Merge branch 'issue1029' into develop

NEWS

@@ -9,6 +9,7 @@ Enhancements and new features:
 
     * Use new sensors-related APIs of Psutil 5.1.0 (issue #1018)
     => Remove Py3Sensors and Batinfo dependencies
+    * Add a "Cloud" plugin to grab stats inside the AWS EC2 API (issue #1029) 
 
 Bugs corrected:
 

docs/aoa/header.rst

@@ -11,6 +11,9 @@ Additionally, on GNU/Linux, it also shows the kernel version.
 
 In client mode, the server connection status is also displayed.
 
+If you are hosted on an AWS EC2 instance, some additional information
+can be displayed (AMI-ID, region).  
+
 **Connected**:
 
 .. image:: ../_static/connected.png

docs/man/glances.1

@@ -1,6 +1,6 @@
 .\" Man page generated from reStructuredText.
 .
-.TH "GLANCES" "1" "Feb 11, 2017" "2.8.3_DEVELOP" "Glances"
+.TH "GLANCES" "1" "Feb 12, 2017" "2.8.3_DEVELOP" "Glances"
 .SH NAME
 glances \- An eye on your system
 .

glances/main.py

@@ -103,6 +103,8 @@ Start the client browser (browser mode):\n\
                             dest='disable_alert', help='disable alert module')
         parser.add_argument('--disable-amps', action='store_true', default=False,
                             dest='disable_amps', help='disable applications monitoring process (AMP) module')
+        parser.add_argument('--disable-cloud', action='store_true', default=False,
+                            dest='disable_cloud', help='disable Cloud module')
         parser.add_argument('--disable-cpu', action='store_true', default=False,
                             dest='disable_cpu', help='disable CPU module')
         parser.add_argument('--disable-diskio', action='store_true', default=False,

glances/outputs/glances_curses.py

@@ -54,11 +54,12 @@ class _GlancesCurses(object):
         '3': {'switch': 'disable_quicklook'},
         '6': {'switch': 'meangpu'},
         '/': {'switch': 'process_short_name'},
-        'd': {'switch': 'disable_diskio'},
         'A': {'switch': 'disable_amps'},
         'b': {'switch': 'byte'},
         'B': {'switch': 'diskio_iops'},
+        'C': {'switch': 'disable_cloud'},
         'D': {'switch': 'disable_docker'},
+        'd': {'switch': 'disable_diskio'},
         'F': {'switch': 'fs_free_space'},
         'G': {'switch': 'disable_gpu'},
         'h': {'switch': 'help_tag'},
@@ -545,6 +546,7 @@ class _GlancesCurses(object):
 
         # =====================================
         # Display first line (system+ip+uptime)
+        # Optionnaly: Cloud on second line
         # =====================================
         self.__display_firstline(__stat_display)
 
@@ -628,7 +630,11 @@ class _GlancesCurses(object):
         # Space between column
         self.space_between_column = 3
         self.new_column()
-        self.display_plugin(stat_display["uptime"])
+        self.display_plugin(stat_display["uptime"],
+                            add_space=self.get_stats_display_width(stat_display["cloud"]) == 0)
+        self.init_column()
+        self.new_line()
+        self.display_plugin(stat_display["cloud"])
 
     def __display_secondline(self, stat_display, stats):
         """Display the second line in the Curses interface.
@@ -829,7 +835,8 @@ class _GlancesCurses(object):
     def display_plugin(self, plugin_stats,
                        display_optional=True,
                        display_additional=True,
-                       max_y=65535):
+                       max_y=65535,
+                       add_space=True):
         """Display the plugin_stats on the screen.
 
         If display_optional=True display the optional stats
@@ -913,6 +920,10 @@ class _GlancesCurses(object):
             self.next_column, x_max + self.space_between_column)
         self.next_line = max(self.next_line, y + self.space_between_line)
 
+        if not add_space and self.next_line > 0:
+            # Do not have empty line after
+            self.next_line -= 1
+
     def erase(self):
         """Erase the content of the screen."""
         self.term_window.erase()

glances/plugins/glances_cloud.py

@@ -0,0 +1,173 @@
+# -*- coding: utf-8 -*-
+#
+# This file is part of Glances.
+#
+# Copyright (C) 2017 Nicolargo <nicolas@nicolargo.com>
+#
+# Glances is free software; you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Glances is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+"""Cloud plugin.
+
+Supported Cloud API:
+- AWS EC2 (class ThreadAwsEc2Grabber, see bellow)
+"""
+
+try:
+    import requests
+except ImportError:
+    cloud_tag = False
+else:
+    cloud_tag = True
+
+import threading
+
+from glances.compat import iteritems
+from glances.plugins.glances_plugin import GlancesPlugin
+from glances.logger import logger
+
+
+class Plugin(GlancesPlugin):
+
+    """Glances' cloud plugin.
+
+    The goal of this plugin is to retreive additional information
+    concerning the datacenter where the host is connected.
+
+    See https://github.com/nicolargo/glances/issues/1029
+
+    stats is a dict
+    """
+
+    def __init__(self, args=None):
+        """Init the plugin."""
+        super(Plugin, self).__init__(args=args)
+
+        # We want to display the stat in the curse interface
+        self.display_curse = True
+
+        # Init the stats
+        self.reset()
+
+        # Init thread to grab AWS EC2 stats asynchroniously
+        self.aws_ec2 = ThreadAwsEc2Grabber()
+
+        # Run the thread
+        self.aws_ec2. start()
+
+    def reset(self):
+        """Reset/init the stats."""
+        self.stats = {}
+
+    def exit(self):
+        """Overwrite the exit method to close threads"""
+        self.aws_ec2.stop()
+        # Call the father class
+        super(Plugin, self).exit()
+
+    @GlancesPlugin._check_decorator
+    @GlancesPlugin._log_result_decorator
+    def update(self):
+        """Update the cloud stats.
+
+        Return the stats (dict)
+        """
+        # Reset stats
+        self.reset()
+
+        # Requests lib is needed to get stats from the Cloud API
+        if not cloud_tag:
+            return self.stats
+
+        # Update the stats
+        if self.input_method == 'local':
+            self.stats = self.aws_ec2.stats
+
+        return self.stats
+
+    def msg_curse(self, args=None):
+        """Return the string to display in the curse interface."""
+        # Init the return message
+        ret = []
+
+        if not self.stats \
+           or self.stats == {} \
+           or self.is_disable():
+            return ret
+
+        # Generate the output
+        if 'ami-id' in self.stats and 'region' in self.stats:
+            msg = 'AWS EC2'
+            ret.append(self.curse_add_line(msg, "TITLE"))
+            msg = ' instance {} ({})'.format(self.stats['ami-id'],
+                                             self.stats['region'])
+            ret.append(self.curse_add_line(msg))
+
+        # Return the message with decoration
+        logger.info(ret)
+        return ret
+
+
+class ThreadAwsEc2Grabber(threading.Thread):
+    """
+    Specific thread to grab AWS EC2 stats.
+
+    stats is a dict
+    """
+
+    # AWS EC2
+    # http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-instance-metadata.html
+    AWS_EC2_API_URL = 'http://169.254.169.254/latest/meta-data'
+    AWS_EC2_API_METADATA = {'ami-id': 'ami-id',
+                            'region': 'placement/availability-zone'}
+
+    def __init__(self):
+        """Init the class"""
+        logger.debug("cloud plugin - Create thread for AWS EC2")
+        super(ThreadAwsEc2Grabber, self).__init__()
+        # Event needed to stop properly the thread
+        self._stopper = threading.Event()
+        # The class return the stats as a dict
+        self._stats = {}
+
+    def run(self):
+        """Function called to grab stats.
+        Infinite loop, should be stopped by calling the stop() method"""
+
+        for k, v in iteritems(self.AWS_EC2_API_METADATA):
+            r_url = '{}/{}'.format(self.AWS_EC2_API_URL, v)
+            try:
+                r = requests.get(r_url)
+            except Exception as e:
+                logger.debug('Can not connect to the AWS EC2 API {}'.format(r_url, e))
+            else:
+                self._stats[k] = r
+
+    @property
+    def stats(self):
+        """Stats getter"""
+        return self._stats
+
+    @stats.setter
+    def stats(self, value):
+        """Stats setter"""
+        self._stats = value
+
+    def stop(self, timeout=None):
+        """Stop the thread"""
+        logger.debug("cloud plugin - Close thread for AWS EC2")
+        self._stopper.set()
+
+    def stopped(self):
+        """Return True is the thread is stopped"""
+        return self._stopper.isSet()