[CRIU] [PATCH 2/4] p.haul: merge commits from https://github.com/ThomasJClark/criu-gui-demo

[Pavel Emelyanov]

> +class Dump(_DRBase):
> +    """
> +        This class dumps a process using CRIU when it receives an HTTP POST.
> +    """
> +
> +    def POST(self):
> +        """
> +            Attempt to dump a process, where the PID is given in the URL
> +            parameter "pid".
> +        """
> +
> +        web.header("Content-Type", "application/json")
> +        web.header("Access-Control-Allow-Origin", "*")
> +        pid = web.input().get("pid")
> +
> +        if not pid or not pid.isnumeric():
> +            result = {"succeeded": False, "why": "No PID specified"}
> +            raise web.badrequest(json.dumps(result, separators=",:"))
> +
> +        self.connect()
> +
> +        self.tempdir = tempfile.mkdtemp()
> +
> +        # Send a request to dump the specified process
> +        req = criu.criu_req()
> +        req.type = criu.DUMP
> +        req.opts.pid = int(pid)
> +        req.opts.shell_job = False
> +        req.opts.manage_cgroups = True
> +        req.opts.images_dir_fd = os.open(self.tempdir, os.O_DIRECTORY)
> +
> +        resp = self.transaction(req)
> +
> +        # Create a tar of all of the images and send it base64-encoded back to
> +        # the client.  This is okay for a small demo, but obviously a real
> +        # application would probably not be this wasteful with resources.
> +        temptar = tempfile.mktemp()
> +
> +        with tarfile.open(temptar, "w:gz") as tar:
> +            for f in os.listdir(self.tempdir):
> +                tar.add(self.tempdir + "/" + f)
> +            tar.close()
> +
> +        with open(temptar, "r") as tar:
> +            data = base64.b64encode(tar.read())
> +
> +        return json.dumps({"succeeded": True, "data": data,
> +                          "dir": self.tempdir}, separators=",:")
> +
> +
> +class Restore(_DRBase):
> +    """
> +        This class restores a process using CRIU when it receives an HTTP POST.
> +    """
> +
> +    def POST(self):
> +        """
> +            Attempt to restore a process, where the directory where the
> +            proccess images are is given in the URL parameter "dir".
> +        """
> +
> +        web.header("Content-Type", "application/json")
> +        web.header("Access-Control-Allow-Origin", "*")
> +
> +        if "data" not in web.input():
> +            result = {"succeeded": False, "why": "No image data provided"}
> +            raise web.badrequest(json.dumps(result, separators=",:"))
> +
> +        if "dir" not in web.input():
> +            result = {"succeeded": False, "why": "No image directory provided"}
> +            raise web.badrequest(json.dumps(result, separators=",:"))
> +
> +        # Extract the images from the base64-encoding tarball.
> +        temptar = tempfile.mktemp()
> +        self.tempdir = web.input()["dir"]
> +
> +        print self.tempdir
> +
> +        with open(temptar, "w") as tar:
> +            tar.write(base64.b64decode(web.input()["data"]))
> +
> +        with tarfile.open(temptar, "r:gz") as tar:
> +            tar.list()
> +            tar.extractall("/")
> +
> +        try:
> +            dir_fd = os.open(self.tempdir, os.O_DIRECTORY)
> +        except OSError as e:
> +            result = {"succeeded": False, "why": e.strerror}
> +            raise web.badrequest(json.dumps(result, separators=",:"))
> +
> +        self.connect()
> +
> +        # Send a request to restore the specified process
> +        req = criu.criu_req()
> +        req.type = criu.RESTORE
> +        req.opts.shell_job = False
> +        req.opts.manage_cgroups = True
> +        req.opts.images_dir_fd = dir_fd
> +
> +        resp = self.transaction(req)
> +        return json.dumps({"succeeded": True}, separators=",:")

BTW, that's not "fair" live migration -- it's an emulation of it using two calls -- dump
and restore. Why not call p_haul classes for "fair" live migration?

-- Pavel