notify: Send all sd_notify signals from main caddy process (#4060)

Initial sd_notify support was added in #3963, but that sent signals from
both cmdRun and cmdReload.  This approach has two drawbacks:

- Reloads initiated via the API do not send signals.
- The signals are sent from different processes, which requires the
  `NotifyAccess=exec` directive in the unit file.

This change moves the NotifyReloading and NotifyReadiness invocations to
Load, which address both of those drawbacks.  It also adds a
complimentary NotifyStopping method which is invoked from handleStop.
All the notify methods are defined in a notify package to avoid an
import loop.

4 files changed, 0 insertions, 131 deletions

diff --git a/cmd/commandfuncs.go b/cmd/commandfuncs.go
index 77d95b9..d32b9c7 100644
--- a/cmd/commandfuncs.go
+++ b/cmd/commandfuncs.go
@@ -269,10 +269,6 @@ func cmdRun(fl Flags) (int, error) {
 		}
 	}
 
-	if err := NotifyReadiness(); err != nil {
-		caddy.Log().Error("unable to notify readiness to service manager", zap.Error(err))
-	}
-
 	select {}
 }
 
@@ -294,15 +290,6 @@ func cmdReload(fl Flags) (int, error) {
 	reloadCmdAddrFlag := fl.String("address")
 	reloadCmdForceFlag := fl.Bool("force")
 
-	if err := NotifyReloading(); err != nil {
-		caddy.Log().Error("unable to notify reloading to service manager", zap.Error(err))
-	}
-	defer func() {
-		if err := NotifyReadiness(); err != nil {
-			caddy.Log().Error("unable to notify readiness to service manager", zap.Error(err))
-		}
-	}()
-
 	// get the config in caddy's native format
 	config, configFile, err := loadConfig(reloadCmdConfigFlag, reloadCmdConfigAdapterFlag)
 	if err != nil {
diff --git a/cmd/notify.go b/cmd/notify.go
deleted file mode 100644
index 21e0e69..0000000
--- a/cmd/notify.go
+++ /dev/null
@@ -1,25 +0,0 @@
-// Copyright 2015 Matthew Holt and The Caddy Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package caddycmd
-
-// NotifyReadiness notifies process manager of readiness.
-func NotifyReadiness() error {
-	return notifyReadiness()
-}
-
-// NotifyReloading notifies process manager of reloading.
-func NotifyReloading() error {
-	return notifyReloading()
-}
diff --git a/cmd/notify_linux.go b/cmd/notify_linux.go
deleted file mode 100644
index 924c00f..0000000
--- a/cmd/notify_linux.go
+++ /dev/null
@@ -1,68 +0,0 @@
-// Copyright 2015 Matthew Holt and The Caddy Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package caddycmd
-
-import (
-	"io"
-	"net"
-	"os"
-	"strings"
-)
-
-// The documentation about this IPC protocol is available here:
-// https://www.freedesktop.org/software/systemd/man/sd_notify.html
-
-func sdNotify(path, payload string) error {
-	socketAddr := &net.UnixAddr{
-		Name: path,
-		Net:  "unixgram",
-	}
-
-	conn, err := net.DialUnix(socketAddr.Net, nil, socketAddr)
-	if err != nil {
-		return err
-	}
-	defer conn.Close()
-
-	if _, err := io.Copy(conn, strings.NewReader(payload)); err != nil {
-		return err
-	}
-	return nil
-}
-
-// notifyReadiness notifies systemd caddy that has finished its
-// initialization routines.
-func notifyReadiness() error {
-	val, ok := os.LookupEnv("NOTIFY_SOCKET")
-	if !ok || val == "" {
-		return nil
-	}
-	if err := sdNotify(val, "READY=1"); err != nil {
-		return err
-	}
-	return nil
-}
-
-// notifyReadiness notifies systemd that caddy is reloading its config.
-func notifyReloading() error {
-	val, ok := os.LookupEnv("NOTIFY_SOCKET")
-	if !ok || val == "" {
-		return nil
-	}
-	if err := sdNotify(val, "RELOADING=1"); err != nil {
-		return err
-	}
-	return nil
-}
diff --git a/cmd/notify_other.go b/cmd/notify_other.go
deleted file mode 100644
index 4425ed7..0000000
--- a/cmd/notify_other.go
+++ /dev/null
@@ -1,25 +0,0 @@
-// Copyright 2015 Matthew Holt and The Caddy Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-// +build !linux
-
-package caddycmd
-
-func notifyReadiness() error {
-	return nil
-}
-
-func notifyReloading() error {
-	return nil
-}