Configure basic logging, and make it possible to log to console.

--log-to-console will output messages at INFO and above to the
command-line.  This is super-useful when running cloud-init from a
terminal, when you don't want to have to dig in a log file.

Change-Id: Ieb3db384b73441c19ef463649c94b04ffaac8026

cloudinit/logging.py

@@ -40,6 +40,7 @@ class _BlatherLoggerAdapter(logging.LoggerAdapter):
 
 # TODO(harlowja): we should remove when we no longer have to support 2.6...
 if sys.version_info[0:2] == (2, 6):  # pragma: nocover
+    from logutils.dictconfig import dictConfig
 
     class _FixedBlatherLoggerAdapter(_BlatherLoggerAdapter):
         """Ensures isEnabledFor() exists on adapters that are created."""
@@ -72,6 +73,7 @@ if sys.version_info[0:2] == (2, 6):  # pragma: nocover
             self.lock = None
 
 else:
+    from logging.config import dictConfig
     _NullHandler = logging.NullHandler
 
 
@@ -80,3 +82,32 @@ def getLogger(name=_BASE, extra=None):
     if not logger.handlers:
         logger.addHandler(_NullHandler())
     return _BlatherLoggerAdapter(logger, extra=extra)
+
+
+def configure_logging(log_to_console=False):
+    logging_config = {
+        'version': 1,
+        'disable_existing_loggers': False,
+        'formatters': {
+            'standard': {
+                'format': '%(asctime)s [%(levelname)s] %(name)s: %(message)s',
+            },
+        },
+        'handlers': {
+            'console': {
+                'level': 'INFO',
+                'class': 'logging.StreamHandler',
+                'formatter': 'standard',
+            },
+        },
+        'loggers': {
+            '': {
+                'handlers': [],
+                'level': 'DEBUG',
+                'propagate': True,
+            },
+        },
+    }
+    if log_to_console:
+        logging_config['loggers']['']['handlers'].append('console')
+    dictConfig(logging_config)

cloudinit/shell.py

@@ -6,6 +6,8 @@
 import argparse
 import sys
 
+from cloudinit import logging
+
 
 def populate_parser(parser, common, subcommands):
     """Populate an ArgumentParser with data rather than code
@@ -48,6 +50,7 @@ def main(args=sys.argv):
 
     if not hasattr(parsed, 'func'):
         parser.error('too few arguments')
+    logging.configure_logging(log_to_console=parsed.log_to_console)
     parsed.func(parsed)
     return 0
 
@@ -63,6 +66,7 @@ def unimplemented_subcommand(args):
 
 
 COMMON_ARGS = [
+    (('--log-to-console',), {'action': 'store_true', 'default': False}),
     (('--verbose', '-v'), {'action': 'count', 'default': 0}),
 ]
 

cloudinit/tests/test_shell.py

@@ -46,3 +46,18 @@ class TestMain(TestCase):
         self.assertRaises(SystemExit, shell.main, args=['cloud-init'])
         self.assertIn('cloud-init: error: too few arguments',
                       stderr.getvalue())
+
+
+class TestLoggingConfiguration(TestCase):
+
+    @mock.patch('cloudinit.shell.sys.stderr', new_callable=six.StringIO)
+    def test_log_to_console(self, stderr):
+        shell.main(args=['cloud-init', '--log-to-console', 'version'])
+        shell.logging.getLogger().info('test log message')
+        self.assertIn('test log message', stderr.getvalue())
+
+    @mock.patch('cloudinit.shell.sys.stderr', new_callable=six.StringIO)
+    def test_log_to_console_not_default(self, stderr):
+        shell.main(args=['cloud-init', 'version'])
+        shell.logging.getLogger().info('test log message')
+        self.assertNotIn('test log message', stderr.getvalue())

tox.ini

@@ -22,6 +22,7 @@ install_command = pip install {opts} {packages}
 [testenv:py26]
 deps = {[testenv]deps}
     importlib
+    logutils
 
 [testenv:py27-coverage]
 commands = {envpython} {toxinidir}/tools/noproxy nosetests --with-coverage --cover-erase --cover-package=cloudinit --cover-min-percentage=90 --cover-html {posargs}