Eventscript function: change service_start into a function.

service_start is currently a variable.  This makes passing arguments
hard.  We change it to be a function and put default definitions into
the functions file.

We use a convention that if a service name argument is passed to a
redefined version of service_start() or service_stop() then it will
act unconditionally.  If no argument is passed then it can use
internal logic to decide if services should really be started.  This
is useful when a single eventscript handles multiple services.

This is a cherry-pick of ae38895 that needed to be reset mid-stream.
There is still some breakage following this commit.

Signed-off-by: Martin Schwenke <martin@meltin.net>

(This used to be ctdb commit 86e4aefed9fd1028660c98e3ea758c2b75ffc1d8)

6 files changed, 93 insertions, 50 deletions

diff --git a/ctdb/config/events.d/31.clamd b/ctdb/config/events.d/31.clamd
index 73454d7c53..53739e24f3 100644..100755
--- a/ctdb/config/events.d/31.clamd
+++ b/ctdb/config/events.d/31.clamd
@@ -16,8 +16,11 @@ case $CTDB_INIT_STYLE in
 		;;
 esac
 
-service_start="service $service_name stop > /dev/null 2>&1 ; service $service_name start"
-service_stop="service $service_name stop"
+service_start ()
+{
+    service $service_name stop > /dev/null 2>&1
+    service $service_name start
+}
 
 loadconfig
 
diff --git a/ctdb/config/events.d/40.vsftpd b/ctdb/config/events.d/40.vsftpd
index 72190db2a6..8ce2066348 100755
--- a/ctdb/config/events.d/40.vsftpd
+++ b/ctdb/config/events.d/40.vsftpd
@@ -5,8 +5,15 @@
 
 service_name="vsftpd"
 # make sure the service is stopped first
-service_start="service $service_name stop > /dev/null 2>&1 ; service $service_name start"
-service_stop="service $service_name stop > /dev/null 2>&1"
+service_start ()
+{
+    service $service_name stop > /dev/null 2>&1
+    service $service_name start
+}
+service_stop ()
+{
+    service $service_name stop > /dev/null 2>&1
+}
 service_reconfigure="service $service_name restart"
 service_fail_limit=2
 service_tcp_ports=21
diff --git a/ctdb/config/events.d/41.httpd b/ctdb/config/events.d/41.httpd
index e94bde3fad..1115ba4c2c 100755
--- a/ctdb/config/events.d/41.httpd
+++ b/ctdb/config/events.d/41.httpd
@@ -27,8 +27,16 @@ cleanup_httpd_semaphore_leak() {
 
 ##########
 
-service_start="cleanup_httpd_semaphore_leak; service $service_name start"
-service_stop="service $service_name stop; killall -q -9 $service_name || true"
+service_start ()
+{
+    cleanup_httpd_semaphore_leak
+    service $service_name start
+}
+service_stop ()
+{
+    service $service_name stop
+    killall -q -9 $service_name || true
+}
 service_reconfigure="service $service_name restart"
 
 loadconfig
diff --git a/ctdb/config/events.d/50.samba b/ctdb/config/events.d/50.samba
index 8008c9c30d..461ea07098 100755
--- a/ctdb/config/events.d/50.samba
+++ b/ctdb/config/events.d/50.samba
@@ -25,17 +25,17 @@ case $CTDB_INIT_STYLE in
 esac
 
 service_name="samba"
-service_start="start_samba"
-service_stop="stop_samba"
 
 loadconfig
 
-start_samba() {
-	# create the state directory for samba
-	mkdir -p $CTDB_VARDIR/state/samba
+service_start ()
+{
+	# If set then we force-start the relevant service.
+	_service_name="$1"
 
 	# make sure samba is not already started
-	is_ctdb_managed_service "samba" && {
+	if [ "$_service_name" = "samba" ] || \
+	    is_ctdb_managed_service "samba" ; then
 		service "$CTDB_SERVICE_SMB" stop > /dev/null 2>&1
 		service "$CTDB_SERVICE_NMB" stop > /dev/null 2>&1
 		killall -0 -q smbd && {
@@ -49,10 +49,11 @@ start_samba() {
 		    # make absolutely sure samba is dead
 		    killall -q -9 nmbd
 		}
-	}
+	fi
 
 	# make sure winbind is not already started
-	check_ctdb_manages_winbind && {
+	if [ "$_service_name" = "winbind" ] || \
+	    check_ctdb_manages_winbind ; then
 		service "$CTDB_SERVICE_WINBIND" stop > /dev/null 2>&1
 		killall -0 -q winbindd && {
 		    sleep 1
@@ -60,47 +61,52 @@ start_samba() {
 		    killall -q -9 winbindd
 		}
 
-	}
+	fi
 
 	# start the winbind service
-	check_ctdb_manages_winbind && {
+	if [ "$_service_name" = "winbind" ] || \
+	    check_ctdb_manages_winbind ; then
 		service "$CTDB_SERVICE_WINBIND" start || {
-			echo failed to start winbind
-			exit 1
+		    echo failed to start winbind
+		    exit 1
 		}
-
-	}
+	fi
 
 	# start Samba service. Start it reniced, as under very heavy load 
 	# the number of smbd processes will mean that it leaves few cycles for
 	# anything else
-	is_ctdb_managed_service "samba" && {
+	if [ "$_service_name" = "samba" ] || \
+	    is_ctdb_managed_service "samba" ; then
 		net serverid wipe
 
 		nice_service "$CTDB_SERVICE_NMB" start || {
 			echo failed to start nmbd
 			exit 1
 		}
-
 		nice_service "$CTDB_SERVICE_SMB" start || {
 			echo failed to start samba
 			exit 1
 		}
-	}
-	return 0
+	fi
 }
 
-stop_samba() {
+service_stop ()
+{
+	# If set then we force-stop the relevant service.
+	_service_name="$1"
+
 	# shutdown Samba when ctdb goes down
-	is_ctdb_managed_service "samba" && {
+	if [ "$_service_name" = "samba" ] || \
+	    is_ctdb_managed_service "samba" ; then
 		service "$CTDB_SERVICE_SMB" stop
 		service "$CTDB_SERVICE_NMB" stop
-	}
+	fi
 
 	# stop the winbind service
-	check_ctdb_manages_winbind && {
+	if [ "$_service_name" = "winbind" ] || \
+	    check_ctdb_manages_winbind ; then
 		service "$CTDB_SERVICE_WINBIND" stop
-	}
+	fi
 
 	return 0
 }
diff --git a/ctdb/config/events.d/60.nfs b/ctdb/config/events.d/60.nfs
index c0207eeaed..bdd9427f02 100755
--- a/ctdb/config/events.d/60.nfs
+++ b/ctdb/config/events.d/60.nfs
@@ -1,19 +1,21 @@
 #!/bin/sh
 # script to manage nfs in a clustered environment
 
-start_nfs() {
-	mkdir -p $CTDB_VARDIR/state/nfs
-	mkdir -p $CTDB_VARDIR/state/statd/ip
-	startstop_nfs stop
-	startstop_nfs start
-	set_proc "sys/net/ipv4/tcp_tw_recycle" 1
-}
-
 . $CTDB_BASE/functions
 
 service_name="nfs"
-service_start="start_nfs"
-service_stop="startstop_nfs stop"
+service_start ()
+{
+    mkdir -p $CTDB_VARDIR/state/nfs
+    mkdir -p $CTDB_VARDIR/state/statd/ip
+    startstop_nfs stop
+    startstop_nfs start
+    set_proc "sys/net/ipv4/tcp_tw_recycle" 1
+}
+service_stop ()
+{
+    startstop_nfs stop
+}
 service_reconfigure="startstop_nfs restart"
 
 loadconfig
diff --git a/ctdb/config/functions b/ctdb/config/functions
index ee671e598e..452b8d0d97 100755
--- a/ctdb/config/functions
+++ b/ctdb/config/functions
@@ -731,23 +731,40 @@ ctdb_start_stop_service ()
 
 ctdb_service_start ()
 {
-    if [ -n "$service_start" ] ; then
-	eval $service_start || return $?
-    else
-	service "$service_name" start || return $?
-    fi
-    ctdb_counter_init
+    # Here we only want $1.  If no argument is passed then
+    # service_start needs to know.
+    service_start "$@" || return $?
+
+    ctdb_counter_init "$@"
 }
 
 ctdb_service_stop ()
 {
-    if [ -n "$service_stop" ] ; then
-	eval $service_stop
-    else
-	service "$service_name" stop
-    fi
+    service_stop "$@"
+}
+
+# Default service_start() and service_stop() functions.
+ 
+# These may be overridden in an eventscript.  When overriding, the
+# following convention must be followed.  If these functions are
+# called with no arguments then they may use internal logic to
+# determine whether the service is managed and, therefore, whether
+# they should take any action.  However, if the service name is
+# specified as an argument then an attempt must be made to start or
+# stop the service.  This is because the auto-start/stop code calls
+# them with the service name as an argument.
+service_start ()
+{
+    service "${1:-${service_name}}" start
+}
+
+service_stop ()
+{
+    service "${1:-${service_name}}" stop
 }
 
+##################################################################
+
 ctdb_standard_event_handler ()
 {
     case "$1" in