[CRIU] [PATCH v5] Add docker phaul driver
Hui Kang
hkang.sunysb at gmail.com
Mon Oct 26 12:44:07 PDT 2015
On Mon, Oct 26, 2015 at 3:41 PM, Hui Kang <hkang.sunysb at gmail.com> wrote:
> 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?
>>
>>>>
>>>>> 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.
>>
>> I would leave the cases then pre_dump is set explicitly alone, so that we
>> could _force_ pre_dump-s with command-line.
>>
>>>>
>>>>> 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.
>>
>>> 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.
>
> This idea may be implemented without adding dump_need_ps() for each htype.
> Instead, can we add a parameter rpc_start_iter to denote if
> page_server should be started or not? It looks like
Continued from last email.
while self.pre_dump:
self.target_host.start_iter(true)
....
logging.info("Final dump and restore")
self.target_host.start_iter(false)
def rpc_start_iter(self, need_ps)
if need_ps:
start_page_server
>
>
>
>
>
>>
>> -- Pavel
>>
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