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This adds support to checkpoint containers out of pods and restore container into pods. It is only possible to restore a container into a pod if it has been checkpointed out of pod. It is also not possible to restore a non pod container into a pod. The main reason this does not work is the PID namespace. If a non pod container is being restored in a pod with a shared PID namespace, at least one process in the restored container uses PID 1 which is already in use by the infrastructure container. If someone tries to restore container from a pod with a shared PID namespace without a shared PID namespace it will also fail because the resulting PID namespace will not have a PID 1. Signed-off-by: Adrian Reber <areber@redhat.com>
6.1 KiB
% podman-container-restore(1)
NAME
podman-container-restore - Restores one or more containers from a checkpoint
SYNOPSIS
podman container restore [options] container [container ...]
DESCRIPTION
podman container restore restores a container from a checkpoint. The container IDs or names are used as input.
OPTIONS
--all, -a
Restore all checkpointed containers.
The default is false.
IMPORTANT: This OPTION does not need a container name or ID as input argument.
--keep, -k
Keep all temporary log and statistics files created by CRIU during
checkpointing as well as restoring. These files are not deleted if restoring
fails for further debugging. If restoring succeeds these files are
theoretically not needed, but if these files are needed Podman can keep the
files for further analysis. This includes the checkpoint directory with all
files created during checkpointing. The size required by the checkpoint
directory is roughly the same as the amount of memory required by the
processes in the checkpointed container.
Without the --keep, -k option the checkpoint will be consumed and cannot be used again.
The default is false.
--latest, -l
Instead of providing the container ID or name, use the last created container. If other tools than Podman are used to run containers such as CRI-O, the last started container could be from either tool.
The default is false.
IMPORTANT: This OPTION is not available with the remote Podman client. This OPTION does not need a container name or ID as input argument.
--ignore-rootfs
If a container is restored from a checkpoint tar.gz file it is possible that it also contains all root file-system changes. With --ignore-rootfs it is possible to explicitly disable applying these root file-system changes to the restored container.
The default is false.
IMPORTANT: This OPTION is only available in combination with --import, -i.
--ignore-static-ip
If the container was started with --ip the restored container also tries to use that IP address and restore fails if that IP address is already in use. This can happen, if a container is restored multiple times from an exported checkpoint with --name, -n.
Using --ignore-static-ip tells Podman to ignore the IP address if it was configured with --ip during container creation.
The default is false.
--ignore-static-mac
If the container was started with --mac-address the restored container also tries to use that MAC address and restore fails if that MAC address is already in use. This can happen, if a container is restored multiple times from an exported checkpoint with --name, -n.
Using --ignore-static-mac tells Podman to ignore the MAC address if it was configured with --mac-address during container creation.
The default is false.
--ignore-volumes
This option must be used in combination with the --import, -i option.
When restoring containers from a checkpoint tar.gz file with this option,
the content of associated volumes will not be restored.
The default is false.
--import, -i=file
Import a checkpoint tar.gz file, which was exported by Podman. This can be used
to import a checkpointed container from another host.
IMPORTANT: This OPTION does not need a container name or ID as input argument.
--import-previous=file
Import a pre-checkpoint tar.gz file which was exported by Podman. This option
must be used with -i or --import. It only works on runc 1.0-rc3 or higher.
--name, -n=name
If a container is restored from a checkpoint tar.gz file it is possible to rename it with --name, -n. This way it is possible to restore a container from a checkpoint multiple times with different names.
If the --name, -n option is used, Podman will not attempt to assign the same IP
address to the container it was using before checkpointing as each IP address can only
be used once and the restored container will have another IP address. This also means
that --name, -n cannot be used in combination with --tcp-established.
IMPORTANT: This OPTION is only available in combination with --import, -i.
--pod=name
Restore a container into the pod name. The destination pod for this restore has to have the same namespaces shared as the pod this container was checkpointed from (see podman pod create --share). IMPORTANT: This OPTION is only available in combination with --import, -i.
This option requires at least CRIU 3.16.
--publish, -p=port
Replaces the ports that the container publishes, as configured during the initial container start, with a new set of port forwarding rules.
For more details please see podman run --publish.
--tcp-established
Restore a container with established TCP connections. If the checkpoint image
contains established TCP connections, this option is required during restore.
If the checkpoint image does not contain established TCP connections this
option is ignored. Defaults to not restoring containers with established TCP
connections.
The default is false.
EXAMPLE
Restores the container "mywebserver".
# podman container restore mywebserver
Import a checkpoint file and a pre-checkpoint file.
# podman container restore --import-previous pre-checkpoint.tar.gz --import checkpoint.tar.gz
Remove the container "mywebserver". Make a checkpoint of the container and export it. Restore the container with other port ranges from the exported file.
$ podman run --rm -p 2345:80 -d webserver
# podman container checkpoint -l --export=dump.tar
# podman container restore -p 5432:8080 --import=dump.tar
SEE ALSO
podman(1), podman-container-checkpoint(1), podman-run(1), podman-pod-create(1)
HISTORY
September 2018, Originally compiled by Adrian Reber areber@redhat.com