[v4,3/4] sysklogd: rewrite init script

- Split it into S01syslogd and S02klogd to make every init script be
  called the same as the executable it starts.
- Implement start, stop, restart and reload as functions, like in other
  init scripts, using start-stop-daemon.
- Indent with tabs, not spaces.
- Detect and report start/stop errors (previous version ignored them and
  always reported OK).
- Support /etc/default/$DAEMON configuration files.
- Do not kill syslogd in "reload". Send a SIGHUP signal, instructing it
  to perform a re-initialization.
- Do not kill klogd in "reload". Send a signal (default 0, which does
  nothing).  Users can configure this signal in /etc/default/klogd to
  either SIGUSR1 or SIGUSR2.

Signed-off-by: Carlos Santos <casantos@datacom.com.br>
---
Changes v1->v2
- Implement suggestions made by Arnout Vandecappelle
Changes v2->v3
- Include /etc/default/logging, not /etc/default/$DAEMON.
Changes v3-v4
- Follow the decisions taken at the Buildroot meeting.
- Leave the daemon args themselves on a separate line, as suggested by
  Arnout Vandecappelle.
- Use a less fancy commit message :-)
---
 package/sysklogd/S01logging  | 25 --------------
 package/sysklogd/S01syslogd  | 62 ++++++++++++++++++++++++++++++++++
 package/sysklogd/S02klogd    | 65 ++++++++++++++++++++++++++++++++++++
 package/sysklogd/sysklogd.mk |  6 ++--
 4 files changed, 131 insertions(+), 27 deletions(-)
 delete mode 100644 package/sysklogd/S01logging
 create mode 100644 package/sysklogd/S01syslogd
 create mode 100644 package/sysklogd/S02klogd

Carlos,

On Sat, Nov 3, 2018 at 1:24 PM Carlos Santos <casantos@datacom.com.br> wrote:
>
> - Split it into S01syslogd and S02klogd to make every init script be
>   called the same as the executable it starts.
> - Implement start, stop, restart and reload as functions, like in other
>   init scripts, using start-stop-daemon.
> - Indent with tabs, not spaces.
> - Detect and report start/stop errors (previous version ignored them and
>   always reported OK).
> - Support /etc/default/$DAEMON configuration files.
> - Do not kill syslogd in "reload". Send a SIGHUP signal, instructing it
>   to perform a re-initialization.
> - Do not kill klogd in "reload". Send a signal (default 0, which does
>   nothing).  Users can configure this signal in /etc/default/klogd to
>   either SIGUSR1 or SIGUSR2.
>
> Signed-off-by: Carlos Santos <casantos@datacom.com.br>
> ---
> Changes v1->v2
> - Implement suggestions made by Arnout Vandecappelle
> Changes v2->v3
> - Include /etc/default/logging, not /etc/default/$DAEMON.
> Changes v3-v4
> - Follow the decisions taken at the Buildroot meeting.
> - Leave the daemon args themselves on a separate line, as suggested by
>   Arnout Vandecappelle.
> - Use a less fancy commit message :-)
> ---
>  package/sysklogd/S01logging  | 25 --------------
>  package/sysklogd/S01syslogd  | 62 ++++++++++++++++++++++++++++++++++
>  package/sysklogd/S02klogd    | 65 ++++++++++++++++++++++++++++++++++++
>  package/sysklogd/sysklogd.mk |  6 ++--
>  4 files changed, 131 insertions(+), 27 deletions(-)
>  delete mode 100644 package/sysklogd/S01logging
>  create mode 100644 package/sysklogd/S01syslogd
>  create mode 100644 package/sysklogd/S02klogd
>
> diff --git a/package/sysklogd/S01logging b/package/sysklogd/S01logging
> deleted file mode 100644
> index 1cbfe869fa..0000000000
> --- a/package/sysklogd/S01logging
> +++ /dev/null
> @@ -1,25 +0,0 @@
> -#!/bin/sh
> -
> -case "$1" in
> -       start)
> -               printf "Starting logging: "
> -               /sbin/syslogd -m 0
> -               /sbin/klogd
> -               echo "OK"
> -               ;;
> -       stop)
> -               printf "Stopping logging: "
> -               [ -f /var/run/klogd.pid ] && kill `cat /var/run/klogd.pid`
> -               [ -f /var/run/syslogd.pid ] && kill `cat /var/run/syslogd.pid`
> -               echo "OK"
> -               ;;
> -       restart|reload)
> -               $0 stop
> -               $0 start
> -               ;;
> -       *)
> -               echo "Usage: $0 {start|stop|restart}"
> -               exit 1
> -esac
> -
> -exit $?
> diff --git a/package/sysklogd/S01syslogd b/package/sysklogd/S01syslogd
> new file mode 100644
> index 0000000000..d0951f0235
> --- /dev/null
> +++ b/package/sysklogd/S01syslogd
> @@ -0,0 +1,62 @@
> +#!/bin/sh
> +
> +DAEMON="syslogd"
> +PIDFILE="/var/run/$DAEMON.pid"
> +
> +SYSLOGD_ARGS="-m 0"
> +
> +# shellcheck source=/dev/null
> +[ -r "/etc/default/$DAEMON" ] && . "/etc/default/$DAEMON"
> +
> +start() {
> +       printf 'Starting %s: ' "$DAEMON"
> +       # shellcheck disable=SC2086 # we need the word splitting
> +       start-stop-daemon -S -q -p "$PIDFILE" -x "/sbin/$DAEMON" \
> +               -- $SYSLOGD_ARGS
> +       status=$?
> +       if [ "$status" -eq 0 ]; then
> +               echo "OK"
> +       else
> +               echo "FAIL"
> +       fi
> +       return "$status"
> +}
> +
> +stop() {
> +       printf 'Stopping %s: ' "$DAEMON"
> +       start-stop-daemon -K -q -p "$PIDFILE"
> +       status=$?
> +       if [ "$status" -eq 0 ]; then
> +               echo "OK"
> +       else
> +               echo "FAIL"
> +       fi
> +       return "$status"
> +}
> +
> +restart() {
> +       stop

Similar question to the busybox syslog vs klog.  What happens if you
restart the syslog daemon with klogd not stopped?  Do we need to
handle that case with stopping it or printing a warning?

> +       sleep 1
> +       start
> +}
> +
> +# SIGHUP makes syslogd reload its configuration
> +reload() {
> +       printf 'Reloading %s: ' "$DAEMON"
> +       start-stop-daemon -K -s HUP -q -p "$PIDFILE"
> +       status=$?
> +       if [ "$status" -eq 0 ]; then
> +               echo "OK"
> +       else
> +               echo "FAIL"
> +       fi
> +       return "$status"
> +}
> +
> +case "$1" in
> +        start|stop|restart|reload)
> +                "$1";;
> +        *)
> +                echo "Usage: $0 {start|stop|restart|reload}"
> +                exit 1
> +esac
> diff --git a/package/sysklogd/S02klogd b/package/sysklogd/S02klogd
> new file mode 100644
> index 0000000000..93f39e1f0e
> --- /dev/null
> +++ b/package/sysklogd/S02klogd
> @@ -0,0 +1,65 @@
> +#!/bin/sh
> +
> +DAEMON="klogd"
> +PIDFILE="/var/run/$DAEMON.pid"
> +
> +KLOGD_ARGS=""
> +
> +KLOGD_RELOAD="0"
> +
> +# shellcheck source=/dev/null
> +[ -r "/etc/default/$DAEMON" ] && . "/etc/default/$DAEMON"
> +
> +start() {
> +       printf 'Starting %s: ' "$DAEMON"
> +       # shellcheck disable=SC2086 # we need the word splitting
> +       start-stop-daemon -S -q -p "$PIDFILE" -x "/sbin/$DAEMON" \
> +               -- $KLOGD_ARGS
> +       status=$?
> +       if [ "$status" -eq 0 ]; then
> +               echo "OK"
> +       else
> +               echo "FAIL"
> +       fi
> +       return "$status"
> +}
> +
> +stop() {
> +       printf 'Stopping %s: ' "$DAEMON"
> +       start-stop-daemon -K -q -p "$PIDFILE"
> +       status=$?
> +       if [ "$status" -eq 0 ]; then
> +               echo "OK"
> +       else
> +               echo "FAIL"
> +       fi
> +       return "$status"
> +}
> +
> +restart() {
> +       stop
> +       sleep 1
> +       start
> +}
> +
> +# SIGUSR1 makes klogd reload kernel module symbols
> +# SIGUSR2 makes klogd reload static kernel symbols and kernel module symbols
> +reload() {
> +       printf 'Reloading %s: ' "$DAEMON"
> +       start-stop-daemon -K -s "$KLOGD_RELOAD" -q -p "$PIDFILE"
> +       status=$?
> +       if [ "$status" -eq 0 ]; then
> +               echo "OK"
> +       else
> +               echo "FAIL"
> +       fi
> +       return "$status"
> +}
> +
> +case "$1" in
> +        start|stop|restart|reload)
> +                "$1";;
> +        *)
> +                echo "Usage: $0 {start|stop|restart|reload}"
> +                exit 1
> +esac
> diff --git a/package/sysklogd/sysklogd.mk b/package/sysklogd/sysklogd.mk
> index c4f064c10b..976438c110 100644
> --- a/package/sysklogd/sysklogd.mk
> +++ b/package/sysklogd/sysklogd.mk
> @@ -23,8 +23,10 @@ define SYSKLOGD_INSTALL_TARGET_CMDS
>  endef
>
>  define SYSKLOGD_INSTALL_INIT_SYSV
> -       $(INSTALL) -m 755 -D package/sysklogd/S01logging \
> -               $(TARGET_DIR)/etc/init.d/S01logging
> +       $(INSTALL) -m 755 -D package/sysklogd/S01syslogd \
> +               $(TARGET_DIR)/etc/init.d/S01syslogd
> +       $(INSTALL) -m 755 -D package/sysklogd/S02klogd \
> +               $(TARGET_DIR)/etc/init.d/S02klogd

So by default the user may take a busybox based target and get the
logging daemons from busybox's default config.  Then they choose to go
enable one of the other logging options but don't understand they need
to make a custom busybox config.  For sysklogd, the install would just
copy over the init scripts busybox installed, however do we need to
handle this case with rsyslog(S02klogd would be left in the target
from busybox) and syslog-ng(both S01/S02 would be left) ?  Maybe a
check for existance and exit with warning that the busybox
configuration needs to have logging disabled....

Reviewed-by: Matt Weber <matthew.weber@rockwellcollins.com>

On 05/11/18 15:07, Matthew Weber wrote:
> So by default the user may take a busybox based target and get the
> logging daemons from busybox's default config.  Then they choose to go
> enable one of the other logging options but don't understand they need
> to make a custom busybox config.  For sysklogd, the install would just
> copy over the init scripts busybox installed, however do we need to
> handle this case with rsyslog(S02klogd would be left in the target
> from busybox) and syslog-ng(both S01/S02 would be left) ?  Maybe a
> check for existance and exit with warning that the busybox
> configuration needs to have logging disabled....

 That is handled in busybox.mk:

+# Only install our logging scripts if no other package does it.
+ifeq ($(BR2_PACKAGE_SYSKLOGD)$(BR2_PACKAGE_RSYSLOG)$(BR2_PACKAGE_SYSLOG_NG),)
 define BUSYBOX_INSTALL_LOGGING_SCRIPT


 Regards,
 Arnout

Arnout,

On Tue, Nov 6, 2018 at 6:08 PM Arnout Vandecappelle <arnout@mind.be> wrote:
>
>
>
> On 05/11/18 15:07, Matthew Weber wrote:
> > So by default the user may take a busybox based target and get the
> > logging daemons from busybox's default config.  Then they choose to go
> > enable one of the other logging options but don't understand they need
> > to make a custom busybox config.  For sysklogd, the install would just
> > copy over the init scripts busybox installed, however do we need to
> > handle this case with rsyslog(S02klogd would be left in the target
> > from busybox) and syslog-ng(both S01/S02 would be left) ?  Maybe a
> > check for existance and exit with warning that the busybox
> > configuration needs to have logging disabled....
>
>  That is handled in busybox.mk:
>
> +# Only install our logging scripts if no other package does it.
> +ifeq ($(BR2_PACKAGE_SYSKLOGD)$(BR2_PACKAGE_RSYSLOG)$(BR2_PACKAGE_SYSLOG_NG),)
>  define BUSYBOX_INSTALL_LOGGING_SCRIPT
>
>

Agree, just more of a "if you don't do a clean build" what questions
will hit the mailing list and how could we prevent that.....

Matt

Superseded-by: https://patchwork.ozlabs.org/patch/994014/