OCF resource agents: add rbd

Add a resource agent for mapping, unmapping and monitoring RBD devices.

Maps an RBD on start, unmaps it on stop. Checks "rbd showmapped"
output for monitoring whether the device is mapped, thus does not
rely on the ceph-rbdnamer udev magic to be enabled.

This RA is cloneable and essentially allows people to use RBD devices
as a drop-in replacement for
- iSCSI devices,
- host-based mirrored devices using md RAID-1,
- DRBD devices
in Pacemaker clusters.

2 files changed, 297 insertions, 1 deletions

diff --git a/src/ocf/Makefile.am b/src/ocf/Makefile.am
index 9be40ec05b6..569f3abeb74 100644
--- a/src/ocf/Makefile.am
+++ b/src/ocf/Makefile.am
@@ -9,7 +9,7 @@ ocfdir = $(prefix)/lib/ocf
 # The ceph provider directory
 radir = $(ocfdir)/resource.d/$(PACKAGE_NAME)
 
-ra_SCRIPTS = ceph
+ra_SCRIPTS = ceph rbd
 
 install-data-hook:
 	$(LN_S) ceph $(DESTDIR)$(radir)/osd
diff --git a/src/ocf/rbd.in b/src/ocf/rbd.in
new file mode 100644
index 00000000000..1cced93a64b
--- /dev/null
+++ b/src/ocf/rbd.in
@@ -0,0 +1,296 @@
+#!/bin/sh
+#
+#   OCF resource agent for mapping and unmapping
+#   RADOS Block Devices (RBDs)
+#
+#   License:      GNU Lesser General Public License (LGPL) 2.1
+#   (c) 2012 Florian Haas, hastexo
+#
+
+# Initialization:
+: ${OCF_FUNCTIONS_DIR=${OCF_ROOT}/lib/heartbeat}
+. ${OCF_FUNCTIONS_DIR}/ocf-shellfuncs
+
+# Convenience variables
+# When sysconfdir isn't passed in as a configure flag,
+# it's defined in terms of prefix
+prefix=@prefix@
+
+# Defaults
+OCF_RESKEY_pool_default="rbd"
+OCF_RESKEY_cephconf_default="@sysconfdir@/@PACKAGE_TARNAME@/@PACKAGE_TARNAME@.conf"
+: ${OCF_RESKEY_pool=${OCF_RESKEY_pool_default}}
+: ${OCF_RESKEY_cephconf=${OCF_RESKEY_cephconf_default}}
+
+rbd_meta_data() {
+    cat <<EOF
+<?xml version="1.0"?>
+<!DOCTYPE resource-agent SYSTEM "ra-api-1.dtd">
+<resource-agent name="rbd" version="0.1">
+  <version>0.1</version>
+  <longdesc lang="en">
+Manages RADOS Block Devices (RBDs) as a highly available
+resource. Maps and unmaps RBDs as needed.
+  </longdesc>
+  <shortdesc lang="en">Maps and unmaps RADOS Block Devices</shortdesc>
+  <parameters>
+    <parameter name="name" unique="0" required="1">
+      <longdesc lang="en">
+      Name of the RBD device.
+      </longdesc>
+      <shortdesc lang="en">RBD device name</shortdesc>
+      <content type="string"/>
+    </parameter>
+    <parameter name="pool" unique="0" required="0">
+      <longdesc lang="en">
+      Name of the RADOS pool where the RBD has been created
+      </longdesc>
+      <shortdesc lang="en">RADOS pool name</shortdesc>
+      <content type="string" default="${OCF_RESKEY_pool_default}"/>
+    </parameter>
+    <parameter name="snap" unique="0" required="0">
+      <longdesc lang="en">
+      Name of the device snapshot to map.
+      </longdesc>
+      <shortdesc lang="en">Snapshot name</shortdesc>
+      <content type="string"/>
+    </parameter>
+    <parameter name="cephconf" unique="0" required="0">
+      <longdesc lang="en">
+      Location of the Ceph configuration file
+      </longdesc>
+      <shortdesc lang="en">Ceph configuration file</shortdesc>
+      <content type="string" default="${OCF_RESKEY_cephconf_default}"/>
+    </parameter>
+    <parameter name="mon" unique="0" required="0">
+      <longdesc lang="en">
+      Address (or comma-separated list of addresses) of
+      monitor servers to connect to. Overrides values from
+      configuration file.
+      </longdesc>
+      <shortdesc lang="en">Monitor address(es)</shortdesc>
+      <content type="string"/>
+    </parameter>
+    <parameter name="user" unique="0" required="0">
+      <longdesc lang="en">
+      Username to use when mapping the device. Required
+      if Ceph authentication is enabled on the monitor.
+      </longdesc>
+      <shortdesc lang="en">Authentication username</shortdesc>
+      <content type="string"/>
+    </parameter>
+    <parameter name="secret" unique="0" required="0">
+      <longdesc lang="en">
+      File containing an authentication secret. Required
+      if Ceph authentication is enabled on the monitor.
+      </longdesc>
+      <shortdesc lang="en">Authentication secret file</shortdesc>
+      <content type="string"/>
+    </parameter>
+  </parameters>
+  <actions>
+    <action name="start"        timeout="20" />
+    <action name="stop"         timeout="20" />
+    <action name="monitor"      timeout="20"
+                                interval="10" depth="0" />
+    <action name="meta-data"    timeout="5" />
+    <action name="validate-all"   timeout="20" />
+  </actions>
+</resource-agent>
+EOF
+}
+
+rbd_usage() {
+        cat <<EOF
+usage: $0 {start|stop|status|monitor|validate-all|meta-data}
+
+Expects to have a fully populated OCF RA-compliant environment set.
+EOF
+}
+
+# rbd command wrapper: builds an option string for invoking RBD based
+# on resource parameters, and invokes rbd through ocf_run.
+do_rbd() {
+    local rbd_options
+
+    if [ -n "${OCF_RESKEY_cephconf}" ]; then
+        rbd_options="$rbd_options -c ${OCF_RESKEY_cephconf}"
+    fi
+    if [ -n "${OCF_RESKEY_mon}" ]; then
+        rbd_options="$rbd_options -m ${OCF_RESKEY_mon}"
+    fi
+
+    ocf_run rbd $rbd_options $@
+}
+
+# Convenience function that uses "rbd showmapped" to retrieve the
+# mapped device name from the pool, RBD name, and snapshot.
+find_rbd_dev() {
+    local sedpat
+
+    # Example output from "rbd showmapped" (tab separated):
+    # id        pool    image   snap    device
+    # 0         rbd     test    -       /dev/rbd0
+
+    # Build the sed pattern, substituting "-" for the snapshot name if
+    # it's unset
+    sedpat="[0-9]\+\t${OCF_RESKEY_pool}\t${OCF_RESKEY_name}\t${OCF_RESKEY_snap:--}\t\(/dev/rbd[0-9]\+\)"
+
+    # Run rbd showmapped, filter out the header line, then try to
+    # extract the device name
+    rbd showmapped | tail -n +2 | sed -n -e "s,$sedpat,\1,p"
+}
+
+rbd_validate_all() {
+    # Test for configuration errors first
+    if [ -z "$OCF_RESKEY_name" ]; then
+       ocf_log err 'Required parameter "name" is unset!'
+       exit $OCF_ERR_CONFIGURED
+    fi
+
+    # Test for required binaries
+    check_binary rbd
+
+    return $OCF_SUCCESS
+}
+
+rbd_monitor() {
+    local rc
+    local rbd_dev
+
+    if ! [ -d /sys/bus/rbd ]; then
+	ocf_log debug "rbd module is not loaded"
+	return $OCF_NOT_RUNNING
+    fi
+
+    rbd_dev=`find_rbd_dev`
+
+    if [ -z "$rbd_dev" ]; then
+        ocf_log debug "RBD device is unmapped"
+        rc=$OCF_NOT_RUNNING
+    elif [ -b "$rbd_dev" ]; then
+        ocf_log debug "RBD device is mapped to $rbd_dev"
+        rc=$OCF_SUCCESS
+    else
+        # Device is listed, but the corresponding path is not a block
+        # device.
+        ocf_log err "$rbd_dev is not a block device!"
+        rc=$OCF_ERR_GENERIC
+    fi
+
+    return $rc
+}
+
+rbd_start() {
+    local rbd_map_options
+    local rbd_name
+
+    # if resource is already running, bail out early
+    if rbd_monitor; then
+        ocf_log info "Resource is already running"
+        return $OCF_SUCCESS
+    fi
+
+    # actually start up the resource here (make sure to immediately
+    # exit with an $OCF_ERR_ error code if anything goes seriously
+    # wrong)
+
+    if [ ! -d /sys/bus/rbd ]; then
+        ocf_run modprobe -v rbd || exit $OCF_ERR_INSTALLED
+    fi
+
+    if [ -n "${OCF_RESKEY_user}" ]; then
+        rbd_map_options="--user ${OCF_RESKEY_user}"
+    fi
+    if [ -n "${OCF_RESKEY_secret}" ]; then
+        rbd_map_options="$rbd_map_options --secret ${OCF_RESKEY_secret}"
+    fi
+
+    rbd_name="${OCF_RESKEY_pool}/${OCF_RESKEY_name}"
+    if [ -n "${OCF_RESKEY_snap}" ]; then
+        rbd_name="$rbd_name@${OCF_RESKEY_snap}"
+    fi
+
+    do_rbd map $rbd_name $rbd_map_options || exit $OCF_ERR_GENERIC
+
+    # After the resource has been started, check whether it started up
+    # correctly. If the resource starts asynchronously, the agent may
+    # spin on the monitor function here -- if the resource does not
+    # start up within the defined timeout, the cluster manager will
+    # consider the start action failed
+    while ! rbd_monitor; do
+        ocf_log debug "Resource has not started yet, waiting"
+        sleep 1
+    done
+
+    # only return $OCF_SUCCESS if _everything_ succeeded as expected
+    return $OCF_SUCCESS
+}
+
+rbd_stop() {
+    local rc
+    local rbd_dev
+
+    rbd_monitor
+    rc=$?
+    case "$rc" in
+        "$OCF_SUCCESS")
+            # Currently running. Normal, expected behavior.
+            ocf_log debug "Resource is currently running"
+            ;;
+        "$OCF_NOT_RUNNING")
+            # Currently not running. Nothing to do.
+            ocf_log info "Resource is already stopped"
+            return $OCF_SUCCESS
+            ;;
+    esac
+
+    # actually shut down the resource here (make sure to immediately
+    # exit with an $OCF_ERR_ error code if anything goes seriously
+    # wrong)
+    rbd_dev=`find_rbd_dev`
+    do_rbd unmap $rbd_dev || exit $OCF_ERR_GENERIC
+
+    # After the resource has been stopped, check whether it shut down
+    # correctly. If the resource stops asynchronously, the agent may
+    # spin on the monitor function here -- if the resource does not
+    # shut down within the defined timeout, the cluster manager will
+    # consider the stop action failed
+    while rbd_monitor; do
+        ocf_log debug "Resource has not stopped yet, waiting"
+        sleep 1
+    done
+
+    # only return $OCF_SUCCESS if _everything_ succeeded as expected
+    return $OCF_SUCCESS
+
+}
+
+# Make sure meta-data and usage always succeed
+case $__OCF_ACTION in
+meta-data)      rbd_meta_data
+                exit $OCF_SUCCESS
+                ;;
+usage|help)     rbd_usage
+                exit $OCF_SUCCESS
+                ;;
+esac
+
+# Anything other than meta-data and usage must pass validation
+rbd_validate_all || exit $?
+
+# Translate each action into the appropriate function call
+case $__OCF_ACTION in
+start)          rbd_start;;
+stop)           rbd_stop;;
+status|monitor) rbd_monitor;;
+validate-all)   ;;
+*)              rbd_usage
+                exit $OCF_ERR_UNIMPLEMENTED
+                ;;
+esac
+rc=$?
+
+# The resource agent may optionally log a debug message
+ocf_log debug "${OCF_RESOURCE_INSTANCE} $__OCF_ACTION returned $rc"
+exit $rc