[CRIU] [PATCH v2] Add docker phaul driver

[Pavel Emelyanov]

Hi, Hui, find my comments inline.

Overall this is much better, but still I'd like to have even less
"if htype.name() == "docker"" stubs over the code. Let's discuss (inline)
what issues you're trying to solve and rework the generic p.haul code
respectively.

> index 11b3dbb..fd2baa3 100644
> --- a/phaul/images.py
> +++ b/phaul/images.py
> @@ -140,6 +140,11 @@ class phaul_images:
>  		logging.info("Sending images to target")
>  
>  		start = time.time()
> +
> +		if htype.get_driver_name() == "docker" :
> +			htype.send_criu_images()
> +			return

In docker driver the send_criu_images() anyway starts the fs_haul_subtree
and rsync-s them. Can you teach the docker driver to always return the
subtree fs hauler to avoid this "if"?

> +
>  		cdir = self.image_dir()
>  
>  		target_host.start_accept_images(phaul_images.IMGDIR)

> diff --git a/phaul/p_haul_iters.py b/phaul/p_haul_iters.py
> index b2c76e3..8f8fb73 100644
> --- a/phaul/p_haul_iters.py
> +++ b/phaul/p_haul_iters.py
> @@ -36,6 +36,13 @@ class phaul_iter_worker:
>  		self.img = images.phaul_images("dmp")
>  
>  		self.htype = p_haul_type.get_src(p_type)
> +
> +		if self.htype.get_driver_name() != "docker" :
> +			# docker will talk to swrk in runc
> +			self.criu_connection = criu_api.criu_conn(self.data_socket)
> +		else:
> +			self.criu_connection = ""
> +

You want to make the "dump" and "pre_dump" stages via Docker API too, am I right?

>  		if not self.htype:
>  			raise Exception("No htype driver found")
>  
> @@ -55,13 +62,16 @@ class phaul_iter_worker:
>  
>  	def set_options(self, opts):
>  		self.target_host.set_options(opts)
> -		self.criu_connection.verbose(opts["verbose"])
> -		self.criu_connection.shell_job(opts["shell_job"])
> +		if self.htype.get_driver_name() != "docker" :
> +			self.criu_connection.verbose(opts["verbose"])
> +			self.criu_connection.shell_job(opts["shell_job"])
> +
>  		self.img.set_options(opts)
>  		self.htype.set_options(opts)
>  		self.fs.set_options(opts)
>  		self.__force = opts["force"]
>  		self.pre_dump = opts["pre_dump"]
> +		self.target_host_ip = opts["to"]
>  
>  	def validate_cpu(self):
>  		logging.info("Checking CPU compatibility")
> @@ -103,13 +113,39 @@ class phaul_iter_worker:
>  
>  		migration_stats.start()
>  
> -		if not self.__force:
> -			self.validate_cpu()
> +		# TODO fix it
> +		if self.htype.get_driver_name() != "docker" :
> +			if not self.__force:
> +				self.validate_cpu()

P.haul does CPU validation itself.

>  
>  		logging.info("Preliminary FS migration")
>  		self.fs.set_work_dir(self.img.work_dir())
>  		self.fs.start_migration()
>  
> +		logging.info("Starting iterations")
> +
> +		# For Docker, we take a different path
> +		if self.htype.get_driver_name() == "docker" :
> +			logging.info("Take a special path for Docker")
> +
> +			self.htype.dump()
> +			logging.info("\tDocker dump succeeded")
> +			logging.info("FS and images sync")
> +			# sync the aufs filesystem again
> +			self.fs.stop_migration()
> +
> +			# send the docker criu image to host
> +			self.htype.send_criu_images(self.target_host_ip)
> +
> +			logging.info("Asking target host to restore")
> +			self.target_host.restore_from_images()
> +
> +			return

Would setting the self.pre_dump to "NO" help to avoid the hand-made
code above?

> +
> +		# TODO: Do not do predump for docker right now. Add page-server
> +		#	to docker C/R API, then we can enable
> +		#	 the pre-dump
> +
>  		logging.info("Checking for Dirty Tracking")
>  		if self.pre_dump == PRE_DUMP_AUTO_DETECT:
>  			# pre-dump auto-detection

> diff --git a/phaul/p_haul_service.py b/phaul/p_haul_service.py
> index 11883a6..f0667fc 100644
> --- a/phaul/p_haul_service.py
> +++ b/phaul/p_haul_service.py
> @@ -45,17 +45,19 @@ class phaul_service:
>  		logging.info("Setting up service side %s", htype_id)
>  		self.img = images.phaul_images("rst")
>  
> -		self.criu_connection = criu_api.criu_conn(self._mem_sk)
>  		self.htype = p_haul_type.get_dst(htype_id)
>  
> -		# Create and start fs receiver if current p.haul module provide it
> -		self.__fs_receiver = self.htype.get_fs_receiver(self._fs_sk)
> -		if self.__fs_receiver:
> -			self.__fs_receiver.start()
> +		if self.htype.get_driver_name() != "docker" :
> +			self.criu_connection = criu_api.criu_conn(self._mem_sk)
> +			# Create and start fs receiver if current p.haul module provide it
> +			self.__fs_receiver = self.htype.get_fs_receiver(self._fs_sk)
> +			if self.__fs_receiver:
> +				self.__fs_receiver.start()

Make docker driver return empty receiver to avoid this "if".

>  
>  	def rpc_set_options(self, opts):
> -		self.criu_connection.verbose(opts["verbose"])
> -		self.criu_connection.shell_job(opts["shell_job"])
> +		if self.htype.get_driver_name() != "docker" :
> +			self.criu_connection.verbose(opts["verbose"])
> +			self.criu_connection.shell_job(opts["shell_job"])
>  		self.img.set_options(opts)
>  		self.htype.set_options(opts)
>  

-- Pavel