Enable extensions to control the file_to_run

jupyter_server/extension/application.py

@@ -186,6 +186,8 @@ def get_extension_point(cls):
     def _default_url(self):
         return self.extension_url
 
+    file_url_prefix = Unicode('notebooks')
+
     # Is this linked to a serverapp yet?
     _linked = Bool(False)
 
@@ -337,7 +339,8 @@ def _jupyter_server_config(self):
         base_config = {
             "ServerApp": {
                 "default_url": self.default_url,
-                "open_browser": self.open_browser
+                "open_browser": self.open_browser,
+                "file_url_prefix": self.file_url_prefix
             }
         }
         base_config["ServerApp"].update(self.serverapp_config)

jupyter_server/pytest_plugin.py

@@ -278,9 +278,7 @@ def jp_serverapp(
     """Starts a Jupyter Server instance based on the established configuration values."""
     app = jp_configurable_serverapp(config=jp_server_config, argv=jp_argv)
     yield app
-    app.remove_server_info_file()
-    app.remove_browser_open_file()
-    app.cleanup_kernels()
+    app._cleanup()
 
 
 @pytest.fixture

jupyter_server/serverapp.py

@@ -32,6 +32,7 @@
 import webbrowser
 import urllib
 import inspect
+import pathlib
 
 from base64 import encodebytes
 try:
@@ -102,7 +103,13 @@
 from jupyter_server._sysinfo import get_sys_info
 
 from ._tz import utcnow, utcfromtimestamp
-from .utils import url_path_join, check_pid, url_escape, urljoin, pathname2url
+from .utils import (
+    url_path_join,
+    check_pid,
+    url_escape,
+    urljoin,
+    pathname2url
+)
 
 from jupyter_server.extension.serverextension import ServerExtensionApp
 from jupyter_server.extension.manager import ExtensionManager
@@ -620,10 +627,15 @@ def _default_log_format(self):
         return u"%(color)s[%(levelname)1.1s %(asctime)s.%(msecs).03d %(name)s]%(end_color)s %(message)s"
 
     # file to be opened in the Jupyter server
-    file_to_run = Unicode('', config=True)
+    file_to_run = Unicode('',
+        help="Open the named file when the application is launched."
+    ).tag(config=True)
 
-    # Network related information
+    file_url_prefix = Unicode('notebooks',
+        help="The URL prefix where files are opened directly."
+    ).tag(config=True)
 
+    # Network related information
     allow_origin = Unicode('', config=True,
         help="""Set the Access-Control-Allow-Origin header
 
@@ -1195,6 +1207,13 @@ def _default_browser_open_file(self):
         basename = "jpserver-%s-open.html" % os.getpid()
         return os.path.join(self.runtime_dir, basename)
 
+    browser_open_file_to_run = Unicode()
+
+    @default('browser_open_file_to_run')
+    def _default_browser_open_file_to_run(self):
+        basename = "jpserver-file-to-run-%s-open.html" % os.getpid()
+        return os.path.join(self.runtime_dir, basename)
+
     pylab = Unicode('disabled', config=True,
         help=_("""
         DISABLED: use %pylab or %matplotlib in the notebook to enable matplotlib.
@@ -1254,7 +1273,7 @@ def _root_dir_validate(self, proposal):
             # If we receive a non-absolute path, make it absolute.
             value = os.path.abspath(value)
         if not os.path.isdir(value):
-            raise TraitError(trans.gettext("No such notebook dir: '%r'") % value)
+            raise TraitError(trans.gettext("No such directory: '%r'") % value)
         return value
 
     @observe('root_dir')
@@ -1874,10 +1893,71 @@ def remove_server_info_file(self):
             os.unlink(self.info_file)
         except OSError as e:
             if e.errno != errno.ENOENT:
-                raise
+                raise;
+
+    def _resolve_file_to_run_and_root_dir(self):
+        """Returns a relative path from file_to_run
+        to root_dir. If root_dir and file_to_run
+        are incompatible, i.e. on different subtrees,
+        crash the app and log a critical message. Note
+        that if root_dir is not configured and file_to_run
+        is configured, root_dir will be set to the parent
+        directory of file_to_run.
+        """
+        rootdir_abspath = pathlib.Path(self.root_dir).resolve()
+        file_rawpath = pathlib.Path(self.file_to_run)
+        combined_path = (rootdir_abspath / file_rawpath).resolve()
+        is_child = str(combined_path).startswith(str(rootdir_abspath))
+
+        if is_child:
+            if combined_path.parent != rootdir_abspath:
+                self.log.debug(
+                    "The `root_dir` trait is set to a directory that's not "
+                    "the immediate parent directory of `file_to_run`. Note that "
+                    "the server will start at `root_dir` and open the "
+                    "the file from the relative path to the `root_dir`."
+                )
+            return str(combined_path.relative_to(rootdir_abspath))
+
+        self.log.critical(
+            "`root_dir` and `file_to_run` are incompatible. They "
+            "don't share the same subtrees. Make sure `file_to_run` "
+            "is on the same path as `root_dir`."
+        )
+        self.exit(1)
+
+    def _write_browser_open_file(self, url, fh):
+        if self.token:
+            url = url_concat(url, {'token': self.token})
+        url = url_path_join(self.connection_url, url)
+
+        jinja2_env = self.web_app.settings['jinja2_env']
+        template = jinja2_env.get_template('browser-open.html')
+        fh.write(template.render(open_url=url, base_url=self.base_url))
+
+    def write_browser_open_files(self):
+        """Write an `browser_open_file` and `browser_open_file_to_run` files
+
+        This can be used to open a file directly in a browser.
+        """
+        # default_url contains base_url, but so does connection_url
+        self.write_browser_open_file()
+
+        # Create a second browser open file if
+        # file_to_run is set.
+        if self.file_to_run:
+            # Make sure file_to_run and root_dir are compatible.
+            file_to_run_relpath = self._resolve_file_to_run_and_root_dir()
+
+            file_open_url = url_escape(
+                url_path_join(self.file_url_prefix, *file_to_run_relpath.split(os.sep))
+            )
+
+            with open(self.browser_open_file_to_run, 'w', encoding='utf-8') as f:
+                self._write_browser_open_file(file_open_url, f)
 
     def write_browser_open_file(self):
-        """Write an nbserver-<pid>-open.html file
+        """Write an jpserver-<pid>-open.html file
 
         This can be used to open the notebook in a browser
         """
@@ -1887,17 +1967,21 @@ def write_browser_open_file(self):
         with open(self.browser_open_file, 'w', encoding='utf-8') as f:
             self._write_browser_open_file(open_url, f)
 
-    def _write_browser_open_file(self, url, fh):
-        if self.token:
-            url = url_concat(url, {'token': self.token})
-        url = url_path_join(self.connection_url, url)
+    def remove_browser_open_files(self):
+        """Remove the `browser_open_file` and `browser_open_file_to_run` files
+        created for this server.
 
-        jinja2_env = self.web_app.settings['jinja2_env']
-        template = jinja2_env.get_template('browser-open.html')
-        fh.write(template.render(open_url=url, base_url=self.base_url))
+        Ignores the error raised when the file has already been removed.
+        """
+        self.remove_browser_open_file()
+        try:
+            os.unlink(self.browser_open_file_to_run)
+        except OSError as e:
+            if e.errno != errno.ENOENT:
+                raises
 
     def remove_browser_open_file(self):
-        """Remove the nbserver-<pid>-open.html file created for this server.
+        """Remove the jpserver-<pid>-open.html file created for this server.
 
         Ignores the error raised when the file has already been removed.
         """
@@ -1907,42 +1991,40 @@ def remove_browser_open_file(self):
             if e.errno != errno.ENOENT:
                 raise
 
-    def launch_browser(self):
-        try:
-            browser = webbrowser.get(self.browser or None)
-        except webbrowser.Error as e:
-            self.log.warning(_('No web browser found: %s.') % e)
-            browser = None
-
-        if not browser:
-            return
-
+    def _prepare_browser_open(self):
         if not self.use_redirect_file:
             uri = self.default_url[len(self.base_url):]
 
             if self.token:
                 uri = url_concat(uri, {'token': self.token})
 
         if self.file_to_run:
-            if not os.path.exists(self.file_to_run):
-                self.log.critical(_("%s does not exist") % self.file_to_run)
-                self.exit(1)
-
-            relpath = os.path.relpath(self.file_to_run, self.root_dir)
-            uri = url_escape(url_path_join('notebooks', *relpath.split(os.sep)))
-
-            # Write a temporary file to open in the browser
-            fd, open_file = tempfile.mkstemp(suffix='.html')
-            with open(fd, 'w', encoding='utf-8') as fh:
-                self._write_browser_open_file(uri, fh)
+            # Create a separate, temporary open-browser-file
+            # pointing at a specific file.
+            open_file = self.browser_open_file_to_run
         else:
+            # otherwise, just return the usual open browser file.
             open_file = self.browser_open_file
 
         if self.use_redirect_file:
             assembled_url = urljoin('file:', pathname2url(open_file))
         else:
             assembled_url = url_path_join(self.connection_url, uri)
 
+        return assembled_url, open_file
+
+    def launch_browser(self):
+        try:
+            browser = webbrowser.get(self.browser or None)
+        except webbrowser.Error as e:
+            self.log.warning(_('No web browser found: %s.') % e)
+            browser = None
+
+        if not browser:
+            return
+
+        assembled_url, _ = self._prepare_browser_open()
+
         b = lambda: browser.open(assembled_url, new=self.webbrowser_open_new)
         threading.Thread(target=b).start()
 
@@ -1970,7 +2052,7 @@ def start_app(self):
                  "resources section at https://jupyter.org/community.html."))
 
         self.write_server_info_file()
-        self.write_browser_open_file()
+        self.write_browser_open_files()
 
         # Handle the browser opening.
         if self.open_browser:
@@ -1987,6 +2069,14 @@ def start_app(self):
                 '    %s' % self.display_url,
             ]))
 
+    def _cleanup(self):
+        """General cleanup of files and kernels created
+        by this instance ServerApp.
+        """
+        self.remove_server_info_file()
+        self.remove_browser_open_files()
+        self.cleanup_kernels()
+
     def start_ioloop(self):
         """Start the IO Loop."""
         self.io_loop = ioloop.IOLoop.current()
@@ -2000,9 +2090,7 @@ def start_ioloop(self):
         except KeyboardInterrupt:
             self.log.info(_("Interrupted..."))
         finally:
-            self.remove_server_info_file()
-            self.remove_browser_open_file()
-            self.cleanup_kernels()
+            self._cleanup()
 
     def start(self):
         """ Start the Jupyter server app, after initialization

tests/test_serverapp.py

@@ -1,5 +1,6 @@
 import os
 import getpass
+import pathlib
 import pytest
 import logging
 from unittest.mock import patch
@@ -117,3 +118,93 @@ def test_list_running_servers(jp_serverapp, jp_web_app):
     servers = list(list_running_servers(jp_serverapp.runtime_dir))
     assert len(servers) >= 1
 
+
+@pytest.fixture
+def prefix_path(jp_root_dir, tmp_path):
+    """If a given path is prefixed with the literal
+    strings `/jp_root_dir` or `/tmp_path`, replace those
+    strings with these fixtures.
+
+    Returns a pathlib Path object.
+    """
+    def _inner(rawpath):
+        path = pathlib.PurePosixPath(rawpath)
+        if rawpath.startswith('/jp_root_dir'):
+            path = jp_root_dir.joinpath(*path.parts[2:])
+        elif rawpath.startswith('/tmp_path'):
+            path = tmp_path.joinpath(*path.parts[2:])
+        return pathlib.Path(path)
+    return _inner
+
+
+@pytest.mark.parametrize(
+    "root_dir,file_to_run,expected_output",
+    [
+        (
+            None,
+            'notebook.ipynb',
+            'notebook.ipynb'
+        ),
+        (
+            None,
+            '/tmp_path/path/to/notebook.ipynb',
+            'notebook.ipynb'
+        ),
+        (
+            '/jp_root_dir',
+            '/tmp_path/path/to/notebook.ipynb',
+            SystemExit
+        ),
+        (
+            '/tmp_path',
+            '/tmp_path/path/to/notebook.ipynb',
+            'path/to/notebook.ipynb'
+        ),
+        (
+            '/jp_root_dir',
+            'notebook.ipynb',
+            'notebook.ipynb'
+        ),
+        (
+            '/jp_root_dir',
+            'path/to/notebook.ipynb',
+            'path/to/notebook.ipynb'
+        ),
+    ]
+)
+def test_resolve_file_to_run_and_root_dir(
+    prefix_path,
+    root_dir,
+    file_to_run,
+    expected_output
+):
+    # Verify that the Singleton instance is cleared before the test runs.
+    ServerApp.clear_instance()
+
+    # Setup the file_to_run path, in case the server checks
+    # if the directory exists before initializing the server.
+    file_to_run = prefix_path(file_to_run)
+    if file_to_run.is_absolute():
+        file_to_run.parent.mkdir(parents=True, exist_ok=True)
+    kwargs = {"file_to_run": str(file_to_run)}
+
+    # Setup the root_dir path, in case the server checks
+    # if the directory exists before initializing the server.
+    if root_dir:
+        root_dir = prefix_path(root_dir)
+        if root_dir.is_absolute():
+            root_dir.parent.mkdir(parents=True, exist_ok=True)
+        kwargs["root_dir"] = str(root_dir)
+
+    # Create the notebook in the given location
+    serverapp = ServerApp.instance(**kwargs)
+
+    if expected_output is SystemExit:
+        with pytest.raises(SystemExit):
+            serverapp._resolve_file_to_run_and_root_dir()
+    else:
+        relpath = serverapp._resolve_file_to_run_and_root_dir()
+        assert relpath == str(pathlib.Path(expected_output))
+
+    # Clear the singleton instance after each run.
+    ServerApp.clear_instance()