handle lack of color/emoji support

.tests/DockerfileUbuntu

@@ -1,4 +1,6 @@
 FROM ubuntu:bionic as base
+ENV LC_ALL=C.UTF-8
+ENV LANG=C.UTF-8
 RUN apt-get update && apt-get install -y \
     git \
     curl \
@@ -10,7 +12,8 @@ ENV PATH="$PATH:$HOME/.poetry/bin"
 FROM base
 WORKDIR ./hyperglass
 ENV python=python3
-RUN ln -s $(which python3) /usr/bin/python \
+RUN bash -c 'BASH_ENV=/etc/profile exec bash' \
+    && ln -s $(which python3) /usr/bin/python \
     && python --version \
     && $HOME/.poetry/bin/poetry install --no-ansi \
     && $HOME/.poetry/bin/poetry run hyperglass setup -d

hyperglass/cli/commands.py

@@ -2,6 +2,7 @@
 
 # Standard Library
 import os
+import sys
 from pathlib import Path
 
 # Third Party
@@ -17,10 +18,13 @@ from hyperglass.cli.formatting import HelpColorsGroup, HelpColorsCommand, random
 # Define working directory
 WORKING_DIR = Path(__file__).parent
 
+supports_color = "utf" in sys.getfilesystemencoding().lower()
+
 
 @group(
     cls=HelpColorsGroup,
     help=CLI_HELP,
+    context_settings={"color": supports_color},
     help_headers_color=LABEL,
     help_options_custom_colors=random_colors("build-ui", "start", "secret", "setup"),
 )
@@ -29,7 +33,9 @@ def hg():
     pass
 
 
-@hg.command("build-ui", help=cmd_help(E.BUTTERFLY, "Create a new UI build"))
+@hg.command(
+    "build-ui", help=cmd_help(E.BUTTERFLY, "Create a new UI build", supports_color)
+)
 def build_frontend():
     """Create a new UI build.
 
@@ -41,7 +47,7 @@ def build_frontend():
 
 @hg.command(
     "start",
-    help=cmd_help(E.ROCKET, "Start web server"),
+    help=cmd_help(E.ROCKET, "Start web server", supports_color),
     cls=HelpColorsCommand,
     help_options_custom_colors=random_colors("-b"),
 )
@@ -65,7 +71,7 @@ def start(build):
 
 @hg.command(
     "secret",
-    help=cmd_help(E.LOCK, "Generate agent secret"),
+    help=cmd_help(E.LOCK, "Generate agent secret", supports_color),
     cls=HelpColorsCommand,
     help_options_custom_colors=random_colors("-l"),
 )
@@ -86,7 +92,7 @@ def generate_secret(length):
 
 @hg.command(
     "setup",
-    help=cmd_help(E.TOOLBOX, "Run the setup wizard"),
+    help=cmd_help(E.TOOLBOX, "Run the setup wizard", supports_color),
     cls=HelpColorsCommand,
     help_options_custom_colors=random_colors("-d"),
 )

hyperglass/cli/echo.py

@@ -10,9 +10,13 @@ from hyperglass.cli.static import CMD_HELP, Message
 from hyperglass.cli.exceptions import CliError
 
 
-def cmd_help(emoji="", help_text=""):
+def cmd_help(emoji="", help_text="", supports_color=False):
     """Print formatted command help."""
-    return emoji + style(help_text, **CMD_HELP)
+    if supports_color:
+        help_str = emoji + style(help_text, **CMD_HELP)
+    else:
+        help_str = help_text
+    return help_str
 
 
 def _base_formatter(state, text, callback, **kwargs):