visualisation/visualisation.py

#! /usr/bin/python

#  Copyright 2015 Linaro Limited
#
#  This program is free software; you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation; either version 2 of the License, or
#  (at your option) any later version.
#
#  This program 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 General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program; if not, write to the Free Software
#  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
#  MA 02110-1301, USA.
#
#  Visualisation module for VLANd. Fork a trivial webserver
#  implementation on an extra, and generate a simple set of pages and
#  graphics on demand.
#

import os, sys, logging, time, datetime, re, signal
from multiprocessing import Process
from BaseHTTPServer import BaseHTTPRequestHandler
from BaseHTTPServer import HTTPServer
import urlparse
import cStringIO

if __name__ == '__main__':
    vlandpath = os.path.abspath(os.path.normpath(os.path.dirname(sys.argv[0])))
    sys.path.insert(0, vlandpath)
    sys.path.insert(0, "%s/.." % vlandpath)

from errors import InputError
from db.db import VlanDB
from config.config import VlanConfig
from graphics import Graphics,Switch
from util import VlanUtil
class VlandHTTPServer(HTTPServer):
    """ Trivial wrapper for HTTPServer so we can include our own state. """
    def __init__(self, server_address, handler, state):
        HTTPServer.__init__(self, server_address, handler)
        self.state = state

class GraphicsCache(object):
    """ Cache for graphics state, to avoid having to recalculate every
        query too many times. """
    last_update = None
    graphics = {}

    def __init__(self):
        # Pick an epoch older than any sensible use
        self.last_update = datetime.datetime(2000, 01, 01)

class Visualisation(object):
    """ Code and config for the visualisation graphics module. """

    state = None
    p = None

    # Fork a new process for the visualisation webserver
    def __init__(self, state):
        self.state = state
        self.p = Process(target=self.visloop, args=())
        self.p.start()

    def _receive_signal(self, signum, stack):
        if signum == signal.SIGUSR1:
            self.state.db_ok = True

    # The main loop for the visualisation webserver
    def visloop(self):
        self.state.db_ok = False
        self.state.cache = GraphicsCache()

        loglevel = VlanUtil().set_logging_level(self.state.config.logging.level)

        # Should we log to stderr?
        if self.state.config.logging.filename is None:
            logging.basicConfig(level = loglevel,
                                format = '%(asctime)s %(levelname)-8s %(message)s')
        else:
            logging.basicConfig(level = loglevel,
                                format = '%(asctime)s %(levelname)-8s VIS  %(message)s',
                                datefmt = '%Y-%m-%d %H:%M:%S %Z',
                                filename = self.state.config.logging.filename,
                                filemode = 'a')
            logging.info('%s visualisation starting up', self.state.banner)

        # Wait for main process to signal to us that it's finished with any
        # database upgrades and we can open it without any problems.
        signal.signal(signal.SIGUSR1, self._receive_signal)
        while not self.state.db_ok:
            logging.info('%s visualisation waiting for db_ok signal', self.state.banner)
            time.sleep(1)
        logging.info('%s visualisation received db_ok signal', self.state.banner)

        self.state.db = VlanDB(db_name=self.state.config.database.dbname,
                               username=self.state.config.database.username,
                               readonly=True)

        server = VlandHTTPServer(('', self.state.config.visualisation.port),
                                 GetHandler, self.state)
        server.serve_forever()

    # Kill the webserver
    def shutdown(self):
        self.p.terminate()

    # Kill the webserver
    def signal_db_ok(self):
        os.kill(self.p.pid, signal.SIGUSR1)

class GetHandler(BaseHTTPRequestHandler):
    """ Methods to generate and serve the pages """

    parsed_path = None

    # Trivial top-level page. Link to images for each of the VLANs we
    # know about.
    def send_index(self):
        self.send_response(200)
        self.wfile.write('Content-type: text/html\r\n')
        self.end_headers()
        config = self.server.state.config.visualisation
        cache = self.server.state.cache
        db = self.server.state.db
        switches = db.all_switches()
        vlans = db.all_vlans()
        vlan_tags = {}

        for vlan in vlans:
            vlan_tags[vlan.vlan_id] = vlan.tag

        if cache.last_update < self.server.state.db.get_last_modified_time():
            logging.debug('Cache is out of date')
            # Fill the cache with all the information we need:
            # * the graphics themselves
            # * the data to match each graphic, so we can generate imagemap/tooltips
            cache.graphics = {}
            if len(switches) > 0:
                for vlan in vlans:
                    cache.graphics[vlan.vlan_id] = self.generate_graphic(vlan.vlan_id)
            cache.last_update = datetime.datetime.utcnow()

        page = []
        page.append('<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">')
        page.append('<html>')
        page.append('<head>')
        page.append('<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">')
        page.append('<TITLE>VLANd visualisation</TITLE>')
        page.append('<link rel="stylesheet" type="text/css" href="style.css">')
        if config.refresh and config.refresh > 0:
            page.append('<meta http-equiv="refresh" content="%d">' % config.refresh)
        page.append('</HEAD>')
        page.append('<body>')

        # Generate left-hand menu with links to each VLAN diagram
        page.append('<div class="menu">')
        if len(switches) > 0:
            page.append('<h2>Menu</h2>')
            page.append('<p>VLANs: %d</p>' % len(vlans))
            page.append('<ul>')
            for vlan in vlans:
                page.append('<li><a href="./#vlan%d">VLAN ID %d, Tag %d<br>(%s)</a>' % (vlan.vlan_id, vlan.vlan_id, vlan.tag, vlan.name))
            page.append('</ul>')
        page.append('<div class="date"><p>Current time: %s</p>' % datetime.datetime.utcnow().strftime("%Y-%m-%d %H:%M:%S UTC"))
        page.append('<p>version %s</p>' % self.server.state.version)
        page.append('</div>')
        page.append('</div>')

        # Now the main content area with the graphics
        page.append('<div class="content">')
        page.append('<h1>VLANd visualisation</h1>')

        # Bail early if we have nothing to show!
        if len(switches) == 0:
            page.append('<p>No switches found in the database, nothing to show...</p>')
            page.append('</div>')
            page.append('</body>')
            self.wfile.write('\r\n'.join(page))
            return

        # Trivial javascript helpers for tooltip control
        page.append('<SCRIPT LANGUAGE="javascript">')
        page.append('function popup(v,p) {')
        page.append('a=v.toString();')
        page.append('b=p.toString();')
        page.append('id="port".concat("",a).concat(".",b);')
        page.append('document.getElementById(id).style.visibility="visible";')
        page.append('}')
        page.append('function popdown(v,p) {')
        page.append('a=v.toString();')
        page.append('b=p.toString();')
        page.append('id="port".concat("",a).concat(".",b);')
        page.append('document.getElementById(id).style.visibility="hidden";')
        page.append('}')
        page.append('</SCRIPT>')

        # For each VLAN, add a graphic
        for vlan in vlans:
            this_image = cache.graphics[vlan.vlan_id]
            page.append('<a name="vlan%d"></a>' % vlan.vlan_id)
            page.append('<h3>VLAN ID %d, Tag %d, name %s</h3>' % (vlan.vlan_id, vlan.tag, vlan.name))

            # Link to an image we generate from our data
            page.append('<p><img src="images/vlan/%d.png" ' % vlan.vlan_id)
            page.append('width="%d" height="%d" ' % ( this_image['image']['width'], this_image['image']['height']))
            page.append('alt="VLAN %d diagram" usemap="#MAPVLAN%d">' % (vlan.vlan_id,vlan.vlan_id))

            # Generate an imagemap describing all the ports, with
            # javascript hooks to pop up/down a tooltip box based on
            # later data.
            page.append('<map name="MAPVLAN%d">' % vlan.vlan_id)
            for switch in this_image['ports'].keys():
                for portnum in this_image['ports'][switch].keys():
                    this_port = this_image['ports'][switch][portnum]
                    port = this_port['db']
                    ((ulx,uly),(lrx,lry),upper) = this_port['location']
                    page.append('<area shape="rect" ')
                    page.append('coords="%d,%d,%d,%d" ' % (ulx,uly,lrx,lry))
                    page.append('onMouseOver="popup(%d,%d)" onMouseOut="popdown(%d,%d)">' % (vlan.vlan_id, port.port_id, vlan.vlan_id, port.port_id))
            page.append('</map></p>')
            page.append('<hr>')
        page.append('</div>') # End of normal content, all the VLAN graphics shown

        # Now generate the tooltip boxes for the ports. Each is
        # fully-formed but invisible, ready for our javascript helper
        # to pop visible on demand.
        for vlan in vlans:
            this_image = cache.graphics[vlan.vlan_id]
            for switch in this_image['ports'].keys():
                for portnum in this_image['ports'][switch].keys():
                    this_port = this_image['ports'][switch][portnum]
                    port = this_port['db']
                    page.append('<div class="port" id="port%d.%d">' % (vlan.vlan_id, port.port_id))
                    page.append('Port ID: %d    Port number: %d<br>' % (port.port_id, port.number))
                    if port.is_locked:
                        page.append('Locked<br>')
                    if port.is_trunk:
                        page.append('Trunk')
                        if port.trunk_id != -1:
                            page.append(' (Trunk ID %d)' % port.trunk_id)
                        page.append('<br>')
                    else:
                        page.append('Current VLAN ID: %d (Tag %d)<br>' % (port.current_vlan_id, vlan_tags[port.current_vlan_id]))
                        page.append('Base VLAN ID: %d (Tag %d)<br>' % (port.base_vlan_id, vlan_tags[port.base_vlan_id]))
                    page.append('</div>')

        page.append('</body>')
        self.wfile.write('\r\n'.join(page))

    # Simple-ish style sheet
    def send_style(self):
        self.send_response(200)
        self.wfile.write('Content-type: text/css\r\n')
        self.end_headers()
        cache = self.server.state.cache
        page = []
        page.append('body {')
        page.append('    background: white;')
        page.append('    color: black;')
        page.append('    font-size: 12pt;')
        page.append('}')
        page.append('')
        page.append('.menu {')
        page.append('	 position:fixed;')
        page.append('	 float:left;')
        page.append('    font-family: arial, Helvetica, sans-serif;')
        page.append('	 width:20%;')
        page.append('	 height:100%;')
        page.append('    font-size: 10pt;')
        page.append('    padding-top: 10px;')
        page.append('}')
        page.append('')
        page.append('.content {')
        page.append('	 position:relative;')
        page.append('    padding-top: 10px;')
        page.append('	 width: 80%;')
        page.append('	 max-width:80%;')
        page.append('	 margin-left: 21%;')
        page.append('    margin-top: 50px;')
        page.append('	 height:100%;')
        page.append('}')
        page.append('')
        page.append('h1,h2,h3 {')
        page.append('    font-family: arial, Helvetica, sans-serif;')
        page.append('    padding-right:3pt;')
        page.append('    padding-top:2pt;')
        page.append('    padding-bottom:2pt;')
        page.append('    margin-top:8pt;')
        page.append('    margin-bottom:8pt;')
        page.append('    border-style:none;')
        page.append('    border-width:thin;')
        page.append('}')
        page.append('A:link { text-decoration: none; }')
        page.append('A:visited { text-decoration: none}')
        page.append('h1 { font-size: 18pt; }')
        page.append('h2 { font-size: 14pt; }')
        page.append('h3 { font-size: 12pt; }')
        page.append('dl,ul { margin-top: 1pt; text-indent: 0 }')
        page.append('ol { margin-top: 1pt; text-indent: 0 }')
        page.append('div.date { font-size: 8pt; }')
        page.append('div.sig { font-size: 8pt; }')
        page.append('div.port {')
        page.append('    display: block;')
        page.append('    position: fixed;')
        page.append('    left: 0px;')
        page.append('    bottom: 0px;')
        page.append('    z-index: 99;')
        page.append('    background: #FFFF00;')
        page.append('    border-style: solid;')
        page.append('    border-width: 3pt;')
        page.append('    border-color: #3B3B3B;')
        page.append('    margin: 1;')
        page.append('    padding: 5px;')
        page.append('    font-size: 10pt;')
        page.append('    font-family: Courier,monotype;')
        page.append('    visibility: hidden;')
        page.append('}')
        self.wfile.write('\r\n'.join(page))

    # Generate a PNG showing the layout of switches/port/trunks for a
    # specific VLAN
    def send_graphic(self):
        vlan_id = 0
        vlan_re = re.compile(r'^/images/vlan/(\d+).png$')
        match = vlan_re.match(self.parsed_path.path)
        if match:
            vlan_id = int(match.group(1))
        cache = self.server.state.cache

        # Do we have a graphic for this VLAN ID?
        if not vlan_id in cache.graphics.keys():
            logging.debug('asked for vlan_id %s', vlan_id)
            logging.debug(cache.graphics.keys())
            self.send_response(404)
            self.wfile.write('Content-type: text/plain\r\n')
            self.end_headers()
            self.wfile.write('404 Not Found\r\n')
            self.wfile.write('%s' % self.parsed_path.path)
            logging.error('VLAN graphic not found - asked for %s', self.parsed_path.path)
            return

        # Yes - just send it from the cache
        self.send_response(200)
        self.wfile.write('Content-type: image/png\r\n')
        self.end_headers()
        self.wfile.write(cache.graphics[vlan_id]['image']['png'].getvalue())
        return

    # Generate a PNG showing the layout of switches/port/trunks for a
    # specific VLAN, and return that PNG along with geometry details
    def generate_graphic(self, vlan_id):
        db = self.server.state.db
        vlan = db.get_vlan_by_id(vlan_id)
        # We've been asked for a VLAN that doesn't exist
        if vlan is None:
            return None

        data = {}
        data['image'] = {}
        data['ports'] = {}

        gim = Graphics()

        # Pick fonts. TODO: Make these configurable?
        gim.set_font(['/usr/share/fonts/truetype/inconsolata/Inconsolata.otf',
                      '/usr/share/fonts/truetype/freefont/FreeMono.ttf'])
        try:
            gim.font
        # If we can't get the font we need, fail
        except NameError:
            self.send_response(500)
            self.wfile.write('Content-type: text/plain\r\n')
            self.end_headers()
            self.wfile.write('500 Internal Server Error\r\n')
            logging.error('Unable to generate graphic, no fonts found - asked for %s',
                          self.parsed_path.path)
            return

        switch = {}
        size_x = {}
        size_y = {}

        switches = db.all_switches()

        # Need to set gaps big enough for the number of trunks, at least.
        trunks = db.all_trunks()
        y_gap = max(20, 15 * len(trunks))
        x_gap = max(20, 15 * len(trunks))

        x = 0
        y = y_gap

        # Work out how much space we need for the switches
        for i in range(0, len(switches)):
            ports = db.get_ports_by_switch(switches[i].switch_id)
            switch[i] = Switch(gim, len(ports), switches[i].name)
            (size_x[i], size_y[i]) = switch[i].get_dimensions()
            x = max(x, size_x[i])
            y += size_y[i] + y_gap

        # Add space for the legend and the label
        label = "VLAN %d - %s" % (vlan.tag, vlan.name)
        (legend_width, legend_height) = gim.get_legend_dimensions()
        (label_width, label_height) = gim.get_label_size(label, gim.label_font_size)
        x = max(x, legend_width + 2*x_gap + label_width)
        x = x_gap + x + x_gap
        y = y + max(legend_height + y_gap, label_height)

        # Create a canvas of the right size
        gim.create_canvas(x, y)

        # Draw the switches and ports in it
        curr_y = y_gap
        for i in range(0, len(switches)):
            switch[i].draw_switch(gim, x_gap, curr_y)
            ports = db.get_ports_by_switch(switches[i].switch_id)
            data['ports'][i] = {}
            for port_id in ports:
                port = db.get_port_by_id(port_id)
                port_location = switch[i].get_port_location(port.number)
                data['ports'][i][port.number] = {}
                data['ports'][i][port.number]['db'] = port
                data['ports'][i][port.number]['location'] = port_location
                if port.is_locked:
                    switch[i].draw_port(gim, port.number, 'locked')
                elif port.is_trunk:
                    switch[i].draw_port(gim, port.number, 'trunk')
                elif port.current_vlan_id == int(vlan_id):
                    switch[i].draw_port(gim, port.number, 'VLAN')
                else:
                    switch[i].draw_port(gim, port.number, 'normal')
            curr_y += size_y[i] + y_gap

        # Now add the trunks
        for i in range(0, len(trunks)):
            ports = db.get_ports_by_trunk(trunks[i].trunk_id)
            port1 = db.get_port_by_id(ports[0])
            port2 = db.get_port_by_id(ports[1])
            for s in range(0, len(switches)):
                if switches[s].switch_id == port1.switch_id:
                    switch1 = s
                if switches[s].switch_id == port2.switch_id:
                    switch2 = s
            gim.draw_trunk(i,
                           switch[switch1].get_port_location(port1.number),
                           switch[switch2].get_port_location(port2.number),
                           gim.port_pallette['trunk']['trace'])

        # And the legend and label
        gim.draw_legend(x_gap, curr_y)
        gim.draw_label(x - label_width - 2*x_gap, curr_y, label, int(x_gap / 2))

        # All done - push the image file into the cache for this vlan
        data['image']['png'] = cStringIO.StringIO()
        gim.im.writePng(data['image']['png'])
        data['image']['width'] = x
        data['image']['height'] = y
        return data

    # Implement an HTTP GET handler for the HTTPServer instance
    def do_GET(self):
        # Compare the URL path to any of the names we recognise and
        # call the right generator function if we get a match
        self.parsed_path = urlparse.urlparse(self.path)
        for url in self.functionMap:
            match = re.match(url['re'], self.parsed_path.path)
            if match:
                return url['fn'](self)

        # Fall-through for any files we don't recognise
        self.send_response(404)
        self.wfile.write('Content-type: text/plain\r\n')
        self.end_headers()
        self.wfile.write('404 Not Found')
        self.wfile.write('%s' % self.parsed_path.path)
        logging.error('File not supported - asked for %s', self.parsed_path.path)
        return

    # Override the BaseHTTPRequestHandler log_message() method so we
    # can log requests properly
    def log_message(self, fmt, *args):
        """Log an arbitrary message. """
        logging.info('%s %s', self.client_address[0], fmt%args)

    functionMap = (
        {'re': r'^/$', 'fn': send_index},
        {'re': r'^/style.css$', 'fn': send_style},
        {'re': r'^/images/vlan/(\d+).png$', 'fn': send_graphic}
    )