Add core dump snapshot handler script

[lttng-tools.git] / extras / core-handler / handler.sh

diff --git a/extras/core-handler/handler.sh b/extras/core-handler/handler.sh
new file mode 100755 (executable)
index 0000000..3026e52
--- /dev/null
+++ b/extras/core-handler/handler.sh
@@ -0,0 +1,72 @@
+#!/bin/sh
+#
+# Copyright (C) 2013 - Christian Babeux <christian.babeux@efficios.com>
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; only version 2
+# of the License.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+#
+
+# System binaries paths.
+CAT_BIN="cat"
+PGREP_BIN="pgrep"
+MKDIR_BIN="mkdir"
+LTTNG_BIN="lttng"
+
+# Core file settings.
+CORE_PATH="/tmp/lttng/core"
+CORE_PREFIX="core"
+
+# Folder where to save snapshot output.
+# Can also be a remote URI.
+SNAPSHOT_PATH="/tmp/lttng/snapshot"
+SNAPSHOT_OUTPUT="file://${SNAPSHOT_PATH}"
+
+# Sessiond binary name.
+SESSIOND_BIN_NAME="lttng-sessiond"
+
+# Core specifiers, see man core(5)
+
+p=$1 # PID of dumped process
+u=$2 # (numeric) real UID of dumped process
+g=$3 # (numeric) real GID of dumped process
+s=$4 # number of signal causing dump
+t=$5 # time of dump, expressed as seconds since the Epoch,
+     # 1970-01-01 00:00:00 +0000 (UTC)
+h=$6 # hostname (same as nodename returned by uname(2))
+e=$7 # executable filename (without path prefix)
+E=$8 # pathname of executable, with slashes ('/') replaced
+     # by exclamation marks ('!').
+c=$9 # core file size soft resource limit of crashing process
+     # (since Linux 2.6.24)
+
+# Save core dump from stdin.
+$MKDIR_BIN -p "${CORE_PATH}"
+$CAT_BIN - > "${CORE_PATH}/${CORE_PREFIX}.$p"
+
+# Optional, chain core dump handler with original systemd script.
+#$CAT_BIN - | /usr/lib/systemd/systemd-coredump $p $u $g $s $t $e
+
+# TODO: Checking for a sessiond lockfile would be more appropriate.
+if $PGREP_BIN -u root "${SESSIOND_BIN_NAME}" > /dev/null 2>&1
+then
+    # Since we are called via the kernel coredump mechanism, we need to
+    # setup our environment manually.
+    #
+    # The lttng command line tool lookup $HOME to adjust the .lttngrc
+    # path. This is useful to have automatic session name lookup.
+    export HOME="/root"
+    $MKDIR_BIN -p "${SNAPSHOT_PATH}"
+    $LTTNG_BIN snapshot add-output "${SNAPSHOT_OUTPUT}" > /dev/null 2>&1
+    $LTTNG_BIN snapshot record > /dev/null 2>&1
+fi