initscript: don't block system start-up by default

This commit should resolve complaints against pg_ctl -w usage from
initscript (see rhbz#800534 for more info).

The problem is that pg_ctl -w can block whole system startup too
long - until the server is fully ready to accept connections.  The
commit 8c7b2cd thus invented
basically bad approach for initscript.

Now, the "-w" option is used only if the PGSTARTWAIT is explicitly
set to 1 by administrator.  In this case, the PGSTARTTIMEOUT
numeric value (in seconds) is respected (or limit 30 seconds is
set by default).

Otherwise, if PGSTARTWAIT is unset (default), initscript keeps
checking only for the pidfile existence (at most PGSTARTTIMEOUT
seconds).  The hardwired 'sleep 2' command (activated before
8c7b2cd commit) is still not used - regular/default system
startup should be a bit faster than before.

* postgresql.init.in (start): Fix handling of PGDATA, PGPORT,
PGOPTS and PGSCLS - to respect special quoting characters inside,
we should escape the strings before passing those to command
evaluation.  Use printf %q as we use bash and we don't care too
much about portability.  Also, don't call postgresql-ctl with -w
option if PGSTARTWAIT is empty or undefined.  Implement pidfile
polling for the cases PGSTARTWAIT is unset.  Return success faster
if server is already running.
($PGSTARTWAIT): New env variable.
* postgresql-ctl.in: Don't parse $PGPORT into -o option as it is
not needed.  Unset PGPORT if the variable is empty - postgres
server would fail with empty value.
* configure.ac: Bump version to 3.3.
* NEWS: Document bugfixes.

Author: praiskup

NEWS

@@ -1,6 +1,20 @@
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-New in 3.1 version
+Bugfixes in 3.3 version
+
+* The PGPORT/PGOPTS/.. variables should be correctly forwarded down from
+  the initstcript into postgresql-ctl.
+
+* Initscript's 'start' function again reports success if daemon is already
+  running.
+
+New in 3.3 version
+
+* New option PGSTARTWAIT for sysvinit systems.
+
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+New in 3.2 version
 
 * The --new-systemd-unit option now cleans the recently created drop-in
   directory if something goes wrong.

configure.ac

@@ -1,5 +1,5 @@
 # Use the MAJ.MIN[~SUFF].  Note that X.X > X.X~SUFF!
-AC_INIT([postgresql-setup], [3.2], [[email protected]])
+AC_INIT([postgresql-setup], [3.3], [[email protected]])
 AC_CONFIG_AUX_DIR(auxdir)
 config_aux_dir=auxdir
 AC_SUBST([config_aux_dir])

postgresql-ctl.in

@@ -22,9 +22,10 @@
 # such extension, not the server itself).
 test -n "$PGSCLS" && source scl_source enable $PGSCLS
 
-port=()
-if test "$1" = "start" && test -n "$PGPORT"; then
-    port=(-o "-p $PGPORT")
-fi
+opts=()
+test "$1" = "start" && test -n "$PGOPTS" && opts=(-o "$PGOPTS")
 
-exec @bindir@/pg_ctl "$@" "${port[@]}"
+# cleanup possibly empty PGPORT
+test -z "$PGPORT" && unset PGPORT
+
+exec @bindir@/pg_ctl "$@" "${opts[@]}"

postgresql.init.in

@@ -117,11 +117,26 @@ start()
     # The maximum waiting time PGSTARTTIMEOUT is set to 30 second to not hold
     # the system too long.  See `man pg_ctl & -w option`.  This is not issue in
     # case of systemd.
+    #
+    # PGSTARTWAIT turns on waiting for server to become fully ready to accept
+    # connection.
+
+    # clean the variable if not set to 1
+    test x1 != x"$PGSTARTWAIT" && PGSTARTWAIT=
+
+    # success if already started (pg_ctl -w could fail later)
+    status -p "$pidfile" postgres &>/dev/null && {
+        success "$PSQL_START"
+        echo
+        exit 0
+    }
 
     run_cmd_as_dbadmin "\
-            PGSCLS='${PGSCLS}' \
-            @libexecdir@/postgresql-ctl start -D ${PGDATA} -s \
-                -w -t ${PGSTARTTIMEOUT-30}" \
+            PGSCLS=$(printf %q "$PGSCLS") \
+            PGOPTS=$(printf %q "$PGOPTS") \
+            PGPORT=$(printf %q "$PGPORT") \
+            @libexecdir@/postgresql-ctl start -D $(printf %q "$PGDATA") -s \
+                ${PGSTARTWAIT:+-w -t ${PGSTARTTIMEOUT:-30}}" \
             "$PGLOG" "$PGLOG"
 
     if test $? -ne 0; then
@@ -131,18 +146,41 @@ start()
         return
     fi
 
-	pid=`head -n 1 "$PGDATA/postmaster.pid" 2>/dev/null`
-	if [ "x$pid" != x ]
-	then
-		success "$PSQL_START"
-		touch "$lockfile"
-		echo $pid > "$pidfile"
-		echo
-	else
-		failure "$PSQL_START"
-		echo
-		script_result=1
-	fi
+    # pg_ctl succeed, now recognize the pid number
+
+    pid=
+    if test x1 != x"$PGSTARTWAIT" ; then
+        # We don't wait for the full postgresql server start.  In this case,
+        # wait for pidfile creation only.  This should take _very_ short time in
+        # most cases but on highly overloaded machines - several seconds may
+        # not be enough.  See rhbz#800534 and rhbz#1188942 for more info.
+        # Original waiting implementation by Jozef Mlích.
+
+        decounter=${PGSTARTTIMEOUT:-30}
+        while test "$decounter" -ge 0; do
+            pid=$(head -n 1 "$PGDATA/postmaster.pid" 2>/dev/null)
+
+            test "x$pid" != x && break
+
+            # pidfile does not exist yet, wait a sec more
+            decounter=$(( decounter - 1 ))
+            sleep 1
+        done
+    else
+        # pg_ctl -w succeed, pidfile must exist if everything is OK
+        pid=$(head -n 1 "$PGDATA/postmaster.pid" 2>/dev/null)
+    fi
+
+    if test "x$pid" != x; then
+        success "$PSQL_START"
+        touch "$lockfile"
+        echo "$pid" > "$pidfile"
+        echo
+    else
+        failure "$PSQL_START"
+        echo
+        script_result=1
+    fi
 }
 
 stop()