Add support of configuring extension logic using env. variables

README.md

@@ -1,6 +1,9 @@
 # jupyter-rsession-proxy
 
-**jupyter-rsession-proxy** provides Jupyter server and notebook extensions to proxy RStudio.
+[![PyPI](https://img.shields.io/pypi/v/jupyter-rsession-proxy?label=PyPI%20Version)](https://pypi.org/project/jupyter-rsession-proxy/)
+[![PyPI - Wheel](https://img.shields.io/pypi/wheel/jupyter-rsession-proxy)](https://pypi.org/project/jupyter-rsession-proxy/)
+
+**jupyter-rsession-proxy** provides Jupyter server and notebook extensions to proxy RStudio Server (multi-user env.) or RStudio Session (single-user env.).
 
 ![Screenshot](screenshot.png)
 
@@ -25,6 +28,20 @@ Install the library:
 pip install jupyter-rsession-proxy
 ```
 
+## Configuring using environment variables
+
+This extension can be configured using environment variables. 
+Below is a list with all supported environment variables.
+
+| Environment variable  | Description |
+| --------------------- |-------------| 
+| RSTUDIO_RSERVER_BIN   | Prioritized location for searching binary file "rserver". Should be an absolute path to rserver or not set. | 
+| RSTUDIO_RSERVER_ARGS  | Overrides all arguments (except --www-port) for "rserver" binary. | 
+| RSTUDIO_RSESSION_BIN  | Prioritized location for searching binary file "rsession". Should be an absolute path to rserver or not set. |
+| RSTUDIO_RSESSION_ARGS | Overrides all arguments (except --www-port and --user-identity) for "rsession" binary. |
+| RSTUDIO_FOLDER        | Prioritized folder for searching all RStudio related binary files. Should be an absolute path to folder or not set. |
+
+
 ## Example
 
 [rocker/binder](https://hub.docker.com/r/rocker/binder) contains an example installation which you can run on binder.

jupyter_rsession_proxy/__init__.py

@@ -1,50 +1,94 @@
-import os
-import subprocess
+"""
+This file contains logic that is required for "jupyter-server-proxy" to register additional launchers in Jupyter Notebook.
+Docs: https://github.com/jupyterhub/jupyter-server-proxy/blob/master/docs/server-process.rst
+"""
 import getpass
+import os
+import shlex
 import shutil
+import subprocess
+
+
+# RSTUDIO_RSERVER_BIN - Prioritized location for searching binary file "rserver". 
+# Should be an absolute path to rserver or not set.
+RSTUDIO_RSERVER_BIN = os.getenv('RSTUDIO_RSERVER_BIN')
+
+# RSTUDIO_RSERVER_ARGS - Overrides all arguments (except --www-port) for "rserver" binary.
+# Should be an absolute path to rserver or not set.
+RSTUDIO_RSERVER_ARGS = os.getenv('RSTUDIO_RSERVER_ARGS', '')
+
+# RSTUDIO_RSESSION_BIN - Prioritized location for searching binary file "rsession". 
+RSTUDIO_RSESSION_BIN = os.getenv('RSTUDIO_RSESSION_BIN')
+
+# RSTUDIO_RSESSION_ARGS - Overrides all arguments (except --www-port and --user-identity) for "rsession" binary.
+RSTUDIO_RSESSION_ARGS = os.getenv(
+    'RSTUDIO_RSESSION_ARGS', 
+    '--standalone=1 --program-mode=server --log-stderr=1 --session-timeout-minutes=0'
+)
+
+# RSTUDIO_FOLDER - Prioritized folder for searching all RStudio related binary files.
+# Should be an absolute path to folder or not set.
+RSTUDIO_FOLDER = os.getenv('RSTUDIO_FOLDER')
+
 
 def get_rstudio_executable(prog):
+    """Find location (absolute path) of RStudio program"""
+    # Try env. variable RSTUDIO_FOLDER to search prog in
+    if RSTUDIO_FOLDER:
+        bin_location = os.path.join(RSTUDIO_FOLDER, prog)
+        if os.path.exists(bin_location):
+            return bin_location
+
     # Find prog in known locations
     other_paths = [
         # When rstudio-server deb is installed
         os.path.join('/usr/lib/rstudio-server/bin', prog),
         # When just rstudio deb is installed
         os.path.join('/usr/lib/rstudio/bin', prog),
     ]
+
+    # Try to find prog in PATH
     if shutil.which(prog):
         return prog
 
     for op in other_paths:
         if os.path.exists(op):
             return op
 
-    raise FileNotFoundError(f'Could not find {prog} in PATH')
+    raise FileNotFoundError(f'Could not find {prog} in PATH or well known locations')
 
 def get_icon_path():
+    """Get path to icon for Jupyter web interface"""
     return os.path.join(
         os.path.dirname(os.path.abspath(__file__)), 'icons', 'rstudio.svg'
     )
 
 def setup_rserver():
+    """Get entry for RServer"""
     def _get_env(port):
         return dict(USER=getpass.getuser())
 
     def _get_cmd(port):
-        return [
-            get_rstudio_executable('rserver'),
+        bin_file = RSTUDIO_RSERVER_BIN if RSTUDIO_RSERVER_BIN else get_rstudio_executable('rserver')
+        cmd = [
+            bin_file,
             '--www-port=' + str(port)
         ]
+        if RSTUDIO_RSERVER_ARGS:
+            cmd.extend(shlex.split(RSTUDIO_RSERVER_ARGS))
+        return cmd
 
     return {
         'command': _get_cmd,
         'environment': _get_env,
         'launcher_entry': {
-            'title': 'RStudio',
+            'title': 'RStudio Server',
             'icon_path': get_icon_path()
         }
     }
 
 def setup_rsession():
+    """Get entry for RSession"""
     def _get_env(port):
         # Detect various environment variables rsession requires to run
         # Via rstudio's src/cpp/core/r_util/REnvironmentPosix.cpp
@@ -65,21 +109,21 @@ def _get_env(port):
         }
 
     def _get_cmd(port):
-        return [
-            get_rstudio_executable('rsession'),
-            '--standalone=1',
-            '--program-mode=server',
-            '--log-stderr=1',
-            '--session-timeout-minutes=0',
+        bin_file = RSTUDIO_RSESSION_BIN if RSTUDIO_RSESSION_BIN else get_rstudio_executable('rsession')
+        cmd = [
+            bin_file,
             '--user-identity=' + getpass.getuser(),
             '--www-port=' + str(port)
         ]
+        if RSTUDIO_RSESSION_ARGS:
+            cmd.extend(shlex.split(RSTUDIO_RSESSION_ARGS))
+        return cmd
 
     return {
         'command': _get_cmd,
         'environment': _get_env,
         'launcher_entry': {
-            'title': 'RStudio',
+            'title': 'RStudio Session',
             'icon_path': get_icon_path()
         }
     }

setup.py

@@ -1,20 +1,24 @@
 import setuptools
 
 setuptools.setup(
-    name="jupyter-rsession-proxy",
-    version='1.1',
-    url="https://github.com/jupyterhub/jupyter-rsession-proxy",
-    author="Ryan Lovett & Yuvi Panda",
-    description="Jupyter extension to proxy RStudio",
+    name='jupyter-rsession-proxy',
+    version='1.2',
+    url='https://github.com/jupyterhub/jupyter-rsession-proxy',
+    author='Ryan Lovett & Yuvi Panda & Kirill Makhonin',
+    description='Jupyter extension to proxy RStudio',
     packages=setuptools.find_packages(),
-	keywords=['Jupyter'],
-	classifiers=['Framework :: Jupyter'],
+    keywords=['Jupyter'],
+    classifiers=[
+        'Framework :: Jupyter',
+        'Programming Language :: Python :: 3'
+    ],
     install_requires=[
         'jupyter-server-proxy'
     ],
     entry_points={
         'jupyter_serverproxy_servers': [
-            'rstudio = jupyter_rsession_proxy:setup_rserver'
+            'rstudio = jupyter_rsession_proxy:setup_rserver',
+            'rsession = jupyter_rsession_proxy:setup_rsession'
         ]
     },
     package_data={