Support for serving multiple apps with index with Bokeh and/ or Panel Server

.gitignore

@@ -6,3 +6,5 @@ dist/
 *.egg-info
 .vscode
 
+.venv
+

README.md

@@ -1,33 +1,36 @@
 # bokeh-root-cmd
 
-Command line wrapper to run a named Bokeh script/folder as root URL.
+Command line wrapper to run one or more named Bokeh/Panel scripts/folders as root URL.
 
-This project is used in [ContainDS Dashboards](https://github.com/ideonate/cdsdashboards), which is a user-friendly 
-way to launch Jupyter notebooks as shareable dashboards inside JupyterHub. Also works with Streamlit and other 
-visualization frameworks.
+This project is used in [ContainDS Dashboards](https://github.com/ideonate/cdsdashboards), which is a user-friendly
+way to launch Jupyter notebooks as shareable dashboards inside JupyterHub. Also works with Bokeh, Dash, Panel, Streamlit and other visualization frameworks.
 
 ## Install and Run
 
 Install using pip.
 
-```
+```bash
 pip install bokeh-root-cmd
 ```
 
 The file to start is specified on the command line, for example:
 
-```
+```bash
 bokeh-root-cmd ~/Dev/mybokehscript.py
 ```
 
-By default the server will listen on port 8888
-
-To specify a different port, use the --port flag.
+By default the server will listen on port 8888. To specify a different **port**, use the --port flag.
 
-```
+```bash
 bokeh-root-cmd --port=8888 ~/Dev/mybokehscript.py
 ```
 
+To use the Panel server use the --server flag.
+
+```bash
+bokeh-root-cmd --server=panel ~/Dev/mybokehscript.py
+```
+
 To run directly in python: `python -m bokeh_root_cmd.main <rest of command line>`
 
 ## Other command line args
@@ -37,3 +40,33 @@ To run directly in python: `python -m bokeh_root_cmd.main <rest of command line>
 --debug
 
 --ip
+
+## Tests
+
+In order to be able to test manually you would need to `pip install panel pytest`. This will also install bokeh.
+
+### Automated Tests
+
+```bash
+pytest tests.py
+```
+
+### Single File on Bokeh Server
+
+Run `bokeh-root-cmd test_apps/test_bokeh_hello.py` and verify the app is running at `http://localhost:8888`.
+
+### Single File on Panel Server
+
+Run `bokeh-root-cmd --server=panel test_apps/test_panel_hello.py` and verify the app is running at `http://localhost:8888`.
+
+### Multiple Files on Bokeh Server
+
+Run `bokeh-root-cmd test_apps/*.py` and verify the app index is running at `http://localhost:8888` and test apps at `http://localhost:8888/test_bokeh_hello` and `http://localhost:8888/test_panel_hello`.
+
+### Multiple Files on Panel Server
+
+Run `bokeh-root-cmd --server=panel test_apps/*.py` and verify the app index is running at `http://localhost:8888` and test apps at `http://localhost:8888/test_bokeh_hello` and `http://localhost:8888/test_panel_hello`. Note that no `ready-check' app is included in the index list.
+
+You can also specify them individually
+
+Run `bokeh-root-cmd --server=panel test_apps/test_bokeh_hello.py test_apps/test_panel_hello.py` and verify the app index is running at `http://localhost:8888` and test apps at `http://localhost:8888/test_bokeh_hello` and `http://localhost:8888/test_panel_hello`. Note that no `ready-check' app is included in the index list.

bokeh_root_cmd/main.py

@@ -1,61 +1,156 @@
-import os
+"""Command line wrapper to serve one or more named Bokeh scripts or folders."""
 import logging
+import os
+import pathlib
+from typing import Any, Dict, Tuple
 
-from bokeh.command.util import build_single_handler_application
-from bokeh.server.server import Server
+import bokeh.server.views
 import click
+from bokeh.application.application import Application
+from bokeh.command.util import build_single_handler_application
+from bokeh.server.server import Server as _BkServer
+from bokeh.server.views.root_handler import RootHandler
+from panel.io.server import INDEX_HTML as _PANEL_INDEX_HTML
+from panel.io.server import Server as _PnServer
+import logging
 
 from .readycheck import create_ready_app
 
-class BokehException(Exception):
-    pass
+FORMAT = '%(asctime)s - %(name)s - %(levelname)s - %(message)s'
 
-def make_app(command, debug=False):
+logging.basicConfig(format=FORMAT)
+root_logger = logging.getLogger()
+root_logger.setLevel(logging.INFO)
 
-    # Command can be absolute, or could be relative to cwd
-    app_py_path = os.path.join(os.getcwd(), command)
+logger = logging.getLogger('bokeh_root_cmd')
 
-    print("Fetching Bokeh script or folder {}".format(app_py_path))
+_BOKEH_INDEX_HTML = str(pathlib.Path(bokeh.server.views.__file__).parent / "app_index.html")
+class BokehServer:
+    index_html = _BOKEH_INDEX_HTML
+    server_class = _BkServer
 
-    dirname = os.path.dirname(app_py_path)
+    @staticmethod
+    def _make_app(command: str, url: str = "/", debug: bool = False) -> Application:
+        cwd_original = os.getcwd()
 
-    if os.path.isdir(dirname):
-        print("CWD to {}".format(dirname))
-        os.chdir(dirname)
+        # Command can be absolute, or could be relative to cwd
+        app_py_path = os.path.join(os.getcwd(), command)
 
-    app = build_single_handler_application(app_py_path, ['/'])
+        dirname = os.path.dirname(app_py_path)
 
-    return app
+        if app_py_path==dirname:
+            logger.debug("Fetching folder {}".format(app_py_path))
+        else:
+            logger.debug("Fetching script {}".format(app_py_path))
 
+        if os.path.isdir(dirname):
+            logger.debug("Changing working dir to {}".format(dirname))
+            os.chdir(dirname)
 
-@click.command()
-@click.option('--port', default=8888, type=click.INT, help='port for the proxy server to listen on')
-@click.option('--ip', default=None, help='Address to listen on')
-@click.option('--allow-websocket-origin', default=None, multiple=True, help='Web socket origins allowed')
-@click.option('--debug/--no-debug', default=False, help='To display debug level logs')
-@click.argument('command', nargs=1, required=True)
-def run(port, ip, debug, allow_websocket_origin, command):
+        app = build_single_handler_application(app_py_path, [url])
 
-    if debug:
-        print('Setting debug')
+        os.chdir(cwd_original)
+        logger.debug("Changing working dir back to {}".format(cwd_original))
 
-    app = make_app(command, debug)
+        return app
 
-    server_kwargs = {'port': port, 'ip': ip}
+    @classmethod
+    def _get_applications(cls, command: Tuple[str], debug=False) -> Dict[str, Application]:
+        apps = {}
+        if len(command) == 1:
+            apps = {"/": cls._make_app(command[0], debug)}
+        elif len(command) > 1:
+            for cmd in command:
+                application = cls._make_app(cmd, debug)
+                route = application.handlers[0].url_path()
+                apps[route] = application
+        return apps
 
-    if allow_websocket_origin:
-        server_kwargs['allow_websocket_origin'] = list(allow_websocket_origin)
+    @classmethod
+    def _get_server_kwargs(cls, port, ip, allow_websocket_origin, command) -> Dict[str, Any]:
+        server_kwargs = {"port": port, "ip": ip}
+        if allow_websocket_origin:
+            server_kwargs["allow_websocket_origin"] = list(allow_websocket_origin)
+        if len(command) > 1:
+            server_kwargs.update(
+                {"use_index": True, "redirect_root": True, "index": cls.index_html}
+            )
+        return server_kwargs
 
-    server = Server({'/': app, '/ready-check': create_ready_app()}, **server_kwargs)
+    def run(self, port, ip, debug, allow_websocket_origin, command):
+        logger.info("Starting %s", type(self).__name__)
+        if debug:
+            root_logger.setLevel(logging.DEBUG)
 
-    server.run_until_shutdown()
+        logger.debug("ip = %s", ip)
+        logger.debug("port = %s", port)
+        logger.debug("debug = %s", debug)
+        logger.debug("allow_websocket_origin = %s", allow_websocket_origin)
+        logger.debug("command = %s", command)
 
-
-if __name__ == '__main__':
+        applications = self._get_applications(command, debug)
+        applications["/ready-check"] = create_ready_app()
+        logger.debug("applications = %s", list(applications.keys()))
 
-    try:
+        server_kwargs = self._get_server_kwargs(port, ip, allow_websocket_origin, command)
+        if debug:
+            server_kwargs["log_level"]="debug"
+        server_kwargs["log_format"]=FORMAT
+        logger.debug("server_kwargs = %s", server_kwargs)
 
-        run()
+        server = self.server_class(applications, **server_kwargs)
 
+        server.run_until_shutdown()
+
+
+class PanelServer(BokehServer):
+    index_html = _PANEL_INDEX_HTML
+    server_class = _PnServer
+
+
+@click.command()
+@click.option("--port", default=8888, type=click.INT, help="port for the proxy server to listen on")
+@click.option("--ip", default=None, help="Address to listen on")
+@click.option(
+    "--allow-websocket-origin", default=None, multiple=True, help="Web socket origins allowed"
+)
+@click.option("--debug/--no-debug", default=False, help="To display debug level logs")
+@click.option(
+    "--server", default="bokeh", type=click.STRING, help="The server to use. One of bokeh or panel. Default is bokeh."
+)
+@click.argument("command", nargs=-1, required=True)
+def run(port, ip, debug, allow_websocket_origin, server, command):
+    if server=="panel":
+        server = PanelServer()
+    else:
+        server = BokehServer()
+
+    server.run(
+        port=port,
+        ip=ip,
+        debug=debug,
+        allow_websocket_origin=allow_websocket_origin,
+        command=command,
+    )
+
+
+# Bokeh/ Panel can serve an index page with a list of applications at "/"
+# The below is a workaround to avoid including the 'ready-check' application
+def _root_handler_initialize_without_ready_check(self, *args, **kw):
+        kw["applications"]=kw["applications"].copy()
+        if "/ready-check" in kw["applications"]:
+            kw["applications"].pop("/ready-check")
+
+        self.applications = kw["applications"]
+        self.prefix = kw["prefix"]
+        self.index = kw["index"]
+        self.use_redirect = kw["use_redirect"]
+
+RootHandler.initialize = _root_handler_initialize_without_ready_check
+
+
+if __name__ == "__main__":
+    try:
+        run()
     except SystemExit as se:
-        print('Caught SystemExit {}'.format(se))
+        logger.error("Caught SystemExit {}".format(se))

requirements.txt

@@ -1 +1,3 @@
 Click>=7.0
+bokeh
+panel

test_apps/test_bokeh_hello.py

@@ -0,0 +1,23 @@
+from bokeh.models import ColumnDataSource
+from bokeh.plotting import figure
+from bokeh.io import curdoc
+
+def modify_doc(doc):
+    """Add a plotted function to the document.
+
+    Arguments:
+        doc: A bokeh document to which elements can be added.
+    """
+    x_values = range(10)
+    y_values = [x ** 2 for x in x_values]
+    data_source = ColumnDataSource(data=dict(x=x_values, y=y_values))
+    plot = figure(title="f(x) = x^2",
+                  tools="crosshair,pan,reset,save,wheel_zoom",)
+    plot.line('x', 'y', source=data_source, line_width=3, line_alpha=0.6)
+    doc.add_root(plot)
+    doc.title = "Hello World"
+
+def main():
+    modify_doc(curdoc())
+
+main()

test_apps/test_panel_hello.py

@@ -0,0 +1,19 @@
+"""We can use this to test the bokeh_root_cmd"""
+import panel as pn
+pn.extension(sizing_mode="stretch_width")
+
+
+def test_panel_app():
+    """Returns a Panel test app that has been marked `.servable()`
+
+    Returns:
+        pn.Column: A Column based Panel app
+    """
+    slider = pn.widgets.FloatSlider(name="Slider")
+    return pn.template.FastListTemplate(
+        title="Panel Test App", sidebar=[slider], main=[slider.param.value]
+    ).servable()
+
+
+if __name__.startswith("bokeh"):
+    test_panel_app()

tests.py

@@ -0,0 +1,63 @@
+"""Test of the main functionality"""
+import pytest
+from bokeh.application.application import Application
+
+from bokeh_root_cmd.main import BokehServer, PanelServer
+
+
+@pytest.fixture(params=[BokehServer, PanelServer])
+def server_class(request):
+    return request.param
+
+def test_get_server_kwargs_single_app(server_class):
+    """Test Case: Starting one app"""
+    actual = server_class._get_server_kwargs(
+        port=7888,
+        ip="0.0.0.0",
+        allow_websocket_origin=("https://awesome-panel.org",),
+        command=("test_apps/test_bokeh_hello.py",),
+    )
+
+    assert actual == {
+        "port": 7888,
+        "ip": "0.0.0.0",
+        "allow_websocket_origin": ["https://awesome-panel.org"],
+    }
+
+
+def test_get_server_kwargs_multiple_apps(server_class):
+    """Test Case: Starting multiple apps"""
+    actual = server_class._get_server_kwargs(
+        port=7888,
+        ip="0.0.0.0",
+        allow_websocket_origin=("https://awesome-panel.org",),
+        command=("test_apps/test_bokeh_hello.py", "test_apps/test_panel_hello.py"),
+    )
+
+    assert actual == {
+        "port": 7888,
+        "ip": "0.0.0.0",
+        "allow_websocket_origin": ["https://awesome-panel.org"],
+        "use_index": True,
+        "redirect_root": True,
+        "index": server_class.index_html,
+    }
+
+
+def test_get_applications_single_app(server_class):
+    """Test Case: Starting one app"""
+    actual = server_class._get_applications(command=("test_apps/test_bokeh_hello.py",), debug=False)
+
+    assert len(actual) == 1
+    assert isinstance(actual["/"], Application)
+
+
+def test_get_applications_multiple_apps(server_class):
+    """Test Case: Starting multiple apps"""
+    actual = server_class._get_applications(
+        command=("test_apps/test_bokeh_hello.py", "test_apps/test_panel_hello.py"), debug=False
+    )
+
+    assert len(actual) == 2
+    assert isinstance(actual["/test_bokeh_hello"], Application)
+    assert isinstance(actual["/test_panel_hello"], Application)