Update cli.py to support custom loggers (#1906)HEADmaster

* Update cli.py to support custom loggers

Allows a config.py file (via rq worker --config) to support things like this for logfmt logging:

DICT_CONFIG = {
        "version": 1,
        "formatters": {"logfmt": {
            "()": "logfmter.Logfmter",
            "keys": ["level","when","pid"],
            "mapping": {"level":"levelname","when":"asctime","pid":"process"},
            "datefmt": "%Y-%m-%dT%H:%M:%S%z"
            }},
        "handlers": {"console": {"class": "logging.StreamHandler","formatter": "logfmt" }},
        "loggers": {
            "root": {"handlers":["console"], "level": "INFO"},
            "rq":   {"handlers":["console"], "level": "INFO", "propagate": False},
            }
        }

* added simple test and documentation for DICT_CONFIG

* further attempt to get testing right for dictConfig

* move import to correct location

* fix

* remove meaningless options.get() usage

* linting checks and added missing test config file

1 files changed, 27 insertions, 0 deletions

diff --git a/docs/docs/workers.md b/docs/docs/workers.md
index 71d2ba7..8c6d663 100644
--- a/docs/docs/workers.md
+++ b/docs/docs/workers.md
@@ -276,6 +276,33 @@ SENTRY_DSN = 'sync+http://public:secret@example.com/1'
 
 # If you want custom worker name
 # NAME = 'worker-1024'
+
+# If you want to use a dictConfig <https://docs.python.org/3/library/logging.config.html#logging-config-dictschema>
+# for more complex/consistent logging requirements.
+DICT_CONFIG = {
+    'version': 1,
+    'disable_existing_loggers': False,
+    'formatters': {
+        'standard': {
+            'format': '%(asctime)s [%(levelname)s] %(name)s: %(message)s'
+        },
+    },
+    'handlers': {
+        'default': {
+            'level': 'INFO',
+            'formatter': 'standard',
+            'class': 'logging.StreamHandler',
+            'stream': 'ext://sys.stderr',  # Default is stderr
+        },
+    },
+    'loggers': {
+        'root': {  # root logger
+            'handlers': ['default'],
+            'level': 'INFO',
+            'propagate': False
+        },
+    }
+}
 ```
 
 The example above shows all the options that are currently supported.