Removed the need for dummy IP prefix.

README.rst

@@ -103,8 +103,6 @@ A list of IP prefixes (<IP>/<prefix length>) is stored in a text file. IP prefix
 
 This configuration logic allows a separate process to update the list by adding or removing IP prefixes and trigger a reconfiguration of Bird in order to advertise or withdraw routes. **anycast-healthchecker** is that separate process. It monitors Anycasted services and, based on the status of the health checks, updates the list of IP prefixes.
 
-Bird does not allow the definition of a list with no elements: if that happens Bird will produce an error and refuses to start. Because of this, anycast-healthchecker makes sure that there is always an IP prefix in the list, see ``dummy_ip_prefix`` and ``dummy_ip6_prefix`` settings in `Daemon section`_.
-
 Configuring anycast-healthchecker
 ---------------------------------
 
@@ -181,8 +179,6 @@ anycast-prefixes.conf
  10.189.200.255/32
  ];
 
-anycast-healthchecker removes IP prefixes from the list for which a service check is not configured. But, the IP prefix set in ``dummy_ip_prefix`` does not need a service check configuration.
-
 This the equivalent list for IPv6 prefixes::
 
  define ACAST6_PS_ADVERTISE =
@@ -227,8 +223,6 @@ anycast-healthchecker uses the popular `INI`_ format for its configuration files
  bird6_variable = ACAST6_PS_ADVERTISE
  bird_reconfigure_cmd = sudo /usr/sbin/birdc configure
  bird6_reconfigure_cmd = sudo /usr/sbin/birdc6 configure
- dummy_ip_prefix = 10.189.200.255/32
- dummy_ip6_prefix = 2001:db8::1/128
  bird_keep_changes = false
  bird6_keep_changes = false
  bird_changes_counter = 128
@@ -302,14 +296,6 @@ Command to trigger a reconfiguration of IPv4 Bird daemon
 
 Command to trigger a reconfiguration of IPv6 Bird daemon
 
-* **dummy_ip_prefix** Defaults to **10.189.200.255/32**
-
-An IP prefix in the form <IP>/<prefix length> which will be always available in the list defined by ``bird_variable`` to avoid having an empty list. The ``dummy_ip_prefix`` **must not** be used by any service or assigned to the interface set with ``interface`` or configured anywhere on the network as anycast-healthchecker **does not** perform any checks for it.
-
-* **dummy_ip6_prefix** Defaults to **2001:db8::1/128**
-
-An IPv6 prefix in the form <IPv6>/<prefix length> which will be always available in the list defined by ``bird6_variable`` to avoid having an empty list. The ``dummy_ip6_prefix`` **must not** be used by any service or assigned to the interface set with ``interface`` or configured anywhere on the network as anycast-healthchecker **does not** perform any checks for it.
-
 * **bird_keep_changes** Defaults to **false**
 
 Keep a history of changes for ``bird_conf`` file by copying it to a directory. During the startup of anycast-healthchecker a directory with the name ``history`` is created under the directory where ``bird_conf`` file resides. The daemon has to have sufficient privileges to create that directory.

anycast-healthchecker.conf

@@ -11,8 +11,6 @@ bird_variable = ACAST_PS_ADVERTISE
 bird6_variable = ACAST6_PS_ADVERTISE
 bird_reconfigure_cmd = sudo /usr/sbin/birdc configure
 bird6_reconfigure_cmd = sudo /usr/sbin/birdc6 configure
-dummy_ip_prefix = 10.189.200.255/32
-dummy_ip6_prefix = 2001:db8::1/128
 bird_keep_changes = false
 bird6_keep_changes = false
 bird_changes_counter = 128

anycast_healthchecker/__init__.py

@@ -30,8 +30,6 @@
  'bird6_variable': 'ACAST6_PS_ADVERTISE',
  'bird_reconfigure_cmd': 'sudo /usr/sbin/birdc configure',
  'bird6_reconfigure_cmd': 'sudo /usr/sbin/birdc6 configure',
- 'dummy_ip_prefix': '10.189.200.255/32',
- 'dummy_ip6_prefix': '2001:db8::1/128',
  'bird_keep_changes': 'false',
  'bird6_keep_changes': 'false',
  'bird_changes_counter': 128,

anycast_healthchecker/healthchecker.py

@@ -68,9 +68,6 @@ def __init__(self, config, bird_configuration):
  self.services,
  ip_version)
 
- _ip_prefixes.add(
- self.bird_configuration[ip_version]['dummy_ip_prefix']
- )
  self.ip_prefixes[ip_version] = _ip_prefixes
 
  self.log.info('initialize healthchecker')
@@ -97,8 +94,6 @@ def _update_bird_conf_file(self, operation):
  variable_name = self.bird_configuration[ip_version]['variable_name']
  changes_counter =\
  self.bird_configuration[ip_version]['changes_counter']
- dummy_ip_prefix =\
- self.bird_configuration[ip_version]['dummy_ip_prefix']
 
  try:
  prefixes = get_ip_prefixes_from_bird(config_file)
@@ -107,18 +102,6 @@ def _update_bird_conf_file(self, operation):
  "FATAL error, thus exiting main program", error)
  sys.exit(1)
 
- if not prefixes:
- self.log.error("found empty bird configuration %s, this is a FATAL"
- " error, thus exiting main program", config_file)
- sys.exit(1)
-
- if dummy_ip_prefix not in prefixes:
- self.log.warning("dummy IP prefix %s wasn't found in bird "
- "configuration, adding it. This shouldn't have "
- "happened!", dummy_ip_prefix)
- prefixes.insert(0, dummy_ip_prefix)
- conf_updated = True
-
  ip_prefixes_without_check = set(prefixes).difference(
  self.ip_prefixes[ip_version])
  if ip_prefixes_without_check:
@@ -149,7 +132,6 @@ def _update_bird_conf_file(self, operation):
  # some IP prefixes are either removed or added, create
  # configuration with new data.
  tempname = write_temp_bird_conf(
- dummy_ip_prefix,
  config_file,
  variable_name,
  prefixes
@@ -165,8 +147,7 @@ def _update_bird_conf_file(self, operation):
  self.log.info("Bird configuration for IPv%s is updated",
  ip_version)
 
- # dummy_ip_prefix is always there
- if len(prefixes) == 1:
+ if len(prefixes) == 0:
  self.log.warning("Bird configuration doesn't have IP prefixes for "
  "any of the services we monitor! It means local "
  "node doesn't receive any traffic")

anycast_healthchecker/utils.py

@@ -158,7 +158,6 @@ def ip_prefixes_sanity_check(config, bird_configuration):
  modify_ip_prefixes(config,
  bird_configuration[ip_version]['config_file'],
  bird_configuration[ip_version]['variable_name'],
- bird_configuration[ip_version]['dummy_ip_prefix'],
  bird_configuration[ip_version]['reconfigure_cmd'],
  bird_configuration[ip_version]['keep_changes'],
  bird_configuration[ip_version]['changes_counter'],
@@ -169,7 +168,6 @@ def modify_ip_prefixes(
  config,
  config_file,
  variable_name,
- dummy_ip_prefix,
  reconfigure_cmd,
  keep_changes,
  changes_counter,
@@ -178,14 +176,12 @@ def modify_ip_prefixes(
 
  Depending on the configuration either removes or reports IP prefixes found
  in Bird configuration for which we don't have a service check associated
- with them. Moreover, it adds the dummy IP prefix if it isn't present and
- ensures that the correct variable name is set.
+ with them. Moreover, it ensures that the correct variable name is set.
 
  Arguments:
  config (obg): A configparser object which holds our configuration.
  config_file (str): The file name of bird configuration
  variable_name (str): The name of the variable set in bird configuration
- dummy_ip_prefix (str): The dummy IP prefix, which must be always
  reconfigure_cmd (str): The command to run to trigger a reconfiguration
  on Bird daemon upon successful configuration update
  keep_changes (boolean): To enable keeping a history of changes applied
@@ -215,19 +211,11 @@ def modify_ip_prefixes(
  "correct one %s", _name, variable_name)
  update_bird_conf = True
 
- if dummy_ip_prefix not in ip_prefixes_in_bird:
- log.warning("dummy IP prefix %s is missing from bird configuration "
- "%s, adding it", dummy_ip_prefix, config_file)
- ip_prefixes_in_bird.insert(0, dummy_ip_prefix)
- update_bird_conf = True
-
  # Find IP prefixes in Bird configuration without a check.
  ip_prefixes_with_check = get_ip_prefixes_from_config(
  config,
  services,
  ip_version)
- # dummy_ip_prefix doesn't have a config by design
- ip_prefixes_with_check.add(dummy_ip_prefix)
 
  ip_prefixes_without_check = set(ip_prefixes_in_bird).difference(
  ip_prefixes_with_check)
@@ -251,7 +239,6 @@ def modify_ip_prefixes(
  if keep_changes:
  archive_bird_conf(config_file, changes_counter)
  tempname = write_temp_bird_conf(
- dummy_ip_prefix,
  config_file,
  variable_name,
  ip_prefixes_in_bird
@@ -344,7 +331,7 @@ def configuration_check(config):
  # Catch the case where the directory, under which we store the pid file, is
  # missing.
  if not os.path.isdir(os.path.dirname(pidfile)):
- raise ValueError("{d} doesn't exit".format(d=os.path.dirname(pidfile)))
+ raise ValueError("{d} doesn't exist".format(d=os.path.dirname(pidfile)))
 
  if not isinstance(num_level, int):
  raise ValueError('Invalid log level: {}'.format(log_level))
@@ -481,15 +468,9 @@ def build_bird_configuration(config):
  else:
  config_file = config.get('daemon', 'bird_conf')
 
- dummy_ip_prefix = config.get('daemon', 'dummy_ip_prefix')
- if not valid_ip_prefix(dummy_ip_prefix):
- raise ValueError("invalid dummy IPv4 prefix: {i}"
- .format(i=dummy_ip_prefix))
-
  bird_configuration[4] = {
  'config_file': config_file,
  'variable_name': config.get('daemon', 'bird_variable'),
- 'dummy_ip_prefix': dummy_ip_prefix,
  'reconfigure_cmd': config.get('daemon', 'bird_reconfigure_cmd'),
  'keep_changes': config.getboolean('daemon', 'bird_keep_changes'),
  'changes_counter': config.getint('daemon', 'bird_changes_counter')
@@ -503,14 +484,9 @@ def build_bird_configuration(config):
  else:
  config_file = config.get('daemon', 'bird6_conf')
 
- dummy_ip_prefix = config.get('daemon', 'dummy_ip6_prefix')
- if not valid_ip_prefix(dummy_ip_prefix):
- raise ValueError("invalid dummy IPv6 prefix: {i}"
- .format(i=dummy_ip_prefix))
  bird_configuration[6] = {
  'config_file': config_file,
  'variable_name': config.get('daemon', 'bird6_variable'),
- 'dummy_ip_prefix': dummy_ip_prefix,
  'reconfigure_cmd': config.get('daemon', 'bird6_reconfigure_cmd'),
  'keep_changes': config.getboolean('daemon', 'bird6_keep_changes'),
  'changes_counter': config.getint('daemon', 'bird6_changes_counter')
@@ -778,16 +754,14 @@ def reconfigure_bird(cmd):
  "broken:%s", output)
 
 
-def write_temp_bird_conf(dummy_ip_prefix,
- config_file,
+def write_temp_bird_conf(config_file,
  variable_name,
  prefixes):
  """Write in a temporary file the list of IP-Prefixes.
 
  A failure to create and write the temporary file will exit main program.
 
  Arguments:
- dummy_ip_prefix (str): The dummy IP prefix, which must be always
  config_file (str): The file name of bird configuration
  variable_name (str): The name of the variable set in bird configuration
  prefixes (list): The list of IP-Prefixes to write
@@ -797,8 +771,6 @@ def write_temp_bird_conf(dummy_ip_prefix,
 
  """
  log = logging.getLogger(PROGRAM_NAME)
- comment = ("# {i} is a dummy IP Prefix. It should NOT be used and "
- "REMOVED from the constant.".format(i=dummy_ip_prefix))
 
  # the temporary file must be on the same filesystem as the bird config
  # as we use os.rename to perform an atomic update on the bird config.
@@ -812,13 +784,13 @@ def write_temp_bird_conf(dummy_ip_prefix,
  .format(t=datetime.datetime.now(),
  n=PROGRAM_NAME,
  p=os.getpid()))
- tmpf.write("{c}\n".format(c=comment))
- tmpf.write("define {n} =\n".format(n=variable_name))
- tmpf.write("{s}[\n".format(s=4 * ' '))
- # all entries of the array need a trailing comma except the last
- # one. A single element array doesn't need a trailing comma.
- tmpf.write(',\n'.join([' '*8 + n for n in prefixes]))
- tmpf.write("\n{s}];\n".format(s=4 * ' '))
+ tmpf.write("define {n} = ".format(n=variable_name))
+ if len(prefixes) == 0:
+  tmpf.write("false;\n")
+ else:
+  tmpf.write("\n{s}[\n".format(s=4 * ' '))
+  tmpf.write(',\n'.join([' ' * 8 + n for n in prefixes]))
+  tmpf.write("\n{s}];\n".format(s=4 * ' '))
  except OSError as error:
  log.critical("failed to write temporary file %s: %s. This is a FATAL "
  "error, this exiting main program", tm_file, error)

contrib/puppet/anycast_healthchecker/manifests/init.pp

@@ -55,20 +55,6 @@
 # [*configuration_file*]
 # Read settings for the daemon from
 #
-# [*dummy_ip_prefix*]
-# An IP prefix in the form <IP>/<prefix length> which will be always available in
-# the list defined by ``bird_variable`` to avoid having an empty list.
-# The ``dummy_ip_prefix`` **must not** be used by any service or assigned to the
-# interface set with ``interface`` or configured anywhere on the network as
-# anycast-healthchecker **does not** perform any checks for it.
-#
-# [*dummy_ip6_prefix*]
-# An IPv6 prefix in the form <IPv6>/<prefix length> which will be always
-# available in the list defined by ``bird6_variable`` to avoid having an empty
-# list. The ``dummy_ip6_prefix`` **must not** be used by any service or assigned
-# to the interface set with ``interface`` or configured anywhere on the network as
-# anycast-healthchecker **does not** perform any checks for it.
-#
 # [*group*]
 # Set the UNIX group that anycast-healthchecker is executed.
 # WARNING: Group must exist in the system.
@@ -167,8 +153,6 @@
  $bird6_changes_counter = $::anycast_healthchecker::params::bird6_changes_counter,
  $configuration_dir = $::anycast_healthchecker::params::configuration_dir,
  $configuration_file = $::anycast_healthchecker::params::configuration_file,
- $dummy_ip_prefix = $::anycast_healthchecker::params::dummy_ip_prefix,
- $dummy_ip6_prefix = $::anycast_healthchecker::params::dummy_ip6_prefix,
  $group = $::anycast_healthchecker::params::group,
  $http_server = $::anycast_healthchecker::params::http_server,
  $http_server_port = $::anycast_healthchecker::params::http_server_port,

contrib/puppet/anycast_healthchecker/manifests/params.pp

@@ -18,8 +18,6 @@
  $bird6_changes_counter = 128
  $configuration_dir = '/etc/anycast-healthchecker.d'
  $configuration_file = '/etc/anycast-healthchecker.conf'
- $dummy_ip_prefix = '10.189.200.255/32'
- $dummy_ip6_prefix = '2001:db8::1/128'
  $group = 'healthchecker'
  $http_server = '127.0.0.1'
  $http_server_port = 2813

contrib/puppet/anycast_healthchecker/templates/anycast-healthchecker.conf.erb

@@ -19,15 +19,13 @@ log_backups = <%= @log_backups %>
 log_file = <%= @log_file %>
 stderr_file = <%= @stderr_file %>
 stdout_file = <%= @stdout_file %>
-dummy_ip_prefix = <%= @dummy_ip_prefix %>
 <%- if @ipv6 -%>
 ipv6 = <%= @ipv6 %>
 bird6_conf = <%= @bird6_conf %>
 bird6_variable = <%= @bird6_variable %>
 bird6_reconfigure_cmd = <%= @bird6_reconfigure_cmd %>
 bird6_keep_changes = <%= @bird6_keep_changes %>
 bird6_changes_counter = <%= @bird6_changes_counter %>
-dummy_ip6_prefix = <%= @dummy_ip6_prefix %>
 <%- end -%>
 <%- if @json_logging -%>
 json_logging = true

debian/patches/anycast-healthchecker.conf.patch

@@ -16,8 +16,6 @@ index 35f08bc..bc9fea7 100644
 -bird6_reconfigure_cmd = sudo /usr/sbin/birdc6 configure
 +bird_reconfigure_cmd = /usr/sbin/birdc configure
 +bird6_reconfigure_cmd = /usr/sbin/birdc6 configure
- dummy_ip_prefix = 10.189.200.255/32
- dummy_ip6_prefix = 2001:db8::1/128
  bird_keep_changes = false
 @@ -18,7 +18,7 @@ bird6_keep_changes = false
  bird_changes_counter = 128

local_run.sh

@@ -42,12 +42,10 @@ bird_variable = ACAST_PS_ADVERTISE
 bird_keep_changes = true
 bird_changes_counter = 6
 bird_reconfigure_cmd = /usr/bin/sudo /usr/sbin/birdc configure
-dummy_ip_prefix = 10.189.200.255/32
 
 ipv6 = true
 bird6_conf = ${TEST_DIR}/var/lib/anycast-healthchecker/6/anycast-prefixes.conf
 bird6_variable = ACAST6_PS_ADVERTISE
-dummy_ip6_prefix = 2001:db8::1/128
 bird6_reconfigure_cmd = sudo /usr/sbin/birdc6 configure
 bird6_keep_changes = true
 bird6_changes_counter = 6