bug#16507: [RFC] Add a systemd service file for dealing with emacs --daemon.

bug#16507: [RFC] Add a systemd service file for dealing with emacs --daemon.

[Rüdiger Sonderfeld]

As discussed in Bug#16507, I've added a systemd service file to deal with 
emacs --daemon.  This however requires some installation changes.  That's why 
I submit this patch for review before pushing it.

A new configuration flag `--with-systemduserunitdir' is added to set the 
installation directory for the user unit.  If it is unset an attempt is made 
to locate the default directory by using pkg-config.

(I guess this should also get an entry in etc/NEWS.)

* configure.ac (with_systemduserunitdir): New option.
* Makefile.in (systemdunitdir,SYSTEMD_UNITS): New variables.
(install-etc): Install systemd unit file.
(uninstall): Uninstall systemd unit file.
* etc/emacs.service.in: New file.
---
 ChangeLog            |  8 ++++++++
 Makefile.in          | 17 +++++++++++++++++
 configure.ac         | 19 +++++++++++++++++++
 etc/ChangeLog        |  5 +++++
 etc/emacs.service.in | 14 ++++++++++++++
 5 files changed, 63 insertions(+)
 create mode 100644 etc/emacs.service.in

diff --git a/ChangeLog b/ChangeLog
index cd7698c..05ad878 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2014-12-03  Rüdiger Sonderfeld  <ruediger@c-plusplus.de>
+
+	Add a systemd service file for dealing with emacs --daemon.
+	* configure.ac (with_systemduserunitdir): New option.
+	* Makefile.in (systemdunitdir,SYSTEMD_UNITS): New variables.
+	(install-etc): Install systemd unit file.
+	(uninstall): Uninstall systemd unit file.
+
 2014-12-01  Lars Magne Ingebrigtsen  <larsi@gnus.org>
 
 	* .gitignore: Ignore loaddefs directly under lisp, and in
diff --git a/Makefile.in b/Makefile.in
index ccb70a4..b1e6be5 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -241,6 +241,9 @@ etcdocdir=@etcdocdir@
 # Where to install Emacs game score files.
 gamedir=@gamedir@
 
+# Where to install systemd unit files.
+systemdunitdir=@systemdunitdir@
+
 # ==================== Utility Programs for the Build ====================
 
 # Allow the user to specify the install program.
@@ -286,6 +289,9 @@ SUBDIR_MAKEFILES = `echo $(SUBDIR_MAKEFILES_IN:.in=) | sed 
's|$(srcdir)/||g'`
 COPYDIR = ${srcdir}/etc ${srcdir}/lisp
 COPYDESTS = "$(DESTDIR)${etcdir}" "$(DESTDIR)${lispdir}"
 
+# systemd unit
+SYSTEMD_UNITS = @SYSTEMD_UNITS@
+
 all: ${SUBDIR} info
 
 .PHONY: all ${SUBDIR} blessmail epaths-force epaths-force-w32 etc-emacsver
@@ -716,6 +722,16 @@ install-etc:
 	    || exit 1; \
 	  done ; \
 	done
+	if test "x$(SYSTEMD_UNITS)" = "xemacs.service" ; then \
+	  tmp=etc/emacs.service; rm -f $${tmp}; \
+	  sed \
+            -e "s;@emacs_prog@;${bindir}/${EMACSFULL};" \
+	    -e "s;@emacsclient_prog@;${bindir}/emacsclient${EXEEXT};" \
+	    "$(srcdir)/etc/emacs.service.in" > $${tmp}; \
+	  umask 022; $(MKDIR_P) "$(DESTDIR)$(systemdunitdir)"; \
+	  $(INSTALL_DATA) $${tmp} "$(DESTDIR)$(systemdunitdir)/emacs.service"; \
+	  rm -f $${tmp}; \
+	fi
 
 ### Build Emacs and install it, stripping binaries while installing them.
 install-strip:
@@ -771,6 +787,7 @@ uninstall: uninstall-$(NTDIR) uninstall-doc
 	  file="$(DESTDIR)${gamedir}/$${file}"; \
 	  [ -s "$${file}" ] || rm -f "$$file"; \
 	done
+	-rm -f "$(DESTDIR)$(systemdunitdir)/emacs.service"
 
 ### Windows-specific uninstall target for removing programs produced
 ### in nt/, and its Posix do-nothing shadow.
diff --git a/configure.ac b/configure.ac
index 010abc8..e737f1b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -374,6 +374,10 @@ otherwise for the first of `gfile' or `inotify' that is 
usable.])
  ],
  [with_file_notification=$with_features])
 
+AC_ARG_WITH([systemduserunitdir],
+ AS_HELP_STRING([--with-systemduserunitdir=DIR], [Directory for systemd user 
service files]),
+ [], [with_systemduserunitdir=default])
+
 ## For the times when you want to build Emacs but don't have
 ## a suitable makeinfo, and can live without the manuals.
 dnl http://lists.gnu.org/archive/html/emacs-devel/2008-04/msg01844.html
@@ -2678,6 +2682,21 @@ AC_SUBST(NOTIFY_OBJ)
 AC_SUBST(GFILENOTIFY_CFLAGS)
 AC_SUBST(GFILENOTIFY_LIBS)
 
+if test "x$with_systemduserunitdir" != xno; then
+  if test "x$with_systemduserunitdir" = xdefault; then
+    with_systemduserunitdir=`"$PKG_CONFIG" --variable=systemduserunitdir 
systemd`
+  fi
+  AC_SUBST([systemdunitdir], [$with_systemduserunitdir])
+fi
+
+if test -n "$with_systemduserunitdir" -a "x$with_systemduserunitdir" != xno ; 
then
+  SYSTEMD_UNITS="emacs.service"
+else
+  SYSTEMD_UNITS=""
+fi
+
+AC_SUBST(SYSTEMD_UNITS)
+
 dnl Do not put whitespace before the #include statements below.
 dnl Older compilers (eg sunos4 cc) choke on it.
 HAVE_XAW3D=no
diff --git a/etc/ChangeLog b/etc/ChangeLog
index 4f672df..02c0895 100644
--- a/etc/ChangeLog
+++ b/etc/ChangeLog
@@ -1,3 +1,8 @@
+2014-12-03  Rüdiger Sonderfeld  <ruediger@c-plusplus.de>
+
+	Add a systemd service file for dealing with emacs --daemon.
+	* emacs.service.in: New file.
+
 2014-12-02  Eli Zaretskii  <eliz@gnu.org>
 
 	* NEWS: Mention 'bidi-find-overridden-directionality'.
diff --git a/etc/emacs.service.in b/etc/emacs.service.in
new file mode 100644
index 0000000..0e59bc2
--- /dev/null
+++ b/etc/emacs.service.in
@@ -0,0 +1,14 @@
+# -*- conf-mode -*-
+# Copyright (C) 2014 Free Software Foundation, Inc.
+[Unit]
+Description=Emacs: the extensible, customizable text editor - and more.
+Documentation=info:Emacs man:emacs(1) https://gnu.org/software/emacs/
+
+[Service]
+Type=forking
+ExecStart=@emacs_prog@ --daemon
+ExecStop=@emacsclient_prog@ --eval "(kill-emacs)"
+Restart=on-failure
+
+[Install]
+WantedBy=default.target
-- 
2.1.3

Re: [RFC] Add a systemd service file for dealing with emacs --daemon.

[Romain Francoise]

Hi,

On Wed, Dec 03, 2014 at 08:39:44PM +0100, Rüdiger Sonderfeld wrote:
> As discussed in Bug#16507, I've added a systemd service file to deal
> with emacs --daemon. This however requires some installation changes.
> That's why I submit this patch for review before pushing it.

Is this something that distributions would be expected to enable?
Because I use both systemd and Emacs, yet I absolutely don't want to
have an Emacs daemon started by default in my user instance.

Also, by default user instances are killed when the last session is
closed, which would therefore kill the emacs process and kinda defeat
the point of having a persistent daemon.

Re: [RFC] Add a systemd service file for dealing with emacs --daemon.

[joakim]

Rüdiger Sonderfeld <ruediger@c-plusplus.net> writes:

> As discussed in Bug#16507, I've added a systemd service file to deal with 
> emacs --daemon.  This however requires some installation changes.  That's why 
> I submit this patch for review before pushing it.
>
> A new configuration flag `--with-systemduserunitdir' is added to set the 
> installation directory for the user unit.  If it is unset an attempt is made 
> to locate the default directory by using pkg-config.
>
> (I guess this should also get an entry in etc/NEWS.)
>
> * configure.ac (with_systemduserunitdir): New option.
> * Makefile.in (systemdunitdir,SYSTEMD_UNITS): New variables.
> (install-etc): Install systemd unit file.
> (uninstall): Uninstall systemd unit file.
> * etc/emacs.service.in: New file.
> ---
>  ChangeLog            |  8 ++++++++
>  Makefile.in          | 17 +++++++++++++++++
>  configure.ac         | 19 +++++++++++++++++++
>  etc/ChangeLog        |  5 +++++
>  etc/emacs.service.in | 14 ++++++++++++++
>  5 files changed, 63 insertions(+)
>  create mode 100644 etc/emacs.service.in
>
> diff --git a/ChangeLog b/ChangeLog
> index cd7698c..05ad878 100644
> --- a/ChangeLog
> +++ b/ChangeLog
> @@ -1,3 +1,11 @@
> +2014-12-03  Rüdiger Sonderfeld  <ruediger@c-plusplus.de>
> +
> +	Add a systemd service file for dealing with emacs --daemon.
> +	* configure.ac (with_systemduserunitdir): New option.
> +	* Makefile.in (systemdunitdir,SYSTEMD_UNITS): New variables.
> +	(install-etc): Install systemd unit file.
> +	(uninstall): Uninstall systemd unit file.
> +
>  2014-12-01  Lars Magne Ingebrigtsen  <larsi@gnus.org>
>  
>  	* .gitignore: Ignore loaddefs directly under lisp, and in
> diff --git a/Makefile.in b/Makefile.in
> index ccb70a4..b1e6be5 100644
> --- a/Makefile.in
> +++ b/Makefile.in
> @@ -241,6 +241,9 @@ etcdocdir=@etcdocdir@
>  # Where to install Emacs game score files.
>  gamedir=@gamedir@
>  
> +# Where to install systemd unit files.
> +systemdunitdir=@systemdunitdir@
> +
>  # ==================== Utility Programs for the Build ====================
>  
>  # Allow the user to specify the install program.
> @@ -286,6 +289,9 @@ SUBDIR_MAKEFILES = `echo $(SUBDIR_MAKEFILES_IN:.in=) | sed 
> 's|$(srcdir)/||g'`
>  COPYDIR = ${srcdir}/etc ${srcdir}/lisp
>  COPYDESTS = "$(DESTDIR)${etcdir}" "$(DESTDIR)${lispdir}"
>  
> +# systemd unit
> +SYSTEMD_UNITS = @SYSTEMD_UNITS@
> +
>  all: ${SUBDIR} info
>  
>  .PHONY: all ${SUBDIR} blessmail epaths-force epaths-force-w32 etc-emacsver
> @@ -716,6 +722,16 @@ install-etc:
>  	    || exit 1; \
>  	  done ; \
>  	done
> +	if test "x$(SYSTEMD_UNITS)" = "xemacs.service" ; then \
> +	  tmp=etc/emacs.service; rm -f $${tmp}; \
> +	  sed \
> +            -e "s;@emacs_prog@;${bindir}/${EMACSFULL};" \
> +	    -e "s;@emacsclient_prog@;${bindir}/emacsclient${EXEEXT};" \
> +	    "$(srcdir)/etc/emacs.service.in" > $${tmp}; \
> +	  umask 022; $(MKDIR_P) "$(DESTDIR)$(systemdunitdir)"; \
> +	  $(INSTALL_DATA) $${tmp} "$(DESTDIR)$(systemdunitdir)/emacs.service"; \
> +	  rm -f $${tmp}; \
> +	fi
>  
>  ### Build Emacs and install it, stripping binaries while installing them.
>  install-strip:
> @@ -771,6 +787,7 @@ uninstall: uninstall-$(NTDIR) uninstall-doc
>  	  file="$(DESTDIR)${gamedir}/$${file}"; \
>  	  [ -s "$${file}" ] || rm -f "$$file"; \
>  	done
> +	-rm -f "$(DESTDIR)$(systemdunitdir)/emacs.service"
>  
>  ### Windows-specific uninstall target for removing programs produced
>  ### in nt/, and its Posix do-nothing shadow.
> diff --git a/configure.ac b/configure.ac
> index 010abc8..e737f1b 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -374,6 +374,10 @@ otherwise for the first of `gfile' or `inotify' that is 
> usable.])
>   ],
>   [with_file_notification=$with_features])
>  
> +AC_ARG_WITH([systemduserunitdir],
> + AS_HELP_STRING([--with-systemduserunitdir=DIR], [Directory for systemd user 
> service files]),
> + [], [with_systemduserunitdir=default])
> +
>  ## For the times when you want to build Emacs but don't have
>  ## a suitable makeinfo, and can live without the manuals.
>  dnl http://lists.gnu.org/archive/html/emacs-devel/2008-04/msg01844.html@@ -2678,6 +2682,21 @@ AC_SUBST(NOTIFY_OBJ)
>  AC_SUBST(GFILENOTIFY_CFLAGS)
>  AC_SUBST(GFILENOTIFY_LIBS)
>  
> +if test "x$with_systemduserunitdir" != xno; then
> +  if test "x$with_systemduserunitdir" = xdefault; then
> +    with_systemduserunitdir=`"$PKG_CONFIG" --variable=systemduserunitdir 
> systemd`
> +  fi
> +  AC_SUBST([systemdunitdir], [$with_systemduserunitdir])
> +fi
> +
> +if test -n "$with_systemduserunitdir" -a "x$with_systemduserunitdir" != xno ; 
> then
> +  SYSTEMD_UNITS="emacs.service"
> +else
> +  SYSTEMD_UNITS=""
> +fi
> +
> +AC_SUBST(SYSTEMD_UNITS)
> +
>  dnl Do not put whitespace before the #include statements below.
>  dnl Older compilers (eg sunos4 cc) choke on it.
>  HAVE_XAW3D=no
> diff --git a/etc/ChangeLog b/etc/ChangeLog
> index 4f672df..02c0895 100644
> --- a/etc/ChangeLog
> +++ b/etc/ChangeLog
> @@ -1,3 +1,8 @@
> +2014-12-03  Rüdiger Sonderfeld  <ruediger@c-plusplus.de>
> +
> +	Add a systemd service file for dealing with emacs --daemon.
> +	* emacs.service.in: New file.
> +
>  2014-12-02  Eli Zaretskii  <eliz@gnu.org>
>  
>  	* NEWS: Mention 'bidi-find-overridden-directionality'.
> diff --git a/etc/emacs.service.in b/etc/emacs.service.in
> new file mode 100644
> index 0000000..0e59bc2
> --- /dev/null
> +++ b/etc/emacs.service.in
> @@ -0,0 +1,14 @@
> +# -*- conf-mode -*-
> +# Copyright (C) 2014 Free Software Foundation, Inc.
> +[Unit]
> +Description=Emacs: the extensible, customizable text editor - and more.
> +Documentation=info:Emacs man:emacs(1) https://gnu.org/software/emacs/+
> +[Service]
> +Type=forking
> +ExecStart=@emacs_prog@ --daemon
> +ExecStop=@emacsclient_prog@ --eval "(kill-emacs)"
> +Restart=on-failure
> +
> +[Install]
> +WantedBy=default.target

I have a unit file that enables ssh-agent, which is otherwise a problem.
I'm not sure if its generally usable.


[Unit]
Description=Emacs: the extensible, self-documenting text editor

[Service]
Type=forking
ExecStart=/usr/bin/ssh-agent /usr/local/bin/emacs --daemon
ExecStop=/usr/local/bin/emacs --eval "(progn (setq kill-emacs-hook 'nil) (kill-emacs))"
Restart=always
User=%i
WorkingDirectory=%h

[Install]
WantedBy=multi-user.target


The corresponding elisp looks like (warning, lame hard-coding):

(defun ssh-agent-init ()
  (interactive)
  (save-excursion
    (if (get-buffer "ssh-agent-process") (kill-buffer "ssh-agent-process" ))

    (with-current-buffer     (get-buffer-create "ssh-agent-process")
      (call-process "ssh-agent" nil t t  "-c" "-a" "/home/joakim/.ssh-agent-sock")

      (goto-char (point-min))

      (message "buf: %s cont: %s"(current-buffer) (buffer-string))

      (search-forward-regexp ".* .* \\(.*\\);")
      (message "1: %s" (match-string 0)(match-string 1))
      (setenv "SSH_AUTH_SOCK" (match-string 1))
      (setq ssh-auth-sock (getenv "SSH_AUTH_SOCK" ))
      (message "%s" (getenv "SSH_AUTH_SOCK" )))
    )
  )


(setenv "SSH_AUTH_SOCK" "/home/joakim/.ssh-agent-sock")

;;from the internetz
;; - it hangs, but works anyway
;; - it should also run ssh-agent-init intelligently

(defun ssh-add-process-filter (process string)
  (save-match-data
    (if (string-match ":\\s *\\'" string)
        (process-send-string process (concat (read-passwd string) "\n"))
      (message "%s" string))))
(defun ssh-add ()
  "Run ssh-add to add a key to the running SSH agent.
Let Emacs prompt for the passphrase."
(interactive)
  (let ((process-connection-type t)
            process)
    (unwind-protect
        (progn
          (setq process (start-process "ssh-add" nil
                                       "ssh-add" ))
          (set-process-filter process 'ssh-add-process-filter)
          (while (accept-process-output process)))
      (if (eq (process-status process) 'run)
          (kill-process process)))))


-- 
Joakim Verona

Re: [RFC] Add a systemd service file for dealing with emacs --daemon.

[Rüdiger Sonderfeld]

On Wednesday 03 December 2014 22:08:37 Romain Francoise wrote:
> Is this something that distributions would be expected to enable?
> Because I use both systemd and Emacs, yet I absolutely don't want to
> have an Emacs daemon started by default in my user instance.

It's something the user would be expected to enable.  This should only provide 
the service file and the user can then enable it, using

    systemctl enable --user emacs.service

(or disable it by using disable).

> Also, by default user instances are killed when the last session is
> closed, which would therefore kill the emacs process and kinda defeat
> the point of having a persistent daemon.

Users should be able to prevent this, by using `loginctl enable-linger'.

Regards,
Rüdiger

Re: [RFC] Add a systemd service file for dealing with emacs --daemon.

[Ulrich Mueller]

>>>>> On Wed, 03 Dec 2014, Romain Francoise wrote:

> Is this something that distributions would be expected to enable?

As it is proposed, it won't work for Gentoo. We support installation
of several Emacs versions in parallel, so a systemd unit file
installed under a fixed path name would lead to file collisions
between different versions.

Which means that we shall disable installation of the file in Gentoo.
(Besides, systemd isn't our default init system ...)

Re: [RFC] Add a systemd service file for dealing with emacs --daemon.

[Rüdiger Sonderfeld]

On Wednesday 03 December 2014 23:08:29 Ulrich Mueller wrote:
> >>>>> On Wed, 03 Dec 2014, Romain Francoise wrote:
> > Is this something that distributions would be expected to enable?
> 
> As it is proposed, it won't work for Gentoo. We support installation
> of several Emacs versions in parallel, so a systemd unit file
> installed under a fixed path name would lead to file collisions
> between different versions.
> 
> Which means that we shall disable installation of the file in Gentoo.
> (Besides, systemd isn't our default init system ...)

Multiple versions are indeed an issue.  I don't know if the systemd folks have 
a suggestion for that case.  But as far as I understand the recommendation is 
indeed to install unit files to the directory given by pkg-config.

The installation directory can of course be changed and you could simply point 
it elsewhere and then have the user copy the unit file she wants.

Regards,
Rüdiger

RE: bug#16507: [RFC] Add a systemd service file for dealing with emacs --daemon.

[Drew Adams]

Please drop one or the other from the recipients list:
emacs-devel or debbugs.

Re: bug#16507: [RFC] Add a systemd service file for dealing with emacs --daemon.

[Glenn Morris]

Thanks, looks nice.
(Don't see why it needed to be posted to two mailing lists though.)

Should the name of the service file not respect program-transform though?
Ie, if I am installing the Emacs binary as "emacs24", should the service
file not be installed as "emacs24.service"?

Re: [RFC] Add a systemd service file for dealing with emacs --daemon.

[Ulrich Mueller]

>>>>> On Thu, 04 Dec 2014, Rüdiger Sonderfeld wrote:

> On Wednesday 03 December 2014 23:08:29 Ulrich Mueller wrote:
>> Which means that we shall disable installation of the file in
>> Gentoo. (Besides, systemd isn't our default init system ...)

> Multiple versions are indeed an issue. I don't know if the systemd
> folks have a suggestion for that case. But as far as I understand
> the recommendation is indeed to install unit files to the directory
> given by pkg-config.

> The installation directory can of course be changed and you could
> simply point it elsewhere and then have the user copy the unit file
> she wants.

IIUC, a copy of the file is installed with the data-directory (etc/)
anyway? So the file will be available to the user, even if not
installed in the pkgconfig location.

Alternatively, if there is users' demand for it, we (Gentoo) could
add the unit to another package (like app-emacs/emacs-common-gentoo
which contains the desktop files, or app-emacs/emacs-daemon). We try
to keep the number of files installed such at a minimum, though, and
follow upstream's install locations whereever possible.

Re: [RFC] Add a systemd service file for dealing with emacs --daemon.

[Rüdiger Sonderfeld]

On Thursday 04 December 2014 07:26:53 Ulrich Mueller wrote:
> IIUC, a copy of the file is installed with the data-directory (etc/)
> anyway? So the file will be available to the user, even if not
> installed in the pkgconfig location.

No, the data directory etc/ should not be automatically be installed anywhere.  
The emacs.service file is only generated and installed, if either pkgconfig 
provides the default location or the user explicitly sets it.

> Alternatively, if there is users' demand for it, we (Gentoo) could
> add the unit to another package (like app-emacs/emacs-common-gentoo
> which contains the desktop files, or app-emacs/emacs-daemon). We try
> to keep the number of files installed such at a minimum, though, and
> follow upstream's install locations whereever possible.

That probably makes sense.