7751: Move code from arv-mount executable to module.
authorTom Clegg <tom@curoverse.com>
Thu, 19 Nov 2015 22:37:25 +0000 (17:37 -0500)
committerTom Clegg <tom@curoverse.com>
Wed, 25 Nov 2015 15:44:58 +0000 (10:44 -0500)
services/fuse/arvados_fuse/command.py [new file with mode: 0644]
services/fuse/arvados_fuse/crunchstat.py [new file with mode: 0644]
services/fuse/bin/arv-mount

diff --git a/services/fuse/arvados_fuse/command.py b/services/fuse/arvados_fuse/command.py
new file mode 100644 (file)
index 0000000..e9d8bb5
--- /dev/null
@@ -0,0 +1,331 @@
+import argparse
+import arvados
+import daemon
+import llfuse
+import logging
+import os
+import signal
+import subprocess
+import sys
+import time
+
+import arvados.commands._util as arv_cmd
+from arvados_fuse import crunchstat
+from arvados_fuse import *
+
+class ArgumentParser(argparse.ArgumentParser):
+    def __init__(self):
+        super(ArgumentParser, self).__init__(
+            parents=[arv_cmd.retry_opt],
+            description='''Mount Keep data under the local filesystem.  Default mode is --home''',
+            epilog="""
+    Note: When using the --exec feature, you must either specify the
+    mountpoint before --exec, or mark the end of your --exec arguments
+    with "--".
+            """)
+        self.add_argument('mountpoint', type=str, help="""Mount point.""")
+        self.add_argument('--allow-other', action='store_true',
+                            help="""Let other users read the mount""")
+
+        mode = self.add_mutually_exclusive_group()
+
+        mode.add_argument('--all', action='store_const', const='all', dest='mode',
+                                help="""Mount a subdirectory for each mode: home, shared, by_tag, by_id (default if no --mount-* arguments are given).""")
+        mode.add_argument('--custom', action='store_const', const=None, dest='mode',
+                                help="""Mount a top level meta-directory with subdirectories as specified by additional --mount-* arguments (default if any --mount-* arguments are given).""")
+        mode.add_argument('--home', action='store_const', const='home', dest='mode',
+                                help="""Mount only the user's home project.""")
+        mode.add_argument('--shared', action='store_const', const='shared', dest='mode',
+                                help="""Mount only list of projects shared with the user.""")
+        mode.add_argument('--by-tag', action='store_const', const='by_tag', dest='mode',
+                                help="""Mount subdirectories listed by tag.""")
+        mode.add_argument('--by-id', action='store_const', const='by_id', dest='mode',
+                                help="""Mount subdirectories listed by portable data hash or uuid.""")
+        mode.add_argument('--by-pdh', action='store_const', const='by_pdh', dest='mode',
+                                help="""Mount subdirectories listed by portable data hash.""")
+        mode.add_argument('--project', type=str, metavar='UUID',
+                                help="""Mount the specified project.""")
+        mode.add_argument('--collection', type=str, metavar='UUID_or_PDH',
+                                help="""Mount only the specified collection.""")
+
+        mounts = self.add_argument_group('Custom mount options')
+        mounts.add_argument('--mount-by-pdh',
+                            type=str, metavar='PATH', action='append', default=[],
+                            help="Mount each readable collection at mountpoint/PATH/P where P is the collection's portable data hash.")
+        mounts.add_argument('--mount-by-id',
+                            type=str, metavar='PATH', action='append', default=[],
+                            help="Mount each readable collection at mountpoint/PATH/UUID and mountpoint/PATH/PDH where PDH is the collection's portable data hash and UUID is its UUID.")
+        mounts.add_argument('--mount-by-tag',
+                            type=str, metavar='PATH', action='append', default=[],
+                            help="Mount all collections with tag TAG at mountpoint/PATH/TAG/UUID.")
+        mounts.add_argument('--mount-home',
+                            type=str, metavar='PATH', action='append', default=[],
+                            help="Mount the current user's home project at mountpoint/PATH.")
+        mounts.add_argument('--mount-shared',
+                            type=str, metavar='PATH', action='append', default=[],
+                            help="Mount projects shared with the current user at mountpoint/PATH.")
+        mounts.add_argument('--mount-tmp',
+                            type=str, metavar='PATH', action='append', default=[],
+                            help="Create a new collection, mount it in read/write mode at mountpoint/PATH, and delete it when unmounting.")
+
+        self.add_argument('--debug', action='store_true', help="""Debug mode""")
+        self.add_argument('--logfile', help="""Write debug logs and errors to the specified file (default stderr).""")
+        self.add_argument('--foreground', action='store_true', help="""Run in foreground (default is to daemonize unless --exec specified)""", default=False)
+        self.add_argument('--encoding', type=str, help="Character encoding to use for filesystem, default is utf-8 (see Python codec registry for list of available encodings)", default="utf-8")
+
+        self.add_argument('--file-cache', type=int, help="File data cache size, in bytes (default 256MiB)", default=256*1024*1024)
+        self.add_argument('--directory-cache', type=int, help="Directory data cache size, in bytes (default 128MiB)", default=128*1024*1024)
+
+        self.add_argument('--read-only', action='store_false', help="Mount will be read only (default)", dest="enable_write", default=False)
+        self.add_argument('--read-write', action='store_true', help="Mount will be read-write", dest="enable_write", default=False)
+
+        self.add_argument('--crunchstat-interval', type=float, help="Write stats to stderr every N seconds (default disabled)", default=0)
+
+        self.add_argument('--exec', type=str, nargs=argparse.REMAINDER,
+                            dest="exec_args", metavar=('command', 'args', '...', '--'),
+                            help="""Mount, run a command, then unmount and exit""")
+
+
+class Mount(object):
+    def __init__(self, args, logger=logging.getLogger('arvados.arv-mount')):
+        self.logger = logger
+        self.args = args
+
+        self.args.mountpoint = os.path.realpath(self.args.mountpoint)
+        if self.args.logfile:
+            self.args.logfile = os.path.realpath(self.args.logfile)
+
+        # Daemonize as early as possible, so we don't accidentally close
+        # file descriptors we're using.
+        self.daemon_ctx = None
+        if not (self.args.exec_args or self.args.foreground):
+            os.chdir(self.args.mountpoint)
+            self.daemon_ctx = daemon.DaemonContext(working_directory='.')
+            self.daemon_ctx.open()
+
+        try:
+            self._setup_logging()
+            self._setup_api()
+            self._setup_mount()
+        except Exception as e:
+            self.logger.exception("arv-mount: exception during setup: %s", e)
+            exit(1)
+
+    def __enter__(self):
+        llfuse.init(self.operations, self.args.mountpoint, self._fuse_options())
+        if self.args.mode != 'by_pdh':
+            self.operations.listen_for_events()
+        t = threading.Thread(None, lambda: llfuse.main())
+        t.start()
+        self.operations.initlock.wait()
+
+    def __exit__(self, exc_type, exc_value, traceback):
+        subprocess.call(["fusermount", "-u", "-z", self.args.mountpoint])
+        self.operations.destroy()
+
+    def Run(self):
+        if self.args.exec_args:
+            self._run_exec(self.args)
+        else:
+            self._run_standalone(self.args)
+
+    def _fuse_options(self):
+        """FUSE mount options; see mount.fuse(8)"""
+        opts = [optname for optname in ['allow_other', 'debug']
+                if getattr(self.args, optname)]
+        # Increase default read/write size from 4KiB to 128KiB
+        opts += ["big_writes", "max_read=131072"]
+        return opts
+
+    def _setup_logging(self):
+        # Configure a log handler based on command-line switches.
+        if self.args.logfile:
+            log_handler = logging.FileHandler(self.args.logfile)
+        elif self.daemon_ctx:
+            log_handler = logging.NullHandler()
+        else:
+            log_handler = None
+
+        if log_handler is not None:
+            arvados.logger.removeHandler(arvados.log_handler)
+            arvados.logger.addHandler(log_handler)
+
+        if self.args.debug:
+            arvados.logger.setLevel(logging.DEBUG)
+            self.logger.debug("arv-mount debugging enabled")
+
+        self.logger.info("enable write is %s", self.args.enable_write)
+
+    def _setup_api(self):
+        self.api = arvados.safeapi.ThreadSafeApiCache(
+            apiconfig=arvados.config.settings(),
+            keep_params={
+                "block_cache": arvados.keep.KeepBlockCache(self.args.file_cache)
+            })
+
+    def _setup_mount(self):
+        self.operations = Operations(
+            os.getuid(),
+            os.getgid(),
+            api_client=self.api,
+            encoding=self.args.encoding,
+            inode_cache=InodeCache(cap=self.args.directory_cache),
+            enable_write=self.args.enable_write)
+
+        if self.args.crunchstat_interval:
+            statsthread = threading.Thread(
+                target=crunchstat.statlogger,
+                args=(self.args.crunchstat_interval,
+                      self.api.keep,
+                      self.operations))
+            statsthread.daemon = True
+            statsthread.start()
+
+        usr = self.api.users().current().execute(num_retries=self.args.retries)
+        now = time.time()
+        dir_class = None
+        dir_args = [llfuse.ROOT_INODE, self.operations.inodes, self.api, self.args.retries]
+        mount_readme = False
+
+        if self.args.mode is not None and (
+                self.args.mount_by_id or
+                self.args.mount_by_pdh or
+                self.args.mount_by_tag or
+                self.args.mount_home or
+                self.args.mount_shared or
+                self.args.mount_tmp or
+                self.args.mount_collection):
+            sys.exit("Cannot combine '{}' mode with custom --mount-* options.".
+                     format(self.args.mode))
+
+        if self.args.mode in ['by_id', 'by_pdh']:
+            # Set up the request handler with the 'magic directory' at the root
+            dir_class = MagicDirectory
+            dir_args.append(self.args.mode == 'by_pdh')
+        elif self.args.mode == 'by_tag':
+            dir_class = TagsDirectory
+        elif self.args.mode == 'shared':
+            dir_class = SharedDirectory
+            dir_args.append(usr)
+        elif self.args.mode == 'home':
+            dir_class = ProjectDirectory
+            dir_args.append(usr)
+            dir_args.append(True)
+        elif self.args.mode == 'all':
+            self.args.mount_by_id = ['by_id']
+            self.args.mount_by_tag = ['by_tag']
+            self.args.mount_home = ['home']
+            self.args.mount_shared = ['shared']
+            mount_readme = True
+        elif self.args.collection is not None:
+            # Set up the request handler with the collection at the root
+            dir_class = CollectionDirectory
+            dir_args.append(self.args.collection)
+        elif self.args.project is not None:
+            dir_class = ProjectDirectory
+            dir_args.append(
+                self.api.groups().get(uuid=self.args.project).execute(
+                    num_retries=self.args.retries))
+
+        if dir_class is not None:
+            self.operations.inodes.add_entry(dir_class(*dir_args))
+            return
+
+        e = self.operations.inodes.add_entry(Directory(
+            llfuse.ROOT_INODE, self.operations.inodes))
+        dir_args[0] = e.inode
+
+        for name in self.args.mount_by_id:
+            self._add_mount(e, name, MagicDirectory(*dir_args, pdh_only=False))
+        for name in self.args.mount_by_pdh:
+            self._add_mount(e, name, MagicDirectory(*dir_args, pdh_only=True))
+        for name in self.args.mount_by_tag:
+            self._add_mount(e, name, TagsDirectory(*dir_args))
+        for name in self.args.mount_home:
+            self._add_mount(e, name, ProjectDirectory(*dir_args, project_object=usr, poll=True))
+        for name in self.args.mount_shared:
+            self._add_mount(e, name, SharedDirectory(*dir_args, exclude=usr, poll=True))
+        for name in self.args.mount_tmp:
+            self._add_mount(e, name, TmpCollectionDirectory(*dir_args))
+
+        if mount_readme:
+            text = self._readme_text(
+                arvados.config.get('ARVADOS_API_HOST'),
+                usr['email'])
+            self._add_mount(e, StringFile(e.inode, text, now))
+
+    def _add_mount(self, tld, name, ent):
+        if name in ['', '.', '..'] or '/' in name:
+            sys.exit("Mount point '{}' is not supported.".format(name))
+        tld._entries[name] = self.operations.inodes.add_entry(ent)
+
+    def _readme_text(self, api_host, user_email):
+        return '''
+Welcome to Arvados!  This directory provides file system access to
+files and objects available on the Arvados installation located at
+'{}' using credentials for user '{}'.
+
+From here, the following directories are available:
+
+  by_id/     Access to Keep collections by uuid or portable data hash (see by_id/README for details).
+  by_tag/    Access to Keep collections organized by tag.
+  home/      The contents of your home project.
+  shared/    Projects shared with you.
+'''.format(api_host, user_email)
+
+    def _run_exec(self):
+        # Initialize the fuse connection
+        llfuse.init(self.operations, self.args.mountpoint, self._fuse_options())
+
+        # Subscribe to change events from API server
+        if self.args.mode != 'by_pdh':
+            self.operations.listen_for_events()
+
+        t = threading.Thread(None, lambda: llfuse.main())
+        t.start()
+
+        # wait until the driver is finished initializing
+        self.operations.initlock.wait()
+
+        rc = 255
+        try:
+            sp = subprocess.Popen(self.args.exec_args, shell=False)
+
+            # forward signals to the process.
+            signal.signal(signal.SIGINT, lambda signum, frame: sp.send_signal(signum))
+            signal.signal(signal.SIGTERM, lambda signum, frame: sp.send_signal(signum))
+            signal.signal(signal.SIGQUIT, lambda signum, frame: sp.send_signal(signum))
+
+            # wait for process to complete.
+            rc = sp.wait()
+
+            # restore default signal handlers.
+            signal.signal(signal.SIGINT, signal.SIG_DFL)
+            signal.signal(signal.SIGTERM, signal.SIG_DFL)
+            signal.signal(signal.SIGQUIT, signal.SIG_DFL)
+        except Exception as e:
+            self.logger.exception(
+                'arv-mount: exception during exec %s', self.args.exec_args)
+            try:
+                rc = e.errno
+            except AttributeError:
+                pass
+        finally:
+            subprocess.call(["fusermount", "-u", "-z", self.args.mountpoint])
+            self.operations.destroy()
+        exit(rc)
+
+    def _run_standalone(self):
+        try:
+            llfuse.init(self.operations, self.args.mountpoint, self._fuse_options())
+
+            # Subscribe to change events from API server
+            self.operations.listen_for_events()
+
+            llfuse.main()
+        except Exception as e:
+            self.logger.exception('arv-mount: exception during mount: %s', e)
+            exit(getattr(e, 'errno', 1))
+        finally:
+            self.operations.destroy()
+        exit(0)
diff --git a/services/fuse/arvados_fuse/crunchstat.py b/services/fuse/arvados_fuse/crunchstat.py
new file mode 100644 (file)
index 0000000..67d2ccc
--- /dev/null
@@ -0,0 +1,63 @@
+import sys
+import time
+
+class Stat(object):
+    def __init__(self, prefix, interval,
+                 egr_name, ing_name,
+                 egr_func, ing_func):
+        self.prefix = prefix
+        self.interval = interval
+        self.egr_name = egr_name
+        self.ing_name = ing_name
+        self.egress = egr_func
+        self.ingress = ing_func
+        self.egr_prev = self.egress()
+        self.ing_prev = self.ingress()
+
+    def update(self):
+        egr = self.egress()
+        ing = self.ingress()
+
+        delta = " -- interval %.4f seconds %d %s %d %s" % (self.interval,
+                                                           egr - self.egr_prev,
+                                                           self.egr_name,
+                                                           ing - self.ing_prev,
+                                                           self.ing_name)
+
+        sys.stderr.write("crunchstat: %s %d %s %d %s%s\n" % (self.prefix,
+                                                             egr,
+                                                             self.egr_name,
+                                                             ing,
+                                                             self.ing_name,
+                                                             delta))
+
+        self.egr_prev = egr
+        self.ing_prev = ing
+
+
+def statlogger(interval, keep, ops):
+    calls = Stat("keepcalls", interval, "put", "get",
+                 keep.put_counter.get,
+                 keep.get_counter.get)
+    net = Stat("net:keep0", interval, "tx", "rx",
+               keep.upload_counter.get,
+               keep.download_counter.get)
+    cache = Stat("keepcache", interval, "hit", "miss",
+               keep.hits_counter.get,
+               keep.misses_counter.get)
+    fuseops = Stat("fuseops", interval,"write", "read",
+                   ops.write_ops_counter.get,
+                   ops.read_ops_counter.get)
+    blk = Stat("blkio:0:0", interval, "write", "read",
+               ops.write_counter.get,
+               ops.read_counter.get)
+
+    while True:
+        time.sleep(interval)
+        calls.update()
+        net.update()
+        cache.update()
+        fuseops.update()
+        blk.update()
+
+
index a6799051bb4794671967a9f6b97853312b2345ac..05b4c50e98c3dac52fbf3c0a07a8229bbade8bed 100755 (executable)
@@ -1,350 +1,7 @@
 #!/usr/bin/env python
 
-import argparse
-import arvados
-import daemon
-import logging
-import os
-import signal
-import subprocess
-import sys
-import time
-
-import arvados.commands._util as arv_cmd
-from arvados_fuse import *
-from arvados.safeapi import ThreadSafeApiCache
-import arvados.keep
-
-logger = logging.getLogger('arvados.arv-mount')
-
-class Stat(object):
-    def __init__(self, prefix, interval,
-                 egr_name, ing_name,
-                 egr_func, ing_func):
-        self.prefix = prefix
-        self.interval = interval
-        self.egr_name = egr_name
-        self.ing_name = ing_name
-        self.egress = egr_func
-        self.ingress = ing_func
-        self.egr_prev = self.egress()
-        self.ing_prev = self.ingress()
-
-    def update(self):
-        egr = self.egress()
-        ing = self.ingress()
-
-        delta = " -- interval %.4f seconds %d %s %d %s" % (self.interval,
-                                                           egr - self.egr_prev,
-                                                           self.egr_name,
-                                                           ing - self.ing_prev,
-                                                           self.ing_name)
-
-        sys.stderr.write("crunchstat: %s %d %s %d %s%s\n" % (self.prefix,
-                                                             egr,
-                                                             self.egr_name,
-                                                             ing,
-                                                             self.ing_name,
-                                                             delta))
-
-        self.egr_prev = egr
-        self.ing_prev = ing
-
-
-def statlogger(interval, keep, ops):
-    calls = Stat("keepcalls", interval, "put", "get",
-                 keep.put_counter.get,
-                 keep.get_counter.get)
-    net = Stat("net:keep0", interval, "tx", "rx",
-               keep.upload_counter.get,
-               keep.download_counter.get)
-    cache = Stat("keepcache", interval, "hit", "miss",
-               keep.hits_counter.get,
-               keep.misses_counter.get)
-    fuseops = Stat("fuseops", interval,"write", "read",
-                   ops.write_ops_counter.get,
-                   ops.read_ops_counter.get)
-    blk = Stat("blkio:0:0", interval, "write", "read",
-               ops.write_counter.get,
-               ops.read_counter.get)
-
-    while True:
-        time.sleep(interval)
-        calls.update()
-        net.update()
-        cache.update()
-        fuseops.update()
-        blk.update()
-
+import arvados_fuse
 
 if __name__ == '__main__':
-    # Handle command line parameters
-    parser = argparse.ArgumentParser(
-        parents=[arv_cmd.retry_opt],
-        description='''Mount Keep data under the local filesystem.  Default mode is --home''',
-        epilog="""
-Note: When using the --exec feature, you must either specify the
-mountpoint before --exec, or mark the end of your --exec arguments
-with "--".
-""")
-    parser.add_argument('mountpoint', type=str, help="""Mount point.""")
-    parser.add_argument('--allow-other', action='store_true',
-                        help="""Let other users read the mount""")
-
-    mount_mode = parser.add_mutually_exclusive_group()
-
-    mount_mode.add_argument('--all', action='store_const', const='all', dest='mode',
-                            help="""Mount a subdirectory for each mode: home, shared, by_tag, by_id (default if no --mount-* arguments are given).""")
-    mount_mode.add_argument('--custom', action='store_const', const=None, dest='mode',
-                            help="""Mount a top level meta-directory with subdirectories as specified by additional --mount-* arguments (default if any --mount-* arguments are given).""")
-    mount_mode.add_argument('--home', action='store_const', const='home', dest='mode',
-                            help="""Mount only the user's home project.""")
-    mount_mode.add_argument('--shared', action='store_const', const='shared', dest='mode',
-                            help="""Mount only list of projects shared with the user.""")
-    mount_mode.add_argument('--by-tag', action='store_const', const='by_tag', dest='mode',
-                            help="""Mount subdirectories listed by tag.""")
-    mount_mode.add_argument('--by-id', action='store_const', const='by_id', dest='mode',
-                            help="""Mount subdirectories listed by portable data hash or uuid.""")
-    mount_mode.add_argument('--by-pdh', action='store_const', const='by_pdh', dest='mode',
-                            help="""Mount subdirectories listed by portable data hash.""")
-    mount_mode.add_argument('--project', type=str, metavar='UUID',
-                            help="""Mount the specified project.""")
-    mount_mode.add_argument('--collection', type=str, metavar='UUID_or_PDH',
-                            help="""Mount only the specified collection.""")
-
-    mounts = parser.add_argument_group('Custom mount options')
-    mounts.add_argument('--mount-by-pdh',
-                        type=str, metavar='PATH', action='append', default=[],
-                        help="Mount each readable collection at mountpoint/PATH/P where P is the collection's portable data hash.")
-    mounts.add_argument('--mount-by-id',
-                        type=str, metavar='PATH', action='append', default=[],
-                        help="Mount each readable collection at mountpoint/PATH/UUID and mountpoint/PATH/PDH where PDH is the collection's portable data hash and UUID is its UUID.")
-    mounts.add_argument('--mount-by-tag',
-                        type=str, metavar='PATH', action='append', default=[],
-                        help="Mount all collections with tag TAG at mountpoint/PATH/TAG/UUID.")
-    mounts.add_argument('--mount-home',
-                        type=str, metavar='PATH', action='append', default=[],
-                        help="Mount the current user's home project at mountpoint/PATH.")
-    mounts.add_argument('--mount-shared',
-                        type=str, metavar='PATH', action='append', default=[],
-                        help="Mount projects shared with the current user at mountpoint/PATH.")
-    mounts.add_argument('--mount-tmp',
-                        type=str, metavar='PATH', action='append', default=[],
-                        help="Create a new collection, mount it in read/write mode at mountpoint/PATH, and delete it when unmounting.")
-
-    parser.add_argument('--debug', action='store_true', help="""Debug mode""")
-    parser.add_argument('--logfile', help="""Write debug logs and errors to the specified file (default stderr).""")
-    parser.add_argument('--foreground', action='store_true', help="""Run in foreground (default is to daemonize unless --exec specified)""", default=False)
-    parser.add_argument('--encoding', type=str, help="Character encoding to use for filesystem, default is utf-8 (see Python codec registry for list of available encodings)", default="utf-8")
-
-    parser.add_argument('--file-cache', type=int, help="File data cache size, in bytes (default 256MiB)", default=256*1024*1024)
-    parser.add_argument('--directory-cache', type=int, help="Directory data cache size, in bytes (default 128MiB)", default=128*1024*1024)
-
-    parser.add_argument('--read-only', action='store_false', help="Mount will be read only (default)", dest="enable_write", default=False)
-    parser.add_argument('--read-write', action='store_true', help="Mount will be read-write", dest="enable_write", default=False)
-
-    parser.add_argument('--crunchstat-interval', type=float, help="Write stats to stderr every N seconds (default disabled)", default=0)
-
-    parser.add_argument('--exec', type=str, nargs=argparse.REMAINDER,
-                        dest="exec_args", metavar=('command', 'args', '...', '--'),
-                        help="""Mount, run a command, then unmount and exit""")
-
-    args = parser.parse_args()
-    args.mountpoint = os.path.realpath(args.mountpoint)
-    if args.logfile:
-        args.logfile = os.path.realpath(args.logfile)
-
-    # Daemonize as early as possible, so we don't accidentally close
-    # file descriptors we're using.
-    if not (args.exec_args or args.foreground):
-        os.chdir(args.mountpoint)
-        daemon_ctx = daemon.DaemonContext(working_directory='.')
-        daemon_ctx.open()
-    else:
-        daemon_ctx = None
-
-    # Configure a log handler based on command-line switches.
-    if args.logfile:
-        log_handler = logging.FileHandler(args.logfile)
-    elif daemon_ctx:
-        log_handler = logging.NullHandler()
-    else:
-        log_handler = None
-
-    if log_handler is not None:
-        arvados.logger.removeHandler(arvados.log_handler)
-        arvados.logger.addHandler(log_handler)
-
-    if args.debug:
-        arvados.logger.setLevel(logging.DEBUG)
-        logger.debug("arv-mount debugging enabled")
-
-    logger.info("enable write is %s", args.enable_write)
-
-    try:
-        api = ThreadSafeApiCache(apiconfig=arvados.config.settings(),
-                                 keep_params={"block_cache": arvados.keep.KeepBlockCache(args.file_cache)})
-
-        # Create the request handler
-        operations = Operations(os.getuid(),
-                                os.getgid(),
-                                api_client=api,
-                                encoding=args.encoding,
-                                inode_cache=InodeCache(cap=args.directory_cache),
-                                enable_write=args.enable_write)
-
-        if args.crunchstat_interval:
-            statsthread = threading.Thread(target=statlogger, args=(args.crunchstat_interval, api.keep, operations))
-            statsthread.daemon = True
-            statsthread.start()
-
-        usr = api.users().current().execute(num_retries=args.retries)
-        now = time.time()
-        dir_class = None
-        dir_args = [llfuse.ROOT_INODE, operations.inodes, api, args.retries]
-        mount_readme = False
-
-        if args.mode is not None and (
-                args.mount_by_id or
-                args.mount_by_pdh or
-                args.mount_by_tag or
-                args.mount_home or
-                args.mount_shared or
-                args.mount_tmp or
-                args.mount_collection):
-            sys.exit("Cannot combine '{}' mode with custom --mount-* options.".
-                     format(args.mode))
-
-        if args.mode in ['by_id', 'by_pdh']:
-            # Set up the request handler with the 'magic directory' at the root
-            dir_class = MagicDirectory
-            dir_args.append(args.mode == 'by_pdh')
-        elif args.mode == 'by_tag':
-            dir_class = TagsDirectory
-        elif args.mode == 'shared':
-            dir_class = SharedDirectory
-            dir_args.append(usr)
-        elif args.mode == 'home':
-            dir_class = ProjectDirectory
-            dir_args.append(usr)
-            dir_args.append(True)
-        elif args.mode == 'all':
-            args.mount_by_id = ['by_id']
-            args.mount_by_tag = ['by_tag']
-            args.mount_home = ['home']
-            args.mount_shared = ['shared']
-            mount_readme = True
-        elif args.collection is not None:
-            # Set up the request handler with the collection at the root
-            dir_class = CollectionDirectory
-            dir_args.append(args.collection)
-        elif args.project is not None:
-            dir_class = ProjectDirectory
-            dir_args.append(api.groups().get(uuid=args.project).execute(
-                    num_retries=args.retries))
-
-        if dir_class is not None:
-            operations.inodes.add_entry(dir_class(*dir_args))
-        else:
-            e = operations.inodes.add_entry(Directory(llfuse.ROOT_INODE, operations.inodes))
-            dir_args[0] = e.inode
-
-            def addMount(tld, name, ent):
-                if name in ['', '.', '..'] or '/' in name:
-                    sys.exit("Mount point '{}' is not supported.".format(name))
-                tld._entries[name] = operations.inodes.add_entry(ent)
-
-            for name in args.mount_by_id:
-                addMount(e, name, MagicDirectory(*dir_args, pdh_only=False))
-            for name in args.mount_by_pdh:
-                addMount(e, name, MagicDirectory(*dir_args, pdh_only=True))
-            for name in args.mount_by_tag:
-                addMount(e, name, TagsDirectory(*dir_args))
-            for name in args.mount_home:
-                addMount(e, name, ProjectDirectory(*dir_args, project_object=usr, poll=True))
-            for name in args.mount_shared:
-                addMount(e, name, SharedDirectory(*dir_args, exclude=usr, poll=True))
-            for name in args.mount_tmp:
-                addMount(e, name, TmpCollectionDirectory(*dir_args))
-
-            if mount_readme:
-                text = '''
-Welcome to Arvados!  This directory provides file system access to
-files and objects available on the Arvados installation located at
-'{}' using credentials for user '{}'.
-
-From here, the following directories are available:
-
-  by_id/     Access to Keep collections by uuid or portable data hash (see by_id/README for details).
-  by_tag/    Access to Keep collections organized by tag.
-  home/      The contents of your home project.
-  shared/    Projects shared with you.
-'''.format(arvados.config.get('ARVADOS_API_HOST'), usr['email'])
-                addMount(e, StringFile(e.inode, text, now))
-
-    except Exception:
-        logger.exception("arv-mount: exception during API setup")
-        exit(1)
-
-    # FUSE options, see mount.fuse(8)
-    opts = [optname for optname in ['allow_other', 'debug']
-            if getattr(args, optname)]
-
-    # Increase default read/write size from 4KiB to 128KiB
-    opts += ["big_writes", "max_read=131072"]
-
-    if args.exec_args:
-        # Initialize the fuse connection
-        llfuse.init(operations, args.mountpoint, opts)
-
-        # Subscribe to change events from API server
-        if args.mode != 'by_pdh':
-            operations.listen_for_events()
-
-        t = threading.Thread(None, lambda: llfuse.main())
-        t.start()
-
-        # wait until the driver is finished initializing
-        operations.initlock.wait()
-
-        rc = 255
-        try:
-            sp = subprocess.Popen(args.exec_args, shell=False)
-
-            # forward signals to the process.
-            signal.signal(signal.SIGINT, lambda signum, frame: sp.send_signal(signum))
-            signal.signal(signal.SIGTERM, lambda signum, frame: sp.send_signal(signum))
-            signal.signal(signal.SIGQUIT, lambda signum, frame: sp.send_signal(signum))
-
-            # wait for process to complete.
-            rc = sp.wait()
-
-            # restore default signal handlers.
-            signal.signal(signal.SIGINT, signal.SIG_DFL)
-            signal.signal(signal.SIGTERM, signal.SIG_DFL)
-            signal.signal(signal.SIGQUIT, signal.SIG_DFL)
-        except Exception as e:
-            logger.exception('arv-mount: exception during exec %s',
-                             args.exec_args)
-            try:
-                rc = e.errno
-            except AttributeError:
-                pass
-        finally:
-            subprocess.call(["fusermount", "-u", "-z", args.mountpoint])
-            operations.destroy()
-
-        exit(rc)
-    else:
-        try:
-            llfuse.init(operations, args.mountpoint, opts)
-
-            # Subscribe to change events from API server
-            operations.listen_for_events()
-
-            llfuse.main()
-        except Exception as e:
-            logger.exception('arv-mount: exception during mount')
-            exit(getattr(e, 'errno', 1))
-        finally:
-            operations.destroy()
+    args = arvados_fuse.command.ArgumentParser().parse_args()
+    arvados_fuse.command.Mount(args).Run()