Merge "xenapi: script to rotate the guest logs"

1 files changed, 62 insertions, 0 deletions

diff --git a/tools/xenserver/rotate_xen_guest_logs.sh b/tools/xenserver/rotate_xen_guest_logs.sh
new file mode 100755
index 000000000..0e6c7d6ea
--- /dev/null
+++ b/tools/xenserver/rotate_xen_guest_logs.sh
@@ -0,0 +1,62 @@
+#!/bin/bash
+set -eux
+
+# Script to rotate console logs
+#
+# Should be run on Dom0, with cron, every minute:
+# * * * * * /root/rotate_xen_guest_logs.sh
+#
+# Should clear out the guest logs on every boot
+# because the domain ids may get re-used for a
+# different tenant after the reboot
+#
+# /var/log/xen/guest should be mounted into a
+# small loopback device to stop any guest being
+# able to fill dom0 file system
+
+log_dir="/var/log/xen/guest"
+kb=1024
+max_size_bytes=$(($kb*$kb))
+truncated_size_bytes=$((5*$kb))
+list_domains=/opt/xensource/bin/list_domains
+
+log_file_base="${log_dir}/console."
+tmp_file_base="${log_dir}/tmp.console."
+
+# Ensure logging is setup correctly for all domains
+xenstore-write /local/logconsole/@ "${log_file_base}%d"
+
+# Move logs we want to keep
+domains=$($list_domains | sed '/^id*/d' | sed 's/|.*|.*$//g' | xargs)
+for i in $domains; do
+    log="${log_file_base}$i"
+    tmp="${tmp_file_base}$i"
+    mv $log $tmp || true
+done
+
+# Delete all console logs,
+# mostly to remove logs from recently killed domains
+rm -f ${log_dir}/console.*
+
+# Reload domain list, in case it changed
+# (note we may have just deleted a new console log)
+domains=$($list_domains | sed '/^id*/d' | sed 's/|.*|.*$//g' | xargs)
+for i in $domains; do
+    log="${log_file_base}$i"
+    tmp="${tmp_file_base}$i"
+    size=$(stat -c%s "$tmp")
+
+    # Trim the log if required
+    if [ "$size" -gt "$max_size_bytes" ]; then
+        tail -c $truncated_size_bytes $tmp > $log || true
+    else
+        mv $tmp $log || true
+    fi
+
+    # Notify xen that it needs to reload the file
+    xenstore-write /local/logconsole/$i $log
+    xenstore-rm /local/logconsole/$i
+done
+
+# Delete all the tmp files
+rm -f ${tmp_file_base}* || true