[files/image_config]: update logrotate config for swss

files/image_config/logrotate/logrotate.d/rsyslog

@@ -34,8 +34,6 @@
 /var/log/telemetry.log
 /var/log/quagga/bgpd.log
 /var/log/quagga/zebra.log
-/var/log/swss/sairedis.rec
-/var/log/swss/swss.rec
 {
     size 1M
     rotate 5000
@@ -95,3 +93,66 @@
         fi
     endscript
 }
+
+
+/var/log/swss/sairedis.rec
+/var/log/swss/swss.rec
+{
+    size 20M
+    rotate 20
+    missingok
+    notifempty
+    compress
+    delaycompress
+    nosharedscripts
+    prerotate
+        # Adjust NUM_LOGS_TO_ROTATE to reflect number of log files that trigger this block specified above
+        NUM_LOGS_TO_ROTATE=8
+
+        # Adjust LOG_FILE_ROTATE_SIZE_KB to reflect the "size" parameter specified above, in kB
+        LOG_FILE_ROTATE_SIZE_KB=1024
+
+        # Reserve space for btmp, wtmp, dpkg.log, monit.log, etc., as well as logs that
+        # should be disabled, just in case they get created and rotated
+        RESERVED_SPACE_KB=4096
+
+        VAR_LOG_SIZE_KB=$(df -k /var/log | sed -n 2p | awk '{ print $2 }')
+
+        # Limit usable space to 90% of the partition minus the reserved space for other logs
+        USABLE_SPACE_KB=$(( (VAR_LOG_SIZE_KB * 90 / 100) - RESERVED_SPACE_KB))
+
+        # Set our threshold so as to maintain enough space to write all logs from empty to full
+        # Most likely, some logs will have non-zero size when this is called, so this errs on the side
+        # of caution, giving us a bit of a cushion if a log grows quickly and passes its rotation size
+        THRESHOLD_KB=$((USABLE_SPACE_KB - (NUM_LOGS_TO_ROTATE * LOG_FILE_ROTATE_SIZE_KB * 2)))
+
+        while true; do
+            USED_KB=$(du -s /var/log | awk '{ print $1; }')
+
+            if [ $USED_KB -lt $THRESHOLD_KB ]; then
+                break
+            else
+                OLDEST_ARCHIVE_FILE=$(find /var/log -type f -printf '%T+ %p\n' | grep -E '.+\.[0-9]+(\.gz)?$' | sort | head -n 1 | awk '{ print $2; }')
+
+                if [ -z "$OLDEST_ARCHIVE_FILE" ]; then
+                    logger -p syslog.err -t "logrotate" "No archive file to delete -- potential for filling up /var/log partition!"
+                    break
+                fi
+
+                logger -p syslog.info -t "logrotate" "Deleting archive file $OLDEST_ARCHIVE_FILE to free up space"
+                rm -rf "$OLDEST_ARCHIVE_FILE"
+            fi
+        done
+    endscript
+    postrotate
+        if [ $(echo $1 | grep -c "/var/log/swss/") -gt 0 ]; then
+            pgrep -x orchagent | xargs /bin/kill -HUP 2>/dev/null || true
+        else
+            # Calling kill directly instead of 'service rsyslog rotate >/dev/null' due
+            # to bug in init-system-helpers. Bug has apparently been fixed in v1.47.
+            # However, Debian Jessie is still using v1.22.
+            # See https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=672218
+            kill -HUP $(cat /var/run/rsyslogd.pid)
+        fi
+    endscript
+}