1 Ganeti customisation using hooks
2 ================================
4 Documents Ganeti version 2.6
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_TYPE, 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_TYPE, 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_TYPE, 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_TYPE, 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_DISK_COUNT, INSTANCE_DISKn_SIZE, INSTANCE_DISKn_MODE.
291 The INSTANCE_NICn_* and INSTANCE_DISKn_* variables represent the
292 properties of the *n* -th NIC and disk, and are zero-indexed.
298 Creates a new instance.
300 :directory: instance-add
301 :env. vars: ADD_MODE, SRC_NODE, SRC_PATH, SRC_IMAGES
302 :pre-execution: master node, primary and secondary nodes
303 :post-execution: master node, primary and secondary nodes
305 OP_INSTANCE_REINSTALL
306 +++++++++++++++++++++
308 Reinstalls an instance.
310 :directory: instance-reinstall
311 :env. vars: only the standard instance vars
312 :pre-execution: master node, primary and secondary nodes
313 :post-execution: master node, primary and secondary nodes
318 Exports the instance.
320 :directory: instance-export
321 :env. vars: EXPORT_MODE, EXPORT_NODE, EXPORT_DO_SHUTDOWN, REMOVE_INSTANCE
322 :pre-execution: master node, primary and secondary nodes
323 :post-execution: master node, primary and secondary nodes
330 :directory: instance-start
332 :pre-execution: master node, primary and secondary nodes
333 :post-execution: master node, primary and secondary nodes
340 :directory: instance-stop
342 :pre-execution: master node, primary and secondary nodes
343 :post-execution: master node, primary and secondary nodes
350 :directory: instance-reboot
351 :env. vars: IGNORE_SECONDARIES, REBOOT_TYPE, SHUTDOWN_TIMEOUT
352 :pre-execution: master node, primary and secondary nodes
353 :post-execution: master node, primary and secondary nodes
355 OP_INSTANCE_SET_PARAMS
356 ++++++++++++++++++++++
358 Modifies the instance parameters.
360 :directory: instance-modify
361 :env. vars: NEW_DISK_TEMPLATE, RUNTIME_MEMORY
362 :pre-execution: master node, primary and secondary nodes
363 :post-execution: master node, primary and secondary nodes
368 Failovers an instance. In the post phase INSTANCE_PRIMARY and
369 INSTANCE_SECONDARY refer to the nodes that were repectively primary
370 and secondary before failover.
372 :directory: instance-failover
373 :env. vars: IGNORE_CONSISTENCY, SHUTDOWN_TIMEOUT, OLD_PRIMARY, OLD_SECONDARY, NEW_PRIMARY, NEW_SECONDARY
374 :pre-execution: master node, secondary node
375 :post-execution: master node, primary and secondary nodes
380 Migrates an instance. In the post phase INSTANCE_PRIMARY and
381 INSTANCE_SECONDARY refer to the nodes that were repectively primary
382 and secondary before migration.
384 :directory: instance-migrate
385 :env. vars: MIGRATE_LIVE, MIGRATE_CLEANUP, OLD_PRIMARY, OLD_SECONDARY, NEW_PRIMARY, NEW_SECONDARY
386 :pre-execution: master node, secondary node
387 :post-execution: master node, primary and secondary nodes
395 :directory: instance-remove
396 :env. vars: SHUTDOWN_TIMEOUT
397 :pre-execution: master node
398 :post-execution: master node, primary and secondary nodes
400 OP_INSTANCE_GROW_DISK
401 +++++++++++++++++++++
403 Grows the disk of an instance.
405 :directory: disk-grow
406 :env. vars: DISK, AMOUNT
407 :pre-execution: master node, primary and secondary nodes
408 :post-execution: master node, primary and secondary nodes
415 :directory: instance-rename
416 :env. vars: INSTANCE_NEW_NAME
417 :pre-execution: master node, primary and secondary nodes
418 :post-execution: master node, primary and secondary nodes
423 Move an instance by data-copying.
425 :directory: instance-move
426 :env. vars: TARGET_NODE, SHUTDOWN_TIMEOUT
427 :pre-execution: master node, primary and target nodes
428 :post-execution: master node, primary and target nodes
430 OP_INSTANCE_RECREATE_DISKS
431 ++++++++++++++++++++++++++
433 Recreate an instance's missing disks.
435 :directory: instance-recreate-disks
436 :env. vars: only the standard instance vars
437 :pre-execution: master node, primary and secondary nodes
438 :post-execution: master node, primary and secondary nodes
440 OP_INSTANCE_REPLACE_DISKS
441 +++++++++++++++++++++++++
443 Replace the disks of an instance.
445 :directory: mirrors-replace
446 :env. vars: MODE, NEW_SECONDARY, OLD_SECONDARY
447 :pre-execution: master node, primary and new secondary nodes
448 :post-execution: master node, primary and new secondary nodes
450 OP_INSTANCE_CHANGE_GROUP
451 ++++++++++++++++++++++++
453 Moves an instance to another group.
455 :directory: instance-change-group
456 :env. vars: TARGET_GROUPS
457 :pre-execution: master node
458 :post-execution: master node
467 This hook is called via a special "empty" LU right after cluster
470 :directory: cluster-init
473 :post-execution: master node
478 The post phase of this hook is called during the execution of destroy
479 operation and not after its completion.
481 :directory: cluster-destroy
484 :post-execution: master node
486 OP_CLUSTER_VERIFY_GROUP
487 +++++++++++++++++++++++
489 Verifies all nodes in a group. This is a special LU with regard to
490 hooks, as the result of the opcode will be combined with the result of
491 post-execution hooks, in order to allow administrators to enhance the
492 cluster verification procedure.
494 :directory: cluster-verify
495 :env. vars: CLUSTER, MASTER, CLUSTER_TAGS, NODE_TAGS_<name>
497 :post-execution: all nodes in a group
504 :directory: cluster-rename
506 :pre-execution: master-node
507 :post-execution: master-node
509 OP_CLUSTER_SET_PARAMS
510 +++++++++++++++++++++
512 Modifies the cluster parameters.
514 :directory: cluster-modify
515 :env. vars: NEW_VG_NAME
516 :pre-execution: master node
517 :post-execution: master node
519 Virtual operation :pyeval:`constants.FAKE_OP_MASTER_TURNUP`
520 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
522 This doesn't correspond to an actual op-code, but it is called when the
523 master IP is activated.
525 :directory: master-ip-turnup
526 :env. vars: MASTER_NETDEV, MASTER_IP, MASTER_NETMASK, CLUSTER_IP_VERSION
527 :pre-execution: master node
528 :post-execution: master node
530 Virtual operation :pyeval:`constants.FAKE_OP_MASTER_TURNDOWN`
531 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
533 This doesn't correspond to an actual op-code, but it is called when the
534 master IP is deactivated.
536 :directory: master-ip-turndown
537 :env. vars: MASTER_NETDEV, MASTER_IP, MASTER_NETMASK, CLUSTER_IP_VERSION
538 :pre-execution: master node
539 :post-execution: master node
545 The following operations are no longer present or don't execute hooks
546 anymore in Ganeti 2.0:
550 - OP_INSTANCE_ADD_MDDRBD
551 - OP_INSTANCE_REMOVE_MDDRBD
554 Environment variables
555 ---------------------
557 Note that all variables listed here are actually prefixed with *GANETI_*
558 in order to provide a clear namespace. In addition, post-execution
559 scripts receive another set of variables, prefixed with *GANETI_POST_*,
560 representing the status after the opcode executed.
565 This is the list of environment variables supported by all operations:
568 Documents the hooks interface version. In case this doesnt match
569 what the script expects, it should not run. The documents conforms
573 One of *PRE* or *POST* denoting which phase are we in.
582 One of the *OP_* values from the list of operations.
585 One of ``INSTANCE``, ``NODE``, ``CLUSTER``.
588 The path to the Ganeti configuration directory (to read, for
589 example, the *ssconf* files).
592 Specialised variables
593 ~~~~~~~~~~~~~~~~~~~~~
595 This is the list of variables which are specific to one or more
599 IP version of the master IP (4 or 6)
602 The name of the instance which is the target of the operation.
604 INSTANCE_BE_x,y,z,...
605 Instance BE params. There is one variable per BE param. For instance, GANETI_INSTANCE_BE_auto_balance
607 INSTANCE_DISK_TEMPLATE
608 The disk type for the instance.
611 The new disk type for the instance.
614 The number of disks for the instance.
617 The size of disk *n* for the instance.
620 Either *rw* for a read-write disk or *ro* for a read-only one.
622 INSTANCE_HV_x,y,z,...
623 Instance hypervisor options. There is one variable per option. For instance, GANETI_INSTANCE_HV_use_bootloader
626 The instance hypervisor.
629 The number of NICs for the instance.
632 The bridge to which the *n* -th NIC of the instance is attached.
635 The IP (if any) of the *n* -th NIC of the instance.
638 The MAC address of the *n* -th NIC of the instance.
641 The mode of the *n* -th NIC of the instance.
644 The name of the instance OS.
647 The name of the node which is the primary for the instance. Note that
648 for migrations/failovers, you shouldn't rely on this variable since
649 the nodes change during the exectution, but on the
650 OLD_PRIMARY/NEW_PRIMARY values.
653 Space-separated list of secondary nodes for the instance. Note that
654 for migrations/failovers, you shouldn't rely on this variable since
655 the nodes change during the exectution, but on the
656 OLD_SECONDARY/NEW_SECONDARY values.
659 The memory size (in MiBs) of the instance.
662 The number of virtual CPUs for the instance.
665 The run status of the instance.
668 Whether a node is capable of being promoted to master.
671 Whether the node can host instances.
674 Network device of the master IP
680 Netmask of the master IP
683 A space-delimited list of the instance's tags.
686 The target node of this operation (not the node on which the hook
690 The primary IP of the target node (the one over which inter-node
691 communication is done).
694 The secondary IP of the target node (the one over which drbd
695 replication is done). This can be equal to the primary ip, in case
696 the cluster is not dual-homed.
699 This is provided by some operations when the user gave this flag.
702 The user has specified this flag. It is used when failing over
703 instances in case the primary node is down.
706 The mode of the instance create: either *create* for create from
707 scratch or *import* for restoring from an exported image.
709 SRC_NODE, SRC_PATH, SRC_IMAGE
710 In case the instance has been added by import, these variables are
711 defined and point to the source node, source path (the directory
712 containing the image and the config file) and the source disk image
716 The name of the node on which the new mirror component is being
717 added (for replace disk). This can be the name of the current
718 secondary, if the new mirror is on the same secondary. For
719 migrations/failovers, this is the old primary node.
722 The name of the old secondary in the replace-disks command. Note that
723 this can be equal to the new secondary if the secondary node hasn't
724 actually changed. For migrations/failovers, this is the new primary
727 OLD_PRIMARY, NEW_PRIMARY
728 For migrations/failovers, the old and respectively new primary
729 nodes. These two mirror the NEW_SECONDARY/OLD_SECONDARY variables
732 The instance export mode. Either "remote" or "local".
735 The node on which the exported image of the instance was done.
738 This variable tells if the instance has been shutdown or not while
739 doing the export. In the "was shutdown" case, it's likely that the
740 filesystem is consistent, whereas in the "did not shutdown" case,
741 the filesystem would need a check (journal replay or full fsck) in
742 order to guarantee consistency.
745 Whether the instance was removed from the node.
748 Amount of time to wait for the instance to shutdown.
751 Amount of time to wait before aborting the op.
754 Old/new name of the node group.
757 The name of the node group.
760 The new allocation policy for the node group.
763 The list of cluster tags, space separated.
766 The list of tags for node *<name>*, space separated.
771 The startup of an instance will pass this environment to the hook
774 GANETI_CLUSTER=cluster1.example.com
775 GANETI_DATA_DIR=/var/lib/ganeti
777 GANETI_HOOKS_PATH=instance-start
778 GANETI_HOOKS_PHASE=post
779 GANETI_HOOKS_VERSION=2
780 GANETI_INSTANCE_DISK0_MODE=rw
781 GANETI_INSTANCE_DISK0_SIZE=128
782 GANETI_INSTANCE_DISK_COUNT=1
783 GANETI_INSTANCE_DISK_TEMPLATE=drbd
784 GANETI_INSTANCE_MEMORY=128
785 GANETI_INSTANCE_NAME=instance2.example.com
786 GANETI_INSTANCE_NIC0_BRIDGE=xen-br0
787 GANETI_INSTANCE_NIC0_IP=
788 GANETI_INSTANCE_NIC0_MAC=aa:00:00:a5:91:58
789 GANETI_INSTANCE_NIC_COUNT=1
790 GANETI_INSTANCE_OS_TYPE=debootstrap
791 GANETI_INSTANCE_PRIMARY=node3.example.com
792 GANETI_INSTANCE_SECONDARY=node5.example.com
793 GANETI_INSTANCE_STATUS=down
794 GANETI_INSTANCE_VCPUS=1
795 GANETI_MASTER=node1.example.com
796 GANETI_OBJECT_TYPE=INSTANCE
797 GANETI_OP_CODE=OP_INSTANCE_STARTUP
798 GANETI_OP_TARGET=instance2.example.com
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