Difference between revisions of "Action scripts"
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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: | |
| − | ; | + | ;<code>pre-dump</code> |
| − | : | + | : called before the beginning of dump |
| − | ;network-unlock | + | ;<code>post-dump</code> |
| − | : requested to unlock an [[ | + | : called when CRIU finished dumping tasks and before unfreezing them |
| + | |||
| + | ;<code>pre-restore</code> | ||
| + | : called before the beginning of restore | ||
| + | |||
| + | ;<code>post-restore</code> | ||
| + | : 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> | ||
| + | : called when the root task is alive and new set of namespaces is created to set them up | ||
| + | |||
| + | ;<code>post-setup-namespaces</code> | ||
| + | : called after namespaces are configured | ||
| + | |||
| + | ;<code>pre-resume</code> | ||
| + | : called at the moment when processes and resources are already restored but not yet in running state | ||
| + | |||
| + | ;<code>post-resume</code> | ||
| + | : called at the very end, when everything is restored and processes were resumed | ||
| + | |||
| + | ;<code>orphan-pts-master</code> | ||
| + | : 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 == | ||
| + | |||
| + | 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. | ||
| + | |||
| + | == RPC == | ||
| + | |||
| + | 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>. | ||
| + | |||
| + | == Library == | ||
| + | |||
| + | When using a library, one can set up a callback using the <code>criu_set_notify_cb</code> routine. | ||
| + | |||
| + | [[Category:HOWTO]] | ||
| + | [[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-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.