added capability to take JSON as log's config

docs/source/settings.rst

@@ -264,6 +264,16 @@ The log config file to use.
 Gunicorn uses the standard Python logging module's Configuration
 file format.
 
+.. _logconfig-json:
+
+logiconfig_json
+~~~~~~~~~
+
+* ``--log-config-json FILE``
+* ``None``
+
+The log config file written in JSON.
+
 .. _logconfig-dict:
 
 logconfig_dict
@@ -274,8 +284,9 @@ logconfig_dict
 
 The log config dictionary to use, using the standard Python
 logging module's dictionary configuration format. This option
-takes precedence over the :ref:`logconfig` option, which uses the
+takes precedence over the :ref:`logconfig` and :ref:`logConfigJson` options, which uses the
-older file configuration format.
+older file configuration format and JSON respectively.
+
 
 Format: https://docs.python.org/3/library/logging.config.html#logging.config.dictConfig
 
@@ -1173,11 +1184,11 @@ libraries may be installed using setuptools' ``extra_require`` feature.
 A string referring to one of the following bundled classes:
 
 * ``sync``
-* ``eventlet`` - Requires eventlet >= 0.9.7 (or install it via 
+* ``eventlet`` - Requires eventlet >= 0.9.7 (or install it via
   ``pip install gunicorn[eventlet]``)
-* ``gevent``   - Requires gevent >= 0.13 (or install it via 
+* ``gevent``   - Requires gevent >= 0.13 (or install it via
   ``pip install gunicorn[gevent]``)
-* ``tornado``  - Requires tornado >= 0.2 (or install it via 
+* ``tornado``  - Requires tornado >= 0.2 (or install it via
   ``pip install gunicorn[tornado]``)
 * ``gthread``  - Python 2 requires the futures package to be installed
   (or install it via ``pip install gunicorn[gthread]``)

gunicorn/config.py

@@ -627,11 +627,11 @@ class WorkerClass(Setting):
         A string referring to one of the following bundled classes:
 
         * ``sync``
-        * ``eventlet`` - Requires eventlet >= 0.9.7 (or install it via 
+        * ``eventlet`` - Requires eventlet >= 0.9.7 (or install it via
           ``pip install gunicorn[eventlet]``)
-        * ``gevent``   - Requires gevent >= 0.13 (or install it via 
+        * ``gevent``   - Requires gevent >= 0.13 (or install it via
           ``pip install gunicorn[gevent]``)
-        * ``tornado``  - Requires tornado >= 0.2 (or install it via 
+        * ``tornado``  - Requires tornado >= 0.2 (or install it via
           ``pip install gunicorn[tornado]``)
         * ``gthread``  - Python 2 requires the futures package to be installed
           (or install it via ``pip install gunicorn[gthread]``)
@@ -668,7 +668,7 @@ class WorkerThreads(Setting):
         If it is not defined, the default is ``1``.
 
         This setting only affects the Gthread worker type.
-        
+
         .. note::
            If you try to use the ``sync`` worker type and set the ``threads``
            setting to more than 1, the ``gthread`` worker type will be used
@@ -1368,8 +1368,8 @@ class LogConfigDict(Setting):
     desc = """\
     The log config dictionary to use, using the standard Python
     logging module's dictionary configuration format. This option
-    takes precedence over the :ref:`logconfig` option, which uses the
+    takes precedence over the :ref:`logconfig` and :ref:`logConfigJson` options, which uses the
-    older file configuration format.
+    older file configuration format and JSON respectively.
 
     Format: https://docs.python.org/3/library/logging.config.html#logging.config.dictConfig
 
@@ -1377,6 +1377,22 @@ class LogConfigDict(Setting):
     """
 
 
+class LogConfigJson(Setting):
+    name = "logconfig_json"
+    section = "Logging"
+    cli = ["--log-config-json"]
+    meta = "FILE"
+    validator = validate_string
+    default = None
+    desc = """\
+    The log config JSON reads config from a JSON file
+
+    Format: https://docs.python.org/3/library/logging.config.html#logging.config.dictConfig
+
+    .. versionadded:: 19.9
+    """
+
+
 class SyslogTo(Setting):
     name = "syslog_addr"
     section = "Logging"

gunicorn/glogging.py

@@ -5,6 +5,7 @@
 
 import base64
 import binascii
+import json
 import time
 import logging
 logging.Logger.manager.emittedNoHandlerWarning = 1
@@ -238,6 +239,21 @@ class Logger(object):
                     TypeError
             ) as exc:
                 raise RuntimeError(str(exc))
+        elif cfg.logconfig_json:
+            config = CONFIG_DEFAULTS.copy()
+            if os.path.exists(cfg.logconfig_json):
+                try:
+                    config_json = json.load(open(cfg.logconfig_json))
+                    config.update(config_json)
+                    dictConfig(config)
+                except(
+                    json.JSONDecodeError,
+                    AttributeError,
+                    ImportError,
+                    ValueError,
+                    TypeError
+                ) as exc:
+                    raise RuntimeError(str(exc))
         elif cfg.logconfig:
             if os.path.exists(cfg.logconfig):
                 defaults = CONFIG_DEFAULTS.copy()
@@ -330,7 +346,7 @@ class Logger(object):
         """
 
         if not (self.cfg.accesslog or self.cfg.logconfig or
-           self.cfg.logconfig_dict or
+           self.cfg.logconfig_dict or self.cfg.logconfig_json or
            (self.cfg.syslog and not self.cfg.disable_redirect_access_to_syslog)):
             return