[CRIU] [PATCH v5] Add docker phaul driver
Hui Kang
hkang.sunysb at gmail.com
Mon Oct 26 11:53:03 PDT 2015
On Mon, Oct 26, 2015 at 2:26 PM, Pavel Emelyanov <xemul at parallels.com> wrote:
> On 10/26/2015 08:59 PM, Hui Kang wrote:
>> Hi, Pavel
>> Thanks for your comment. Please see my reply inline.
>>
>> On Mon, Oct 26, 2015 at 5:06 AM, Pavel Emelyanov <xemul at parallels.com> wrote:
>>> Please, find my comment inline.
>>>
>>>> diff --git a/p.haul b/p.haul
>>>> index 11460b4..478e1c7 100755
>>>> --- a/p.haul
>>>> +++ b/p.haul
>>>> @@ -25,7 +25,7 @@ import phaul.htype
>>>>
>>>> parser = argparse.ArgumentParser("Process HAULer")
>>>> parser.add_argument("type", choices=phaul.htype.get_haul_names(),
>>>> - help="Type of hat to haul, e.g. vz or lxc")
>>>> + help="Type of hat to haul, e.g. vz, lxc, or docker")
>>>> parser.add_argument("id", help="ID of what to haul")
>>>> parser.add_argument("--to", help="IP where to haul")
>>>> parser.add_argument("--fdrpc", help="File descriptor of rpc socket", type=int, required=True)
>>>> diff --git a/phaul/fs_haul_subtree.py b/phaul/fs_haul_subtree.py
>>>> index a9bd559..e20ad1b 100644
>>>> --- a/phaul/fs_haul_subtree.py
>>>> +++ b/phaul/fs_haul_subtree.py
>>>> @@ -11,29 +11,38 @@ import logging
>>>> rsync_log_file = "rsync.log"
>>>>
>>>> class p_haul_fs:
>>>> - def __init__(self, subtree_path):
>>>> - logging.info("Initialized subtree FS hauler (%s)", subtree_path)
>>>> - self.__root = subtree_path
>>>> + def __init__(self, subtree_paths):
>>>> + self.__roots = []
>>>> + for path in subtree_paths:
>>>> + logging.info("Initialized subtree FS hauler (%s)", path)
>>>> + self.__roots.append(path)
>>>> +
>>>> self.__thost = None
>>>>
>>>> def set_options(self, opts):
>>>> self.__thost = opts["to"]
>>>>
>>>> + def set_target_host(self, thost):
>>>> + self.__thost = thost
>>>> +
>>>> def set_work_dir(self, wdir):
>>>> self.__wdir = wdir
>>>>
>>>> def __run_rsync(self):
>>>> logf = open(os.path.join(self.__wdir, rsync_log_file), "w+")
>>>> - dst = "%s:%s" % (self.__thost, os.path.dirname(self.__root))
>>>>
>>>> - # First rsync might be very long. Wait for it not
>>>> - # to produce big pause between the 1st pre-dump and
>>>> - # .stop_migration
>>>> + for dir_name in self.__roots:
>>>> +
>>>> + dst = "%s:%s" % (self.__thost, os.path.dirname(dir_name))
>>>> +
>>>> + # First rsync might be very long. Wait for it not
>>>> + # to produce big pause between the 1st pre-dump and
>>>> + # .stop_migration
>>>>
>>>> - ret = sp.call(["rsync", "-a", self.__root, dst],
>>>> + ret = sp.call(["rsync", "-a", dir_name, dst],
>>>> stdout = logf, stderr = logf)
>>>> - if ret != 0:
>>>> - raise Exception("Rsync failed")
>>>> + if ret != 0:
>>>> + raise Exception("Rsync failed")
>>>>
>>>> def start_migration(self):
>>>> logging.info("Starting FS migration")
>>>> diff --git a/phaul/htype.py b/phaul/htype.py
>>>> index f3a4774..bee49b4 100644
>>>> --- a/phaul/htype.py
>>>> +++ b/phaul/htype.py
>>>> @@ -11,6 +11,7 @@ __haul_modules = {
>>>> "vz": "p_haul_vz",
>>>> "pid": "p_haul_pid",
>>>> "lxc": "p_haul_lxc",
>>>> + "docker": "p_haul_docker",
>>>> }
>>>>
>>>> def __get(id):
>>>> diff --git a/phaul/images.py b/phaul/images.py
>>>> index 57dca59..e48f96f 100644
>>>> --- a/phaul/images.py
>>>> +++ b/phaul/images.py
>>>> @@ -145,7 +145,8 @@ class phaul_images:
>>>> tf = img_tar(sk, cdir)
>>>>
>>>> logging.info("\tPack")
>>>> - for img in filter(lambda x: x.endswith(".img"), os.listdir(cdir)):
>>>> + # .json file is needed for docker, i.e., descriptor.json
>>>> + for img in filter(lambda x: x.endswith(('.img', '.json')) , os.listdir(cdir)):
>>>
>>> Why do we include .json files from images dir? Where do the come from?
>>
>> This descriptors.json is generated by "docker checkpoint". I copied
>> its content here
>>
>> cat /var/run/docker/execdriver/native/4fe6ae42044ecb216788a2dc8cae900f9bd3ca93b7e84a1cee56acfe34c46e32/criu.image/descriptors.json
>> ["/dev/null","pipe:[1095038]","pipe:[1095039]"]
>>
>> "docker restore" will fail without this descriptors.json. Since this
>> file exists with all other criu images, we can use sync_image to send
>> the file.
>
> OK. Would you feed one into the transfer blob via the put_meta_images() callback?
>
No, I do not think put_meta_images() does any transfer task. If we add
some transfer code in put_meta_images only for the descriptor.json;
kind of overkilling. In addition, since this descriptor.json stays
with other criu.images, sync_imgs_to_target() maybe a better choice.
What do you think?
>>>
>>>> tf.add(img)
>>>>
>>>> logging.info("\tAdd htype images")
>>>> diff --git a/phaul/iters.py b/phaul/iters.py
>>>> index 9be4e97..00b2a02 100644
>>>> --- a/phaul/iters.py
>>>> +++ b/phaul/iters.py
>>>> @@ -113,7 +113,7 @@ class phaul_iter_worker:
>>>> if self.pre_dump == PRE_DUMP_AUTO_DETECT:
>>>> # pre-dump auto-detection
>>>> try:
>>>> - self.pre_dump = self.pre_dump_check()
>>>> + self.pre_dump = (self.pre_dump_check() and self.htype.can_pre_dump())
>>>> logging.info("\t`- Auto %s" % (self.pre_dump and 'enabled' or 'disabled'))
>>>> except:
>>>> # The available criu seems to not
>>>> @@ -121,6 +121,11 @@ class phaul_iter_worker:
>>>> self.pre_dump = PRE_DUMP_DISABLE
>>>> logging.info("\t`- Auto detection not possible "
>>>> "- Disabled")
>>>> + elif self.pre_dump == PRE_DUMP_DISABLE:
>>>> + logging.info("\t`- Command-line disabled")
>>>> + elif self.htype.can_pre_dump() == False:
>>>> + self.pre_dump = False
>>>> + logging.info("\t`- Type does not support pre-dump")
>>>
>>> Why is this elif elif part required?
>>
>> This elif means if pre_dump is set true in command line, we need to
>> further check if the phaul type supports pre_dump.
>
> But you don't -- the call for self.htype.can_pre_dump() is only done above,
> when pre_dump is set to AUTO_DETECT.
This "elif self.htype.can_pre_dump() == False:" calls can_pre_dump()
if pre_dump is not set to AUTO_DETECT.
>
> I would leave the cases then pre_dump is set explicitly alone, so that we
> could _force_ pre_dump-s with command-line.
If we remove this "elif self.htype.can_pre_dump() == False:", then the
chances are pre_dump is set explicity true in the command line while
the type may not support pre_dump(). So i think this check is
necessary.
>
>>>
>>>> else:
>>>> logging.info("\t`- Command-line %s" % (self.pre_dump and 'enabled' or 'disabled'))
>>>>
>>>> diff --git a/phaul/p_haul_docker.py b/phaul/p_haul_docker.py
>>>> new file mode 100644
>>>> index 0000000..d2bb1e3
>>>> --- /dev/null
>>>> +++ b/phaul/p_haul_docker.py
>>>> @@ -0,0 +1,158 @@
>>>> +#
>>>> +# Docker container hauler
>>>> +#
>>>> +
>>>> +import os
>>>> +import logging
>>>> +import time
>>>> +import fs_haul_subtree
>>>> +import pycriu.rpc
>>>> +import json
>>>> +from pprint import pprint
>>>> +import subprocess as sp
>>>> +from subprocess import PIPE
>>>> +
>>>> +# TODO use docker-py
>>>> +# import docker
>>>> +
>>>> +# Some constants for docker
>>>> +name = "docker"
>>>> +docker_exec = "/usr/bin/docker-1.9.0-dev"
>>>> +docker_dir = "/var/lib/docker/"
>>>> +docker_run_meta_dir = "/var/run/docker/execdriver/native"
>>>> +
>>>> +class p_haul_type:
>>>> + def __init__(self, ctid):
>>>> +
>>>> + # TODO ctid must > 3 digit; with docker-py, we can also resolve
>>>> + # container name
>>>> + if len(ctid) < 3:
>>>> + raise Exception("Docker container ID must be > 3 digits")
>>>> +
>>>> + self._ctid = ctid
>>>> + self._ct_rootfs = ""
>>>> +
>>>> + def get_driver_name(self):
>>>> + return name
>>>> +
>>>> + def init_src(self):
>>>> + self.full_ctid = self.get_full_ctid()
>>>> + self.__load_ct_config(docker_dir)
>>>> +
>>>> + def init_dst(self):
>>>> + pass
>>>> +
>>>> + def adjust_criu_req(self, req):
>>>> + """Add module-specific options to criu request"""
>>>> + pass
>>>> +
>>>> + def root_task_pid(self):
>>>> + # Do we need this for Docker?
>>>> + return self.full_ctid
>>>> +
>>>> + def __load_ct_config(self, path):
>>>> +
>>>> + # Each docker container has 3 directories that need to be
>>>> + # migrated: (1) root filesystem, (2) container configuration,
>>>> + # (3) runtime meta state
>>>> + self._ct_rootfs = os.path.join(docker_dir, "aufs/mnt", self.full_ctid)
>>>> + self._ct_config_dir = os.path.join(docker_dir, "containers", self.full_ctid)
>>>> + self._ct_run_meta_dir = os.path.join(docker_run_meta_dir, self.full_ctid)
>>>> + logging.info("Container rootfs: %s", self._ct_rootfs)
>>>> + logging.info("Container config: %s", self._ct_config_dir)
>>>> + logging.info("Container meta: %s", self._ct_run_meta_dir)
>>>> +
>>>> + def set_options(self, opts):
>>>> + pass
>>>> +
>>>> + # Remove any specific FS setup
>>>> + def umount(self):
>>>> + pass
>>>> +
>>>> + def get_fs(self, fs_sk=None):
>>>> + # use rsync for rootfs and configuration directories
>>>> + return fs_haul_subtree.p_haul_fs([self._ct_rootfs, self._ct_config_dir])
>>>> +
>>>> + def get_fs_receiver(self, fs_sk=None):
>>>> + return None
>>>> +
>>>> + def get_full_ctid(self):
>>>> + dir_name_list = os.listdir(os.path.join(docker_dir, "containers"))
>>>> +
>>>> + full_id = ""
>>>> + for name in dir_name_list:
>>>> + name = name.rsplit("/")
>>>> + if (name[0].find(self._ctid) == 0):
>>>> + full_id = name[0]
>>>> + break
>>>> +
>>>> + if full_id != "":
>>>> + return full_id
>>>> + else:
>>>> + raise Exception("Can not find container fs")
>>>> +
>>>> + def final_dump(self, pid, img, ccon, fs):
>>>> + logging.info("Dump docker container %s", pid)
>>>> +
>>>> + # TODO: docker API does not have checkpoint right now
>>>> + # cli.checkpoint() so we have to use the command line
>>>> + # cli = docker.Client(base_url='unix://var/run/docker.sock')
>>>> + # output = cli.info()
>>>> + # call docker API
>>>> +
>>>> + logf = open("/tmp/docker_checkpoint.log", "w+")
>>>> + image_path_opt = "--image-dir=" + img.image_dir()
>>>> + ret = sp.call([docker_exec, "checkpoint", image_path_opt, self._ctid],
>>>> + stdout = logf, stderr = logf)
>>>> + if ret != 0:
>>>> + raise Exception("docker checkpoint failed")
>>>> + #
>>>> + # Meta-images for docker -- /var/run/docker
>>>> + #
>>>> + def get_meta_images(self, path):
>>>> + # Send the meta state file with criu images
>>>> + return [(os.path.join(self._ct_run_meta_dir, "state.json"), "state.json")]
>>>> +
>>>> + def put_meta_images(self, dir):
>>>> + # Create docker runtime meta dir on dst side
>>>> + with open(os.path.join(dir, "state.json")) as data_file:
>>>> + data = json.load(data_file)
>>>> + self.full_ctid=data["id"]
>>>> +
>>>> + self.__load_ct_config(docker_dir)
>>>> + os.makedirs(self._ct_run_meta_dir)
>>>> + pd = sp.Popen(["cp", os.path.join(dir, "state.json"), self._ct_run_meta_dir], stdout = PIPE)
>>>> + status = pd.wait()
>>>> +
>>>> + def kill_last_docker_daemon(self):
>>>> + p = sp.Popen(['pgrep', '-l' , docker_exec], stdout=sp.PIPE)
>>>> + out, err = p.communicate()
>>>> +
>>>> + for line in out.splitlines():
>>>> + line = bytes.decode(line)
>>>> + pid = int(line.split(None, 1)[0])
>>>> + os.kill(pid, signal.SIGKILL)
>>>> +
>>>> + def final_restore(self, img, criu):
>>>> + logf = open("/tmp/docker_restore.log", "w+")
>>>> +
>>>> + # Kill any previous docker daemon in order to reload the
>>>> + # status of the migrated container
>>>> + self.kill_last_docker_daemon()
>>>> +
>>>> + # start docker daemon in background
>>>> + daemon = sp.Popen([docker_exec, "daemon", "-s", "aufs"],
>>>> + stdout = logf, stderr = logf)
>>>> + # daemon.wait() TODO: docker daemon not return
>>>> + time.sleep(2)
>>>> +
>>>> + image_path_opt = "--image-dir=" + img.image_dir()
>>>> + ret = sp.call([docker_exec, "restore", image_path_opt, self._ctid],
>>>> + stdout = logf, stderr = logf)
>>>> + if ret != 0:
>>>> + raise Exception("docker restore failed")
>>>> +
>>>> + def can_pre_dump(self):
>>>> + # XXX: Do not do predump for docker right now. Add page-server
>>>> + # to docker C/R API, then we can enable the pre-dump
>>>> + return False
>>>> diff --git a/phaul/p_haul_pid.py b/phaul/p_haul_pid.py
>>>> index e354dff..43af654 100644
>>>> --- a/phaul/p_haul_pid.py
>>>> +++ b/phaul/p_haul_pid.py
>>>> @@ -94,3 +94,6 @@ class p_haul_type:
>>>> # Get list of veth pairs if any
>>>> def veths(self):
>>>> return []
>>>> +
>>>> + def can_pre_dump(self):
>>>> + return True
>>>> diff --git a/phaul/p_haul_vz.py b/phaul/p_haul_vz.py
>>>> index 903006d..e346bdf 100644
>>>> --- a/phaul/p_haul_vz.py
>>>> +++ b/phaul/p_haul_vz.py
>>>> @@ -244,6 +244,9 @@ class p_haul_type:
>>>> return True
>>>>
>>>>
>>>> + def can_pre_dump(self):
>>>> + return True
>>>> +
>>>> def parse_vz_config(body):
>>>> """Parse shell-like virtuozzo config file"""
>>>>
>>>> diff --git a/phaul/service.py b/phaul/service.py
>>>> index a03b43e..507d171 100644
>>>> --- a/phaul/service.py
>>>> +++ b/phaul/service.py
>>>> @@ -72,7 +72,8 @@ class phaul_service:
>>>> def rpc_start_iter(self):
>>>> self.dump_iter_index += 1
>>>> self.img.new_image_dir()
>>>> - self.start_page_server()
>>>> + if self.htype.get_driver_name() != "docker" :
>>>> + self.start_page_server()
>>>
>>> Explicit docker check again. What bad happens if you let the page server
>>> spawn?
>>
>> Here is the error message after remoing the check for docker:
>>
>> 17:50:24.551: Page server started at 3833
>> 17:50:32.329: Started images server
>> 17:50:32.333: Exception in untar_thread
>> Traceback (most recent call last):
>> File "/root/development/p.haul/phaul/images.py", line 42, in run
>> tf = tarfile.open(mode="r|", fileobj=util.fileobj_wrap(self.__sk))
>> File "/usr/lib/python2.7/tarfile.py", line 1690, in open
>> **kwargs)
>> File "/usr/lib/python2.7/tarfile.py", line 1574, in __init__
>> self.firstmember = self.next()
>> File "/usr/lib/python2.7/tarfile.py", line 2335, in next
>> raise ReadError(str(e))
>> ReadError: bad checksum
>
> O_o But this has (should have) nothing to do with page-server, it's
> just some tarfile internal stuff.
>
You are right. However, whenever I disable page_server, the error
message goes away. Eachtime I enable it, error comes back. So I doubt
page_server() may be relevant to the error.
>> 17:50:32.348: Waiting for images to unpack
>> 17:50:32.349: Restoring from images
>>
>> I doubt that is is because there is not pre_dump for docker, so the
>> page_server does not receive any criu image. Is this correct?
>
> AFAIU yes, you do final dump on disk, so page server is reqlly unneeded
> here. Please, see my next commend about what to do with it.
>
>>>
>>> BTW, a question to Nikita -- I don't see in p_haul_vz.py that we do final
>>> dump go via page-server. Do we?
>>
>>>From my understanding, no final dump may go via page-server. The criu
>> images are sent using tar/untar via the mem_sk.
>
> OK, so what we have here is -- final dump for everyone is done w/o the
> page server. That's a pity we should fix, but for now let's make yet
> another (temporary) htype method 'dump_need_ps()' denoting that final
> dump does or does not go via page-server and start or not this guy
> respectively. OK? Some time soon this will be removed, but for now
> let's make it w/o explicit "name == docker" checks.
I like this idea to remove the name check for docker.
- Hui
>
> -- Pavel
>
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