cli: add a -n/--no-colors option

Bug: T212783
Change-Id: Ie243177f29018f95f59f0261b6e2b9258b56c607

TODO.rst

@@ -23,7 +23,6 @@ Small improvements
 * global: allow to log the whole output to a specific file, to allow multiple people follow the progress.
 * global: allow to randomize the list hosts before execution `T164587`_.
 * CLI: improve the dry-run mode to show what would have been done.
-* CLI: add a ``--color`` or a ``--no-color`` option to manage the output color.
 * CLI: read commands from a file, one per line.
 * CLI: add ``--limit`` to randomly select N hosts within a broader selection.
 * puppetdb backend: improve globbing support, check if fnmatch could be used without conflicting with ClusterShell

cumin/cli.py

@@ -108,6 +108,7 @@ def get_parser():
                         help='Specify a different output format. [default: None]')
     parser.add_argument('-i', '--interactive', action='store_true',
                         help='Drop into a Python shell with the results. [default: False]')
+    parser.add_argument('-n', '--no-colors', action='store_true', help='Disable colored output. [default: False]')
     parser.add_argument('--force', action='store_true',
                         help=('USE WITH CAUTION! Force the execution without confirmation of the affected hosts. '
                               '[default: False]'))
@@ -183,6 +184,8 @@ def parse_args(argv):
     """
     parser = get_parser()
     parsed_args = parser.parse_args(argv)
+    if parsed_args.no_colors:
+        Colored.disabled = True
 
     # Validation and default values
     num_commands = len(parsed_args.commands)

cumin/tests/unit/test_cli.py

@@ -7,6 +7,7 @@
 import pytest
 
 from cumin import cli, CuminError, LOGGING_TRACE_LEVEL_NUMBER, nodeset, transports
+from cumin.color import Colored
 
 
 # Environment variables
@@ -62,6 +63,14 @@ def test_parse_args_no_mode():
         cli.parse_args(_ARGV[:index] + _ARGV[index + 1:])
 
 
+def test_parse_args_no_colors():
+    """If -n/--no-colors is specified, the colors should be globally disabled."""
+    assert not Colored.disabled
+    cli.parse_args(_ARGV[:2] + ['-n'] + _ARGV[3:])
+    assert Colored.disabled
+    Colored.disabled = False  # Reset it
+
+
 def test_target_batch_size():
     """Calling target_batch_size() should properly parse integer values."""
     assert cli.target_batch_size('1') == {'value': 1, 'ratio': None}