Add PATRONICTL_CONFIG_FILE Environment Variable
add a `PATRONICTL_CONFIG_FILE` environment variable, which allows configuring the --config-file flag from the environment.
@@ -111,7 +111,8 @@ option_insecure = click.option('-k', '--insecure', is_flag=True, help='Allow con
@click.group()
-@click.option('--config-file', '-c', help='Configuration file', default=CONFIG_FILE_PATH)
+@click.option('--config-file', '-c', help='Configuration file',
+ envvar='PATRONICTL_CONFIG_FILE', default=CONFIG_FILE_PATH)
@click.option('--dcs', '-d', help='Use this DCS', envvar='DCS')
@option_insecure
@click.pass_context
