The newly added functionality to include the container's root
file-system changes into the checkpoint archive can now be explicitly
disabled. Either during checkpoint or during restore.
If a container changes a lot of files during its runtime it might be
more effective to migrated the root file-system changes in some other
way and to not needlessly increase the size of the checkpoint archive.
If a checkpoint archive does not contain the root file-system changes
information it will automatically be skipped. If the root file-system
changes are part of the checkpoint archive it is also possible to tell
Podman to ignore these changes.
Signed-off-by: Adrian Reber <areber@redhat.com>
the compilation demands of having libpod in main is a burden for the
remote client compilations. to combat this, we should move the use of
libpod structs, vars, constants, and functions into the adapter code
where it will only be compiled by the local client.
this should result in cleaner code organization and smaller binaries. it
should also help if we ever need to compile the remote client on
non-Linux operating systems natively (not cross-compiled).
Signed-off-by: baude <bbaude@redhat.com>
This commit adds an option to the checkpoint command to export a
checkpoint into a tar.gz file as well as importing a checkpoint tar.gz
file during restore. With all checkpoint artifacts in one file it is
possible to easily transfer a checkpoint and thus enabling container
migration in Podman. With the following steps it is possible to migrate
a running container from one system (source) to another (destination).
Source system:
* podman container checkpoint -l -e /tmp/checkpoint.tar.gz
* scp /tmp/checkpoint.tar.gz destination:/tmp
Destination system:
* podman pull 'container-image-as-on-source-system'
* podman container restore -i /tmp/checkpoint.tar.gz
The exported tar.gz file contains the checkpoint image as created by
CRIU and a few additional JSON files describing the state of the
checkpointed container.
Now the container is running on the destination system with the same
state just as during checkpointing. If the container is kept running
on the source system with the checkpoint flag '-R', the result will be
that the same container is running on two different hosts.
Signed-off-by: Adrian Reber <areber@redhat.com>
In cases where the remote client culls options to a command, we need to
be sure that the lookup for that flag does not result in a nil pointer.
To do so, we add a Remote attribute to the podman struct and then cli
helper funcs are now aware they are remote.
Signed-off-by: baude <bbaude@redhat.com>
Conceptually simple: include, where applicable, a brief
description of command-line options for each subcommand.
Signed-off-by: Ed Santiago <santiago@redhat.com>
in the case of the remote-client, it was decided to hide the latest
flag to avoid confusion for end-users on what the "last" container,
volume, or pod are.
Signed-off-by: baude <bbaude@redhat.com>
Signed-off-by: TomSweeneyRedHat <tsweeney@redhat.com>
Adds examples to Cobra help for a second chunk of commands.
Signed-off-by: TomSweeneyRedHat <tsweeney@redhat.com>
Subcommands should not be showing the global flags. This causes the important
information to scroll off the screen.
Also fixed a typo on runCommmand (Too many 'm's)
Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>
We intend to migrate to the cobra cli from urfave/cli because the
project is more well maintained. There are also some technical reasons
as well which extend into our remote client work.
Signed-off-by: baude <bbaude@redhat.com>
We have no consistancy in out option usages and descritions
on whether or not the first letter should be capatalized.
This patch forces them all to be capatilized.
Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>
CRIU can checkpoint and restore processes/containers with established
TCP connections if the correct option is specified. To implement
checkpoint and restore with support for established TCP connections with
Podman this commit adds the necessary options to runc during checkpoint
and also tells conmon during restore to use 'runc restore' with
'--tcp-established'.
For this Podman feature to work a corresponding conmon change is
required.
Example:
$ podman run --tmpfs /tmp --name podman-criu-test -d docker://docker.io/yovfiatbeb/podman-criu-test
$ nc `podman inspect -l | jq -r '.[0].NetworkSettings.IPAddress'` 8080
GET /examples/servlets/servlet/HelloWorldExample
Connection: keep-alive
1
GET /examples/servlets/servlet/HelloWorldExample
Connection: keep-alive
2
$ # Using HTTP keep-alive multiple requests are send to the server in the container
$ # Different terminal:
$ podman container checkpoint -l
criu failed: type NOTIFY errno 0
$ # Looking at the log file would show errors because of established TCP connections
$ podman container checkpoint -l --tcp-established
$ # This works now and after the restore the same connection as above can be used for requests
$ podman container restore -l --tcp-established
The restore would fail without '--tcp-established' as the checkpoint image
contains established TCP connections.
Signed-off-by: Adrian Reber <areber@redhat.com>
CRIU supports to leave processes running after checkpointing:
-R|--leave-running leave tasks in running state after checkpoint
runc also support to leave containers running after checkpointing:
--leave-running leave the process running after checkpointing
With this commit the support to leave a container running after
checkpointing is brought to Podman:
--leave-running, -R leave the container running after writing checkpoint to disk
Now it is possible to checkpoint a container at some point in time
without stopping the container. This can be used to rollback the
container to an early state:
$ podman run --tmpfs /tmp --name podman-criu-test -d docker://docker.io/yovfiatbeb/podman-criu-test
$ curl 10.88.64.253:8080/examples/servlets/servlet/HelloWorldExample
3
$ podman container checkpoint -R -l
$ curl 10.88.64.253:8080/examples/servlets/servlet/HelloWorldExample
4
$ curl 10.88.64.253:8080/examples/servlets/servlet/HelloWorldExample
5
$ podman stop -l
$ podman container restore -l
$ curl 10.88.64.253:8080/examples/servlets/servlet/HelloWorldExample
4
So after checkpointing the container kept running and was stopped after
some time. Restoring this container will restore the state right at the
checkpoint.
Signed-off-by: Adrian Reber <areber@redhat.com>
For upcoming changes to the Checkpoint() functions this commit switches
checkpoint options from a boolean to a struct, so that additional
options can be passed easily to Checkpoint() without changing the
function parameters all the time.
Signed-off-by: Adrian Reber <areber@redhat.com>
runc uses CRIU to support checkpoint and restore of containers. This
brings an initial checkpoint/restore implementation to podman.
None of the additional runc flags are yet supported and container
migration optimization (pre-copy/post-copy) is also left for the future.
The current status is that it is possible to checkpoint and restore a
container. I am testing on RHEL-7.x and as the combination of RHEL-7 and
CRIU has seccomp troubles I have to create the container without
seccomp.
With the following steps I am able to checkpoint and restore a
container:
# podman run --security-opt="seccomp=unconfined" -d registry.fedoraproject.org/f27/httpd
# curl -I 10.22.0.78:8080
HTTP/1.1 403 Forbidden # <-- this is actually a good answer
# podman container checkpoint <container>
# curl -I 10.22.0.78:8080
curl: (7) Failed connect to 10.22.0.78:8080; No route to host
# podman container restore <container>
# curl -I 10.22.0.78:8080
HTTP/1.1 403 Forbidden
I am using CRIU, runc and conmon from git. All required changes for
checkpoint/restore support in podman have been merged in the
corresponding projects.
To have the same IP address in the restored container as before
checkpointing, CNI is told which IP address to use.
If the saved network configuration cannot be found during restore, the
container is restored with a new IP address.
For CRIU to restore established TCP connections the IP address of the
network namespace used for restore needs to be the same. For TCP
connections in the listening state the IP address can change.
During restore only one network interface with one IP address is handled
correctly. Support to restore containers with more advanced network
configuration will be implemented later.
v2:
* comment typo
* print debug messages during cleanup of restore files
* use createContainer() instead of createOCIContainer()
* introduce helper CheckpointPath()
* do not try to restore a container that is paused
* use existing helper functions for cleanup
* restructure code flow for better readability
* do not try to restore if checkpoint/inventory.img is missing
* git add checkpoint.go restore.go
v3:
* move checkpoint/restore under 'podman container'
v4:
* incorporated changes from latest reviews
Signed-off-by: Adrian Reber <areber@redhat.com>
Adrian Reber
baude
Giuseppe Scrivano
Daniel J Walsh
Ed Santiago
TomSweeneyRedHat
Qi Wang