Merge pull request #543 from Kitware/settings

Server settings in configuration file

CHANGELOG.md

@@ -16,6 +16,10 @@ versioning](http://semver.org).
 - Service functions ``tangelo.redirect()`` and ``tangelo.internal_redirect()``
   to allow services to redirect to other resources
 - Service function ``tangelo.file()`` to serve arbitrary files
+- Configuration file takes CherryPy configuration options to apply at startup in
+  ``server_settings`` property
+- ``tangelo.util.set_server_setting()`` can be used to update CherryPy settings
+  at runtime
 
 ### Changed
 - Documentation introduction is more focused; tutorials are more

docs/setup.rst

@@ -102,7 +102,9 @@ key              The path to the SSL key
 
 cert             The path to the SSL certificate                                     ``None`` [#https]_ [#unset]_
 
-plugins          A list of plugins to load (see :ref:`plugin-config`)                ``None`` [#plugins]_ [#unset]_
+plugins          A list of plugins to load (see :ref:`plugin-config`)                ``None`` [#plugins_config]_ [#unset]_
+
+server-settings  A dictionary of server settings to apply when Tangelo starts.       ``None`` [#plugins_config]_ [#settings]_ [#unset]_
 ================ =================================================================   =================================
 
 .. rubric:: Footnotes
@@ -124,9 +126,20 @@ plugins          A list of plugins to load (see :ref:`plugin-config`)
 .. [#unset] That is to say, the option is simply unset by default, the
     equivalent of not mentioning the option at all in a configuration file.
 
-.. [#plugins] This option can *only* appear in the configuration file; there is
+.. [#plugins_config] This option can *only* appear in the configuration file; there is
     no command line equivalent.
 
+.. [#settings] This option provides a method for specifying settings for the
+    server technology underlying Tangelo.  For instance, using
+
+    .. code-block:: yaml
+
+        server_settings:
+            server.thread_pool: 1000
+
+    would direct Tangelo's CherryPy instance to adjust the number of simultaneous
+    requests that can be processed to 1000.
+
 Administering a Tangelo Installation
 ====================================
 

tangelo/tangelo/__main__.py

@@ -111,7 +111,8 @@ class Config(object):
                "key": types.StringTypes,
                "cert": types.StringTypes,
                "root": types.StringTypes,
-               "plugins": [list]}
+               "plugins": [list],
+               "server_settings": [dict]}
 
     def __init__(self, filename):
         for option in Config.options:
@@ -478,6 +479,13 @@ def main():
                             "server.socket_host": hostname,
                             "server.socket_port": port})
 
+    # Dump in any other global configuration present in the configuration.
+    if config.server_settings:
+        tangelo.log_info("TANGELO", "User server settings:")
+        for setting, value in config.server_settings.iteritems():
+            tangelo.util.set_server_setting(setting, value)
+            tangelo.log_info("TANGELO", "\t%s -> %s" % (setting, cherrypy.config.get(setting)))
+
     # Try to drop privileges if requested, since we've bound to whatever port
     # superuser privileges were needed for already.
     if drop_privileges:

tangelo/tangelo/util.py

@@ -65,6 +65,10 @@ def error_report(code):
     return {"message": "Error code: %s (give this code to your system administrator for more information)" % (code)}
 
 
+def set_server_setting(key, value):
+    cherrypy.config.update({key: value})
+
+
 def get_free_port():
     # Bind a socket to port 0 (which directs the OS to find an unused port).
     s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

tests/tangelo-config-settings.py

@@ -0,0 +1,42 @@
+import fixture
+import json
+import nose
+import requests
+
+
+def start_tangelo():
+    """Start tangelo with a some settings."""
+    config = {"server_settings": {"server.thread_pool": 1000}}
+    return fixture.start_tangelo("-c", json.dumps(config))
+
+
+@nose.with_setup(start_tangelo, fixture.stop_tangelo)
+def test_config_settings():
+    response = requests.get(fixture.url('settings'))
+    print response
+    assert 'pool="1000"' in response
+
+
+@nose.with_setup(start_tangelo, fixture.stop_tangelo)
+def test_config_settings_change():
+    response = requests.get(fixture.url('settings', pool='500'))
+    print response
+    assert 'pool="500"' in response
+
+
+@nose.with_setup(fixture.start_tangelo, fixture.stop_tangelo)
+def test_config_no_settings():
+    response = requests.get(fixture.url('settings'))
+    print response
+    assert 'pool="None"' in response
+
+
+def test_config_wrong_type_settings():
+    config = {"server_settings": "Angosian"}
+    (_, _, stderr) = fixture.run_tangelo(
+        "-c", json.dumps(config), terminate=True)
+    stderr = "\n".join(stderr)
+
+    print stderr
+
+    assert "option server_settings must be of type dict" in stderr

tests/tangelo-config.py

@@ -8,7 +8,7 @@ def test_bad_config():
     signal = "ERROR while parsing"
 
     print "Expected: '%s' in third line of log" % (signal)
-    print "Received: %s" % (stderr[1] if len(stderr) > 1 else "")
+    print "Received: %s" % (stderr[2] if len(stderr) > 2 else "")
 
     assert len(stderr) > 1
     assert signal in stderr[2]

tests/web/settings.py

@@ -0,0 +1,10 @@
+import cherrypy
+import tangelo
+
+
+# This service reports the value of cherrypy's thread pool setting
+def run(**kwargs):
+    if kwargs.get('pool'):
+        tangelo.util.set_server_setting('server.thread_pool', int(kwargs['pool']))
+    response = 'pool="%r"' % cherrypy.config.get('server.thread_pool')
+    return response