Improve log file handling:

* Elimiate subshells to produce logfiles (fixes bug 885091)
* Clean up log files older than 7 days (default)
* Append date/time to specified log file name
* Default LOGFILE='', now must set to get logging

This changes the default behaviour of stack.sh to not write a log file
unless LOGFILE is set.

Change-Id: I5d3fb65e12ccdb52fca5a41ee8f5777c046cd375

stack.sh

@@ -390,8 +390,31 @@ read_password SERVICE_TOKEN "ENTER A SERVICE_TOKEN TO USE FOR THE SERVICE ADMIN
 # Horizon currently truncates usernames and passwords at 20 characters
 read_password ADMIN_PASSWORD "ENTER A PASSWORD TO USE FOR HORIZON AND KEYSTONE (20 CHARS OR LESS)."
 
-LOGFILE=${LOGFILE:-"$PWD/stack.sh.$$.log"}
+# Log files
-(
+# ---------
+
+# Set up logging for stack.sh
+# Set LOGFILE to turn on logging
+# We append '.xxxxxxxx' to the given name to maintain history
+# where xxxxxxxx is a representation of the date the file was created
+if [[ -n "$LOGFILE" ]]; then
+    # First clean up old log files.  Use the user-specified LOGFILE
+    # as the template to search for, appending '.*' to match the date
+    # we added on earlier runs.
+    LOGDAYS=${LOGDAYS:-7}
+    LOGDIR=$(dirname "$LOGFILE")
+    LOGNAME=$(basename "$LOGFILE")
+    find $LOGDIR -maxdepth 1 -name $LOGNAME.\* -mtime +$LOGDAYS -exec rm {} \;
+
+    TIMESTAMP_FORMAT=${TIMESTAMP_FORMAT:-"%F-%H%M%S"}
+    LOGFILE=$LOGFILE.$(date "+$TIMESTAMP_FORMAT")
+    # Redirect stdout/stderr to tee to write the log file
+    exec 1> >( tee "${LOGFILE}" ) 2>&1
+    echo "stack.sh log $LOGFILE"
+    # Specified logfile name always links to the most recent log
+    ln -sf $LOGFILE $LOGDIR/$LOGNAME
+fi
+
 # So that errors don't compound we exit on any errors so you see only the
 # first error that occurred.
 trap failed ERR
@@ -1403,13 +1426,8 @@ fi
 # Fin
 # ===
 
+set +o xtrace
 
-) 2>&1 | tee "${LOGFILE}"
-
-# Check that the left side of the above pipe succeeded
-for ret in "${PIPESTATUS[@]}"; do [ $ret -eq 0 ] || exit $ret; done
-
-(
 # Using the cloud
 # ===============
 
@@ -1436,5 +1454,3 @@ echo "This is your host ip: $HOST_IP"
 
 # Indicate how long this took to run (bash maintained variable 'SECONDS')
 echo "stack.sh completed in $SECONDS seconds."
-
-) | tee -a "$LOGFILE"