Merge pull request #66 from pangeo-forge/logging-config

Support setting arbitrary logging config

pangeo_forge_runner/commands/base.py

@@ -7,7 +7,7 @@
 
 from pythonjsonlogger import jsonlogger
 from repo2docker import contentproviders
-from traitlets import Bool, Instance, List, Unicode
+from traitlets import Bool, Dict, Instance, List, Unicode
 from traitlets.config import Application
 
 # Common aliases we want to support in *all* commands
@@ -41,6 +41,21 @@ class BaseCommand(Application):
 
     log_level = logging.INFO
 
+    logging_config = Dict(
+        {},
+        config=True,
+        help="""
+        Logging configuration for this python application.
+
+        When set, this value is passed to logging.config.dictConfig,
+        and can be used to configure how logs *throughout the application*
+        are handled, not just for logs from this application alone.
+
+        See https://docs.python.org/3/library/logging.config.html#logging.config.dictConfig
+        for more details.
+        """,
+    )
+
     repo = Unicode(
         "",
         config=True,
@@ -199,6 +214,13 @@ def initialize(self, argv=None):
         # Load traitlets config from a config file if present
         self.load_config_file(self.config_file)
 
+        # Allow arbitrary logging config if set
+        # We do this first up so any custom logging we set up ourselves
+        # is not affected, as by default dictConfig will replace all
+        # existing config.
+        if self.logging_config:
+            logging.config.dictConfig(self.logging_config)
+
         # The application communicates with the outside world via
         # stdout, and we structure this communication via logging.
         # So let's setup the default logger to log to stdout, rather