#!/usr/bin/python
# This script takes care of two things:
#  * Generate lighttpd configuration that puts access logs for each subdomain
#    into a separate file.
#  * Generate awstats configuration files to parse each of these.
#  * Run awstats to process all current logfiles or
#  * When --after-logrotate is given, run awstats to process the just rotated
#    logfiles.
# For the last part, it is assumed that logrotate is configured with dateext,
# without olddir and, until http://bugs.gentoo.org/106651 is fixed, with
# delaycompress.

import os, sys, datetime, subprocess

root_dir = '/data/www'
htdocs_dir = 'htdocs'
logs_dir = 'logs'
lighttpd_conf_file = '/etc/lighttpd/logging.conf'
# The directory with awstats configuration files
awstats_dir = '/etc/awstats'
# The template for each awstats configuration file. %s is replaced with the
# full domain name the configuration is for
awstats_config_file = 'awstats.%s.conf'
# Let each awstats config file include this file
awstats_common_file = os.path.join(awstats_dir, 'common.conf')
# Filename for the log files
log_file = 'access.log'
# Directory for domains we didn't find
other_dir = 'other'
awstats = '/usr/lib/cgi-bin/awstats.pl'
# Use sudo to run awstats as this user
awstats_user = 'www-data'
# The dateformat option as used by logrotate. This is the default.
dateformat = '-%Y%m%d'
# Lighttpd restart command
reload_lighttpd = 'invoke-rc.d lighttpd reload'

header = """
# This config file was autogenerated by the %s script. Do not change it
# directly, since it will be periodically regenerated.

""" % sys.argv[0]

lighttpd_conf = header
domains = {}

for d in os.listdir(root_dir):
  domain_htdocs_dir = os.path.join(root_dir, d, htdocs_dir)
  # Require a dot in the domain name to filter out stuff like "template" or
  # "php5-libs" and require the htdocs directory to exist.
  if not '.' in d or not os.path.isdir(domain_htdocs_dir):
    continue

  print "%s" % d

  # Make a dictionary of subdomains, containing a list of all aliases.
  # Iterate all subdomains by looking into the htdocs directory.
  subdomains = {}
  def add_subdomain(sub, alias=None):
      if (not sub in subdomains): subdomains[sub] = []
      if alias: subdomains[sub].append(alias)

  for dir in os.listdir(domain_htdocs_dir):
    subdomain_htdocs_dir = os.path.join(domain_htdocs_dir, dir)
    # Skip non-directories
    if not os.path.isdir(subdomain_htdocs_dir):
      continue

    # If the htdocs dir is a link, resolve it (only once!)
    if os.path.islink(subdomain_htdocs_dir):
      # Resolve the link to a full path
      target = os.readlink(subdomain_htdocs_dir)
      target = os.path.join(domain_htdocs_dir, target)
      # Only resolve links that point within the same domain
      if os.path.dirname(target) == domain_htdocs_dir:
        target = os.path.basename(target)
        print "\t\%s -> %s" % (dir, target)

        add_subdomain(target, dir)
        continue
    # If we get here, there was no resolvable link
    add_subdomain(dir, dir)

  domains[d] = subdomains

  # Generate the lighttpd config file part for this domain
  other_logfile = os.path.join(root_dir, d, logs_dir, other_dir, log_file)
  lighttpd_conf += '$HTTP["host"] =~ ".%s$" {\n' % d
  lighttpd_conf += '\t# Fallback logfile, in case none if the below conditionals match.\n'
  lighttpd_conf += '\t# This can happen when a domain was added, but the %s script\n' % sys.argv[0]
  lighttpd_conf += '\t# has not run yet\n'
  lighttpd_conf += '\taccesslog.filename = "%s"\n' % other_logfile

  # Make sure the directory exists
  if not os.path.isdir(os.path.dirname(other_logfile)):
    os.makedirs(os.path.dirname(other_logfile))

  for (s, aliases) in subdomains.items():
    print "\t%s" % s

    full_domain = "%s.%s" % (s, d)
    subdomain_logfile = os.path.join(root_dir, d, logs_dir, s, log_file)

    # Generate the lighttpd config file part for this subdomain
    print "\t\tGenerating lighttpd configuration"
    if aliases != [s]:
      # Don't use a regex if we don't need to. I think this should slightly
      # speed up lighttpd.
      aliases_regex = '|'.join(aliases)
      lighttpd_conf += '\t$HTTP["host"] =~ "^(%s).%s$" {\n' % (aliases_regex, d)
    else:
      lighttpd_conf += '\t$HTTP["host"] == "%s.%s" {\n' % (s, d)
    lighttpd_conf += '\t\taccesslog.filename = "%s"\n' % subdomain_logfile
    lighttpd_conf += '\t}\n'

    # Only generate awstats configuration for real paths, not symlinks
    awstats_conf = header
    awstats_conf += 'LogFile="%s"\n' % subdomain_logfile
    awstats_conf += 'SiteDomain="%s.%s"\n' % (s, d)
    awstats_conf += 'HostAliases="%s"\n' % ' '.join(["%s.%s" % (s, d) for s in aliases])
    awstats_conf += 'Include "%s"\n' % awstats_common_file

    # Write out the awstats config file
    subdomain_awstats_file = os.path.join(awstats_dir, awstats_config_file % full_domain)
    print "\t\tWriting %s" % subdomain_awstats_file
    f = open(subdomain_awstats_file , 'w')
    f.write(awstats_conf)

    # Make sure the directory exists
    if not os.path.isdir(os.path.dirname(subdomain_logfile)):
      os.makedirs(os.path.dirname(subdomain_logfile))

  lighttpd_conf += '}\n'

# Write out the lighttpd configuration. Check if it has changed first, to
# prevent useless lighttpd reloads.
f = open(lighttpd_conf_file, 'r+')
if lighttpd_conf != f.read():
  print "Writing %s" % lighttpd_conf_file
  f.seek(0)
  f.truncate()
  f.write(lighttpd_conf)

  # Reload lighttpd configuration
  print "Reloading lighttpd: %s" % reload_lighttpd
  ret = subprocess.call(reload_lighttpd, shell=True)

  if ret != 0:
    print >> sys.stderr, "Reloading lighttpd failed. Logging.conf was:"
    print >> sys.stderr, lighttpd_conf

f.close()

# Now, run awstats to parse log files.

if len(sys.argv) > 1 and sys.argv[1] == '--after-logrotate':
  # Logs have just been rotated, so update "todays" log. We make a guess at
  # logrotate's date extension (which shouldn't be a guess, unless logrotate's
  # dateformat was modified).
  dateext = datetime.date.today().strftime(dateformat)
else:
  dateext = ''

for (d, subdomains) in domains.items():
  for (s, aliases) in subdomains.items():
    subdomain_logfile = os.path.join(root_dir, d, logs_dir, s, log_file + dateext)

    # Call awstats. We explicitly pass in a LogFile, in case --after-logrotate
    # is given. The config parameter points to the middle part of the
    # configuration file name, awstats adds the root dir and awstats.%s.conf
    # part. We check if the file exists, since rotation might not have been
    # happened (when the file was empty, for example)
    if os.path.exists(subdomain_logfile):
      subprocess.call([ 'sudo'
                      , '-u', awstats_user
                      , awstats
                      , '-config=%s.%s' % (s, d)
                      , '-update'
                      , '-LogFile=%s' % subdomain_logfile
                      ])
    
# vim: set sw=2 sts=2 expandtab autoindent: