[oe] [meta-webserver][PATCH] apache2: wait for server to start/stop/restart

[adam.chappell at ni.com]

From: Adam Chappell <adam.chappell at ni.com>

Change start, stop, and restart functions in apache2 init script to return only
after completion (i.e. the server has started/stopped, not just received a kill
signal). Starting and stopping the server in quick sucession results in an error
because the server will attempt to stop before it has had time to start and vice
versa.

Signed-off-by: Adam Chappell <adam.chappell at ni.com>
---
 meta-webserver/recipes-httpd/apache2/files/init | 165 +++++++++++++++++++++++-
 1 file changed, 161 insertions(+), 4 deletions(-)

diff --git a/meta-webserver/recipes-httpd/apache2/files/init b/meta-webserver/recipes-httpd/apache2/files/init
index a1adbd7..758d133 100755
--- a/meta-webserver/recipes-httpd/apache2/files/init
+++ b/meta-webserver/recipes-httpd/apache2/files/init
@@ -28,14 +28,161 @@ test -f $APACHECTL || exit 0
 # ensure we don't leak environment vars into apachectl
 APACHECTL="env -i LANG=${LANG} PATH=${PATH} $APACHECTL"
 
+apache_conftest() {
+    if $($APACHECTL configtest > /dev/null 2>&1 ); then
+        return 0
+    else
+        return 1
+    fi
+}
+
+apache_wait_start() {
+    local STATUS=$1
+
+    if [ $STATUS != 0 ] ; then
+        return $STATUS
+    fi
+
+    local i=0
+    while : ; do
+            PIDTMP=$(pidof $DAEMON | tr ' ' '\n' | grep -w $(cat $PIDFILE))
+            if [ -n "${PIDTMP:-}" ] && kill -0 "${PIDTMP:-}" 2> /dev/null; then
+                    return $STATUS
+            fi
+
+            if [ $i = "20" ] ; then
+                    return 2
+            fi
+
+            sleep 1
+            i=$(($i+1))
+    done
+}
+
+apache_wait_stop() {
+    local STATUS=$1
+
+    if [ $STATUS != 0 ] ; then
+        return $STATUS
+    fi
+
+    PIDTMP=$(pidof $DAEMON | tr ' ' '\n' | grep -w $(cat $PIDFILE))
+    if [ -n "${PIDTMP:-}" ] && kill -0 "${PIDTMP:-}" 2> /dev/null; then
+            local i=0
+            while kill -0 "${PIDTMP:-}" 2> /dev/null;  do
+                    if [ $i = '60' ]; then
+                            STATUS=2
+                            break
+                    fi
+                    sleep 1
+                    i=$(($i+1))
+            done
+            return $STATUS
+    else
+        return $STATUS
+    fi
+}
+
+#
+# Function that starts the daemon/service
+#
+do_start()
+{
+    # Return
+    #   0 if daemon has been started
+    #   1 if daemon was already running
+    #   2 if daemon could not be started
+
+    if [ -e $PIDFILE ] && pidof $DAEMON | tr ' ' '\n' | grep -w $(cat $PIDFILE) > /dev/null 2>&1 ; then
+            return 1
+    fi
+
+    if apache_conftest ; then
+            $APACHECTL start
+            apache_wait_start $?
+            return $?
+    else
+            return 2
+    fi
+}
+
+#
+# Function that stops the daemon/service
+#
+do_stop()
+{
+    # Return
+    #   0 if daemon has been stopped
+    #   1 if daemon was already stopped
+    #   2 if daemon could not be stopped
+    #   other if a failure occurred
+
+        local AP_RET=0
+
+        if pidof $DAEMON > /dev/null 2>&1 ; then
+                if [ -e $PIDFILE ] && pidof $DAEMON | tr ' ' '\n' | grep -w $(cat $PIDFILE) > /dev/null 2>&1 ; then
+                        AP_RET=2
+                else
+                        AP_RET=1
+                fi
+        else
+            AP_RET=0
+        fi
+
+        # AP_RET is:
+        # 0 if Apache (whichever) is not running
+        # 1 if Apache (whichever) is running
+        # 2 if Apache from the PIDFILE is running
+
+        if [ $AP_RET = 0 ] ; then
+                return 1
+        fi
+
+        if [ $AP_RET = 2 ] && apache_conftest ; then
+                $APACHECTL stop
+                apache_wait_stop $?
+                return $?
+        else
+                if [ $AP_RET = 2 ]; then
+                        kill $(pidof $DAEMON | tr ' ' '\n' | grep -w $(cat $PIDFILE))
+                        apache_wait_stop $?
+                        return $?
+                elif [ $AP_RET = 1 ] ; then
+                        return 2
+                fi
+        fi
+
+}
+
 case "$1" in
   start)
     echo -n "Starting web server: $NAME"
-    $APACHECTL $ARGS
+    do_start
+    case $? in
+        0|1)
+            echo .
+            exit 0
+            ;;
+        2)
+            echo failed
+            exit 1
+            ;;
+    esac
     ;;
 
   stop)
-    $APACHECTL stop
+    echo -n "Stopping web server: $NAME"
+    do_stop
+    case $? in
+        0|1)
+            echo .
+            exit 0
+            ;;
+        2)
+            echo failed
+            exit 1
+            ;;
+    esac
     ;;
 
   reload)
@@ -49,8 +196,18 @@ case "$1" in
     ;;
 
   restart)
-    $APACHECTL restart
-    exit $?
+    echo "Restarting web server: $NAME"
+    do_stop
+    case "$?" in
+        0|1)
+            do_start
+            exit $?
+            ;;
+        *)
+            # Failed to stop
+            exit 1
+            ;;
+    esac
     ;;
 
   force-reload)
-- 
1.9.5.msysgit.0