, err)
+	}
+
+	return nil
+}

internal/ossvc/manager_windows.go

@@ -0,0 +1,15 @@
+//go:build windows
+
+package ossvc
+
+import (
+	"context"
+
+	"github.com/AdguardTeam/golibs/errors"
+)
+
+// reload is a Windows platform implementation of the Reload method of the
+// [ReloadManager] interface for *manager.
+func (*manager) reload(context.Context, ServiceName) error {
+	return errors.ErrUnsupported
+}

scripts/make/go-lint.sh

@@ -210,6 +210,7 @@ run_linter "$go" tool gocognit --over='10' \
 	./internal/home/ \
 	./internal/ipset \
 	./internal/next/ \
+	./internal/ossvc/ \
 	./internal/rdns/ \
 	./internal/schedule/ \
 	./internal/stats/ \
@@ -257,6 +258,7 @@ run_linter "$go" tool fieldalignment \
 	./internal/filtering/safesearch/ \
 	./internal/ipset/ \
 	./internal/next/... \
+	./internal/ossvc/ \
 	./internal/querylog/ \
 	./internal/rdns/ \
 	./internal/schedule/ \
@@ -290,6 +292,7 @@ run_linter "$go" tool gosec --exclude=G115 --fmt=golint --quiet \
 	./internal/filtering/safesearch/ \
 	./internal/ipset/ \
 	./internal/next/ \
+	./internal/ossvc/ \
 	./internal/rdns/ \
 	./internal/schedule/ \
 	./internal/stats/ \