beautify runners.sh

Cherry-picked from StackStorm/st2-packages@7661c69

st2actions/bin/runners.sh

@@ -1,52 +1,57 @@
 #!/bin/sh
 
-INITCOMM=$(cat /proc/1/comm)
-SYSTEMDCTL=/bin/systemctl
-UPSTARTCTL=/sbin/initctl
-SPAWNSVC=st2actionrunner
-WORKERSVC=st2actionrunner-worker
-# Set default number of workers
+# Default number of workers
 WORKERS="${WORKERS:-10}"
 
-## Use running init system detection criterias
-#
-if [ -d /run/systemd/system ]; then
-  # systemd is running
-  sv=systemd
-  svbin=$SYSTEMDCTL
-elif [ "$INITCOMM" = init ] && ($UPSTARTCTL version 2>&1) &&
-        [ -f /etc/init/$WORKERSVC.conf ]; then
-  # init is running and upstart has been detected
-  sv=upstart
-  svbin=$UPSTARTCTL
-else
-  # In all other cases which may apply to older debians, redhats and
-  # centos, amazon etc.
-  sv=sysv
-  svbin=/etc/init.d/$WORKERSVC
-  if [ ! -x $svbin ]; then
-    >&2 echo "Init file not found: $svbin"
-    >&2 echo "Unknown platform, we support ONLY debian, systemd and sysv!"
-    exit 99
+# Choose init system to perform actions with a service.
+choose_sysinit() {
+  local service="$1" svinit="sysv"
+  if [ -d /run/systemd/system ]; then
+    svinit=systemd
+  elif [ "$(cat /proc/1/comm)" = init ] && [ -f /etc/init/${service}.conf ] &&
+         (/sbin/initctl version 2>&1 | grep -q upstart); then
+    svinit=upstart
+  else
+    if [ ! -x /etc/init.d/${service} ]; then
+      >&2 echo "Supported init systems: systemd, upstart and sysv"
+      >&2 echo "/etc/init.d/${service} not found or disabled"
+      exit 99
+    fi
   fi
-fi
+  echo $svinit
+}
 
-## Spwan workers
-#
-action="$1"; shift;
-rs=0
-i=1
-while [ $i -le $WORKERS ]; do
-  if [ $sv = systemd ]; then
-    $svbin $action $SPAWNSVC@$i
-  elif [ $sv = upstart ]; then
-    $svbin $action $WORKERSVC WORKERID=$i
-  elif [ $sv = sysv ]; then
-    WORKERID=$i $svbin $action
-  fi
-  cmdrs=$?
-  [ $cmdrs -gt 0 ] && rs=$cmdrs
-  i=`expr $i + 1`
-done
+# Perform service action over the given number of workers.
+spawn_workers() {
+  local action=$1
+  local init= seq=$(eval printf '%g\\n' {1..$WORKERS})
+
+  # Choose init system and exit if it's not supported.
+  init=$(choose_sysinit st2actionrunner)
+  [ $? -gt 0 ] && exit $?
+
+  case $init in
+    systemd)
+      echo "$seq" | xargs -I{} /bin/systemctl $action \
+          st2actionrunner@{}
+      ;;
+    upstart)
+      echo "$seq" | xargs -I{} /sbin/initctl $action \
+          st2actionrunner-worker WORKERID={}
+      ;;
+    sysv)
+      echo "$seq" | xargs -I{} /bin/sh -c \
+          "WORKERID={} /etc/init.d/st2actionrunner-worker $action"
+      ;;
+  esac
+  # return 1 in case if xargs failed any invoked commands.
+  [ $? -ge 123 ] && return 1 || return $?
+}
+
+# Perform service action on all actionrunners
+if [ -z "$1" ]; then
+  echo >&2 "Usage: $0 action"
+  exit 99
+fi
 
-exit $rs
+spawn_workers $1