Difference between revisions of "Action scripts"

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(Created page with "Currently the following hooks are in use ;network-lock : Requested to lock an LXC container network ;network-unlock : Requested to unlock an LXC container network")
 
m (→‎Library: Replace 'criu_set_notify' with 'criu_set_notify_cb')
 
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Currently the following hooks are in use
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With the <code>--action-script</code> command line option, CRIU can call your action scripts (also known as hooks) at various stages of dumping/restoring. The following hooks are available:
  
;network-lock
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;<code>pre-dump</code>
: Requested to lock an [[LXC]] container network
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: called before the beginning of dump
  
;network-unlock
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;<code>post-dump</code>
: Requested to unlock an [[LXC]] container network
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: called when CRIU finished dumping tasks and before unfreezing them
 +
 
 +
;<code>pre-restore</code>
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: called before the beginning of restore
 +
 
 +
;<code>post-restore</code>
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: called when CRIU has finished restoring tasks and before unlocking the network
 +
 
 +
;<code>network-lock</code>
 +
: request to lock a container network (used by [[Docker]] and [[LXC]])
 +
 
 +
;<code>network-unlock</code>
 +
: requested to unlock a container network (used by Docker and LXC)
 +
 
 +
;<code>setup-namespaces</code>
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: called when the root task is alive and new set of namespaces is created to set them up
 +
 
 +
;<code>post-setup-namespaces</code>
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: called after namespaces are configured
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;<code>pre-resume</code>
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: called at the moment when processes and resources are already restored but not yet in running state
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 +
;<code>post-resume</code>
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: called at the very end, when everything is restored and processes were resumed
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;<code>orphan-pts-master</code>
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: called after master pty is opened and unlocked (used by Docker). Used only in RPC mode, and the notification message contains a file descriptor for the master pty.
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== CLI ==
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These hooks are added with the <code>--action-script ''shell-code-to-execute''</code> option. When called, the <code>CRTOOLS_SCRIPT_ACTION</code> environment is set to a value determining which type of action is performed.
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== RPC ==
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In case of RPC, action scripts are implemented as notifications. Once CRIU service wants to execute a script, it sends an RPC message to the caller and waits for it to respond with <code>criu_req</code> message having <code>notify_success = true</code>.
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== Library ==
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When using a library, one can set up a callback using the <code>criu_set_notify_cb</code> routine.
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[[Category:HOWTO]]
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[[Category:API]]

Latest revision as of 22:48, 28 February 2020

With the --action-script command line option, CRIU can call your action scripts (also known as hooks) at various stages of dumping/restoring. The following hooks are available:

pre-dump
called before the beginning of dump
post-dump
called when CRIU finished dumping tasks and before unfreezing them
pre-restore
called before the beginning of restore
post-restore
called when CRIU has finished restoring tasks and before unlocking the network
network-lock
request to lock a container network (used by Docker and LXC)
network-unlock
requested to unlock a container network (used by Docker and LXC)
setup-namespaces
called when the root task is alive and new set of namespaces is created to set them up
post-setup-namespaces
called after namespaces are configured
pre-resume
called at the moment when processes and resources are already restored but not yet in running state
post-resume
called at the very end, when everything is restored and processes were resumed
orphan-pts-master
called after master pty is opened and unlocked (used by Docker). Used only in RPC mode, and the notification message contains a file descriptor for the master pty.

CLI[edit]

These hooks are added with the --action-script shell-code-to-execute option. When called, the CRTOOLS_SCRIPT_ACTION environment is set to a value determining which type of action is performed.

RPC[edit]

In case of RPC, action scripts are implemented as notifications. Once CRIU service wants to execute a script, it sends an RPC message to the caller and waits for it to respond with criu_req message having notify_success = true.

Library[edit]

When using a library, one can set up a callback using the criu_set_notify_cb routine.