1 Ganeti customisation using hooks
2 ================================
4 Documents Ganeti version 2.7
11 In order to allow customisation of operations, Ganeti runs scripts in
12 sub-directories of ``@SYSCONFDIR@/ganeti/hooks``. These sub-directories
13 are named ``$hook-$phase.d``, where ``$phase`` is either ``pre`` or
14 ``post`` and ``$hook`` matches the directory name given for a hook (e.g.
15 ``cluster-verify-post.d`` or ``node-add-pre.d``).
17 This is similar to the ``/etc/network/`` structure present in Debian
18 for network interface handling.
23 For every operation, two sets of scripts are run:
25 - pre phase (for authorization/checking)
26 - post phase (for logging)
28 Also, for each operation, the scripts are run on one or more nodes,
29 depending on the operation type.
31 Note that, even though we call them scripts, we are actually talking
37 The *pre* scripts have a definite target: to check that the operation
38 is allowed given the site-specific constraints. You could have, for
39 example, a rule that says every new instance is required to exists in
40 a database; to implement this, you could write a script that checks
41 the new instance parameters against your database.
43 The objective of these scripts should be their return code (zero or
44 non-zero for success and failure). However, if they modify the
45 environment in any way, they should be idempotent, as failed
46 executions could be restarted and thus the script(s) run again with
47 exactly the same parameters.
49 Note that if a node is unreachable at the time a hooks is run, this
50 will not be interpreted as a deny for the execution. In other words,
51 only an actual error returned from a script will cause abort, and not
54 Therefore, if you want to guarantee that a hook script is run and
55 denies an action, it's best to put it on the master node.
60 These scripts should do whatever you need as a reaction to the
61 completion of an operation. Their return code is not checked (but
62 logged), and they should not depend on the fact that the *pre* scripts
68 The allowed names for the scripts consist of (similar to *run-parts*)
69 upper and lower case, digits, underscores and hyphens. In other words,
70 the regexp ``^[a-zA-Z0-9_-]+$``. Also, non-executable scripts will be
77 On a single node, the scripts in a directory are run in lexicographic
78 order (more exactly, the python string comparison order). It is
79 advisable to implement the usual *NN-name* convention where *NN* is a
82 For an operation whose hooks are run on multiple nodes, there is no
83 specific ordering of nodes with regard to hooks execution; you should
84 assume that the scripts are run in parallel on the target nodes
85 (keeping on each node the above specified ordering). If you need any
86 kind of inter-node synchronisation, you have to implement it yourself
92 The scripts will be run as follows:
94 - no command line arguments
96 - no controlling *tty*
98 - stdin is actually */dev/null*
100 - stdout and stderr are directed to files
102 - PATH is reset to :pyeval:`constants.HOOKS_PATH`
104 - the environment is cleared, and only ganeti-specific variables will
108 All information about the cluster is passed using environment
109 variables. Different operations will have sligthly different
110 environments, but most of the variables are common.
121 Adds a node to the cluster.
124 :env. vars: NODE_NAME, NODE_PIP, NODE_SIP, MASTER_CAPABLE, VM_CAPABLE
125 :pre-execution: all existing nodes
126 :post-execution: all nodes plus the new node
132 Removes a node from the cluster. On the removed node the hooks are
133 called during the execution of the operation and not after its
136 :directory: node-remove
137 :env. vars: NODE_NAME
138 :pre-execution: all existing nodes except the removed node
139 :post-execution: all existing nodes
144 Changes a node's parameters.
146 :directory: node-modify
147 :env. vars: MASTER_CANDIDATE, OFFLINE, DRAINED, MASTER_CAPABLE, VM_CAPABLE
148 :pre-execution: master node, the target node
149 :post-execution: master node, the target node
154 Relocate secondary instances from a node.
156 :directory: node-migrate
157 :env. vars: NODE_NAME
158 :pre-execution: master node
159 :post-execution: master node
162 Node group operations
163 ~~~~~~~~~~~~~~~~~~~~~
168 Adds a node group to the cluster.
170 :directory: group-add
171 :env. vars: GROUP_NAME
172 :pre-execution: master node
173 :post-execution: master node
178 Changes a node group's parameters.
180 :directory: group-modify
181 :env. vars: GROUP_NAME, NEW_ALLOC_POLICY
182 :pre-execution: master node
183 :post-execution: master node
188 Removes a node group from the cluster. Since the node group must be
189 empty for removal to succeed, the concept of "nodes in the group" does
190 not exist, and the hook is only executed in the master node.
192 :directory: group-remove
193 :env. vars: GROUP_NAME
194 :pre-execution: master node
195 :post-execution: master node
200 Renames a node group.
202 :directory: group-rename
203 :env. vars: OLD_NAME, NEW_NAME
204 :pre-execution: master node and all nodes in the group
205 :post-execution: master node and all nodes in the group
210 Evacuates a node group.
212 :directory: group-evacuate
213 :env. vars: GROUP_NAME, TARGET_GROUPS
214 :pre-execution: master node and all nodes in the group
215 :post-execution: master node and all nodes in the group
223 Adds a network to the cluster.
225 :directory: network-add
226 :env. vars: NETWORK_NAME, NETWORK_SUBNET, NETWORK_GATEWAY, NETWORK_SUBNET6,
227 NETWORK_GATEWAY6, NETWORK_MAC_PREFIX, NETWORK_TAGS
228 :pre-execution: master node
229 :post-execution: master node
234 Removes a network from the cluster.
236 :directory: network-remove
237 :env. vars: NETWORK_NAME
238 :pre-execution: master node
239 :post-execution: master node
244 Connects a network to a nodegroup.
246 :directory: network-connect
247 :env. vars: GROUP_NAME, NETWORK_NAME,
248 GROUP_NETWORK_MODE, GROUP_NETWORK_LINK,
249 NETWORK_SUBNET, NETWORK_GATEWAY, NETWORK_SUBNET6,
250 NETWORK_GATEWAY6, NETWORK_MAC_PREFIX, NETWORK_TAGS
251 :pre-execution: nodegroup nodes
252 :post-execution: nodegroup nodes
255 OP_NETWORK_DISCONNECT
256 +++++++++++++++++++++
258 Disconnects a network from a nodegroup.
260 :directory: network-disconnect
261 :env. vars: GROUP_NAME, NETWORK_NAME,
262 GROUP_NETWORK_MODE, GROUP_NETWORK_LINK,
263 NETWORK_SUBNET, NETWORK_GATEWAY, NETWORK_SUBNET6,
264 NETWORK_GATEWAY6, NETWORK_MAC_PREFIX, NETWORK_TAGS
265 :pre-execution: nodegroup nodes
266 :post-execution: nodegroup nodes
269 OP_NETWORK_SET_PARAMS
270 +++++++++++++++++++++
274 :directory: network-modify
275 :env. vars: NETWORK_NAME, NETWORK_SUBNET, NETWORK_GATEWAY, NETWORK_SUBNET6,
276 NETWORK_GATEWAY6, NETWORK_MAC_PREFIX, NETWORK_TAGS
277 :pre-execution: master node
278 :post-execution: master node
284 All instance operations take at least the following variables:
285 INSTANCE_NAME, INSTANCE_PRIMARY, INSTANCE_SECONDARY,
286 INSTANCE_OS_TYPE, INSTANCE_DISK_TEMPLATE, INSTANCE_MEMORY,
287 INSTANCE_DISK_SIZES, INSTANCE_VCPUS, INSTANCE_NIC_COUNT,
288 INSTANCE_NICn_IP, INSTANCE_NICn_BRIDGE, INSTANCE_NICn_MAC,
289 INSTANCE_NICn_NETWORK,
290 INSTANCE_NICn_NETWORK_UUID, INSTANCE_NICn_NETWORK_SUBNET,
291 INSTANCE_NICn_NETWORK_GATEWAY, INSTANCE_NICn_NETWORK_SUBNET6,
292 INSTANCE_NICn_NETWORK_GATEWAY6, INSTANCE_NICn_NETWORK_MAC_PREFIX,
293 INSTANCE_DISK_COUNT, INSTANCE_DISKn_SIZE, INSTANCE_DISKn_MODE.
295 The INSTANCE_NICn_* and INSTANCE_DISKn_* variables represent the
296 properties of the *n* -th NIC and disk, and are zero-indexed.
298 The INSTANCE_NICn_NETWORK_* variables are only passed if a NIC's network
299 parameter is set (that is if the NIC is associated to a network defined
306 Creates a new instance.
308 :directory: instance-add
309 :env. vars: ADD_MODE, SRC_NODE, SRC_PATH, SRC_IMAGES
310 :pre-execution: master node, primary and secondary nodes
311 :post-execution: master node, primary and secondary nodes
313 OP_INSTANCE_REINSTALL
314 +++++++++++++++++++++
316 Reinstalls an instance.
318 :directory: instance-reinstall
319 :env. vars: only the standard instance vars
320 :pre-execution: master node, primary and secondary nodes
321 :post-execution: master node, primary and secondary nodes
326 Exports the instance.
328 :directory: instance-export
329 :env. vars: EXPORT_MODE, EXPORT_NODE, EXPORT_DO_SHUTDOWN, REMOVE_INSTANCE
330 :pre-execution: master node, primary and secondary nodes
331 :post-execution: master node, primary and secondary nodes
338 :directory: instance-start
340 :pre-execution: master node, primary and secondary nodes
341 :post-execution: master node, primary and secondary nodes
348 :directory: instance-stop
350 :pre-execution: master node, primary and secondary nodes
351 :post-execution: master node, primary and secondary nodes
358 :directory: instance-reboot
359 :env. vars: IGNORE_SECONDARIES, REBOOT_TYPE, SHUTDOWN_TIMEOUT
360 :pre-execution: master node, primary and secondary nodes
361 :post-execution: master node, primary and secondary nodes
363 OP_INSTANCE_SET_PARAMS
364 ++++++++++++++++++++++
366 Modifies the instance parameters.
368 :directory: instance-modify
369 :env. vars: NEW_DISK_TEMPLATE, RUNTIME_MEMORY
370 :pre-execution: master node, primary and secondary nodes
371 :post-execution: master node, primary and secondary nodes
376 Failovers an instance. In the post phase INSTANCE_PRIMARY and
377 INSTANCE_SECONDARY refer to the nodes that were repectively primary
378 and secondary before failover.
380 :directory: instance-failover
381 :env. vars: IGNORE_CONSISTENCY, SHUTDOWN_TIMEOUT, OLD_PRIMARY, OLD_SECONDARY, NEW_PRIMARY, NEW_SECONDARY
382 :pre-execution: master node, secondary node
383 :post-execution: master node, primary and secondary nodes
388 Migrates an instance. In the post phase INSTANCE_PRIMARY and
389 INSTANCE_SECONDARY refer to the nodes that were repectively primary
390 and secondary before migration.
392 :directory: instance-migrate
393 :env. vars: MIGRATE_LIVE, MIGRATE_CLEANUP, OLD_PRIMARY, OLD_SECONDARY, NEW_PRIMARY, NEW_SECONDARY
394 :pre-execution: master node, primary and secondary nodes
395 :post-execution: master node, primary and secondary nodes
403 :directory: instance-remove
404 :env. vars: SHUTDOWN_TIMEOUT
405 :pre-execution: master node
406 :post-execution: master node, primary and secondary nodes
408 OP_INSTANCE_GROW_DISK
409 +++++++++++++++++++++
411 Grows the disk of an instance.
413 :directory: disk-grow
414 :env. vars: DISK, AMOUNT
415 :pre-execution: master node, primary and secondary nodes
416 :post-execution: master node, primary and secondary nodes
423 :directory: instance-rename
424 :env. vars: INSTANCE_NEW_NAME
425 :pre-execution: master node, primary and secondary nodes
426 :post-execution: master node, primary and secondary nodes
431 Move an instance by data-copying.
433 :directory: instance-move
434 :env. vars: TARGET_NODE, SHUTDOWN_TIMEOUT
435 :pre-execution: master node, primary and target nodes
436 :post-execution: master node, primary and target nodes
438 OP_INSTANCE_RECREATE_DISKS
439 ++++++++++++++++++++++++++
441 Recreate an instance's missing disks.
443 :directory: instance-recreate-disks
444 :env. vars: only the standard instance vars
445 :pre-execution: master node, primary and secondary nodes
446 :post-execution: master node, primary and secondary nodes
448 OP_INSTANCE_REPLACE_DISKS
449 +++++++++++++++++++++++++
451 Replace the disks of an instance.
453 :directory: mirrors-replace
454 :env. vars: MODE, NEW_SECONDARY, OLD_SECONDARY
455 :pre-execution: master node, primary and new secondary nodes
456 :post-execution: master node, primary and new secondary nodes
458 OP_INSTANCE_CHANGE_GROUP
459 ++++++++++++++++++++++++
461 Moves an instance to another group.
463 :directory: instance-change-group
464 :env. vars: TARGET_GROUPS
465 :pre-execution: master node
466 :post-execution: master node
475 This hook is called via a special "empty" LU right after cluster
478 :directory: cluster-init
481 :post-execution: master node
486 The post phase of this hook is called during the execution of destroy
487 operation and not after its completion.
489 :directory: cluster-destroy
492 :post-execution: master node
494 OP_CLUSTER_VERIFY_GROUP
495 +++++++++++++++++++++++
497 Verifies all nodes in a group. This is a special LU with regard to
498 hooks, as the result of the opcode will be combined with the result of
499 post-execution hooks, in order to allow administrators to enhance the
500 cluster verification procedure.
502 :directory: cluster-verify
503 :env. vars: CLUSTER, MASTER, CLUSTER_TAGS, NODE_TAGS_<name>
505 :post-execution: all nodes in a group
512 :directory: cluster-rename
514 :pre-execution: master-node
515 :post-execution: master-node
517 OP_CLUSTER_SET_PARAMS
518 +++++++++++++++++++++
520 Modifies the cluster parameters.
522 :directory: cluster-modify
523 :env. vars: NEW_VG_NAME
524 :pre-execution: master node
525 :post-execution: master node
527 Virtual operation :pyeval:`constants.FAKE_OP_MASTER_TURNUP`
528 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
530 This doesn't correspond to an actual op-code, but it is called when the
531 master IP is activated.
533 :directory: master-ip-turnup
534 :env. vars: MASTER_NETDEV, MASTER_IP, MASTER_NETMASK, CLUSTER_IP_VERSION
535 :pre-execution: master node
536 :post-execution: master node
538 Virtual operation :pyeval:`constants.FAKE_OP_MASTER_TURNDOWN`
539 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
541 This doesn't correspond to an actual op-code, but it is called when the
542 master IP is deactivated.
544 :directory: master-ip-turndown
545 :env. vars: MASTER_NETDEV, MASTER_IP, MASTER_NETMASK, CLUSTER_IP_VERSION
546 :pre-execution: master node
547 :post-execution: master node
553 The following operations are no longer present or don't execute hooks
554 anymore in Ganeti 2.0:
558 - OP_INSTANCE_ADD_MDDRBD
559 - OP_INSTANCE_REMOVE_MDDRBD
562 Environment variables
563 ---------------------
565 Note that all variables listed here are actually prefixed with *GANETI_*
566 in order to provide a clear namespace. In addition, post-execution
567 scripts receive another set of variables, prefixed with *GANETI_POST_*,
568 representing the status after the opcode executed.
573 This is the list of environment variables supported by all operations:
576 Documents the hooks interface version. In case this doesnt match
577 what the script expects, it should not run. The documents conforms
581 One of *PRE* or *POST* denoting which phase are we in.
590 One of the *OP_* values from the list of operations.
593 One of ``INSTANCE``, ``NODE``, ``CLUSTER``.
596 The path to the Ganeti configuration directory (to read, for
597 example, the *ssconf* files).
600 Specialised variables
601 ~~~~~~~~~~~~~~~~~~~~~
603 This is the list of variables which are specific to one or more
607 IP version of the master IP (4 or 6)
610 The name of the instance which is the target of the operation.
612 INSTANCE_BE_x,y,z,...
613 Instance BE params. There is one variable per BE param. For instance, GANETI_INSTANCE_BE_auto_balance
615 INSTANCE_DISK_TEMPLATE
616 The disk type for the instance.
619 The new disk type for the instance.
622 The number of disks for the instance.
625 The size of disk *n* for the instance.
628 Either *rw* for a read-write disk or *ro* for a read-only one.
630 INSTANCE_HV_x,y,z,...
631 Instance hypervisor options. There is one variable per option. For instance, GANETI_INSTANCE_HV_use_bootloader
634 The instance hypervisor.
637 The number of NICs for the instance.
640 The bridge to which the *n* -th NIC of the instance is attached.
643 The IP (if any) of the *n* -th NIC of the instance.
646 The MAC address of the *n* -th NIC of the instance.
649 The mode of the *n* -th NIC of the instance.
652 The name of the instance OS.
655 The name of the node which is the primary for the instance. Note that
656 for migrations/failovers, you shouldn't rely on this variable since
657 the nodes change during the exectution, but on the
658 OLD_PRIMARY/NEW_PRIMARY values.
661 Space-separated list of secondary nodes for the instance. Note that
662 for migrations/failovers, you shouldn't rely on this variable since
663 the nodes change during the exectution, but on the
664 OLD_SECONDARY/NEW_SECONDARY values.
667 The memory size (in MiBs) of the instance.
670 The number of virtual CPUs for the instance.
673 The run status of the instance.
676 Whether a node is capable of being promoted to master.
679 Whether the node can host instances.
682 Network device of the master IP
688 Netmask of the master IP
691 A space-delimited list of the instance's tags.
694 The target node of this operation (not the node on which the hook
698 The primary IP of the target node (the one over which inter-node
699 communication is done).
702 The secondary IP of the target node (the one over which drbd
703 replication is done). This can be equal to the primary ip, in case
704 the cluster is not dual-homed.
707 This is provided by some operations when the user gave this flag.
710 The user has specified this flag. It is used when failing over
711 instances in case the primary node is down.
714 The mode of the instance create: either *create* for create from
715 scratch or *import* for restoring from an exported image.
717 SRC_NODE, SRC_PATH, SRC_IMAGE
718 In case the instance has been added by import, these variables are
719 defined and point to the source node, source path (the directory
720 containing the image and the config file) and the source disk image
724 The name of the node on which the new mirror component is being
725 added (for replace disk). This can be the name of the current
726 secondary, if the new mirror is on the same secondary. For
727 migrations/failovers, this is the old primary node.
730 The name of the old secondary in the replace-disks command. Note that
731 this can be equal to the new secondary if the secondary node hasn't
732 actually changed. For migrations/failovers, this is the new primary
735 OLD_PRIMARY, NEW_PRIMARY
736 For migrations/failovers, the old and respectively new primary
737 nodes. These two mirror the NEW_SECONDARY/OLD_SECONDARY variables
740 The instance export mode. Either "remote" or "local".
743 The node on which the exported image of the instance was done.
746 This variable tells if the instance has been shutdown or not while
747 doing the export. In the "was shutdown" case, it's likely that the
748 filesystem is consistent, whereas in the "did not shutdown" case,
749 the filesystem would need a check (journal replay or full fsck) in
750 order to guarantee consistency.
753 Whether the instance was removed from the node.
756 Amount of time to wait for the instance to shutdown.
759 Amount of time to wait before aborting the op.
762 Old/new name of the node group.
765 The name of the node group.
768 The new allocation policy for the node group.
771 The list of cluster tags, space separated.
774 The list of tags for node *<name>*, space separated.
779 The startup of an instance will pass this environment to the hook
782 GANETI_CLUSTER=cluster1.example.com
783 GANETI_DATA_DIR=/var/lib/ganeti
785 GANETI_HOOKS_PATH=instance-start
786 GANETI_HOOKS_PHASE=post
787 GANETI_HOOKS_VERSION=2
788 GANETI_INSTANCE_DISK0_MODE=rw
789 GANETI_INSTANCE_DISK0_SIZE=128
790 GANETI_INSTANCE_DISK_COUNT=1
791 GANETI_INSTANCE_DISK_TEMPLATE=drbd
792 GANETI_INSTANCE_MEMORY=128
793 GANETI_INSTANCE_NAME=instance2.example.com
794 GANETI_INSTANCE_NIC0_BRIDGE=xen-br0
795 GANETI_INSTANCE_NIC0_IP=
796 GANETI_INSTANCE_NIC0_MAC=aa:00:00:a5:91:58
797 GANETI_INSTANCE_NIC_COUNT=1
798 GANETI_INSTANCE_OS_TYPE=debootstrap
799 GANETI_INSTANCE_PRIMARY=node3.example.com
800 GANETI_INSTANCE_SECONDARY=node5.example.com
801 GANETI_INSTANCE_STATUS=down
802 GANETI_INSTANCE_VCPUS=1
803 GANETI_MASTER=node1.example.com
804 GANETI_OBJECT_TYPE=INSTANCE
805 GANETI_OP_CODE=OP_INSTANCE_STARTUP
806 GANETI_OP_TARGET=instance2.example.com
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