Class: Synapse::ConfigGenerator::Haproxy

Inherits:
BaseGenerator show all
Includes:
Logging
Defined in:
lib/synapse/config_generator/haproxy.rb

Constant Summary collapse

NAME = 
'haproxy'.freeze
HAPROXY_CMD_BATCH_SIZE = 
4
SECTION_FIELDS =

these come from the documentation for haproxy (1.5 and 1.6) haproxy.1wt.eu/download/1.5/doc/configuration.txt haproxy.1wt.eu/download/1.6/doc/configuration.txt

{
  "backend" => [
    "acl",
    "appsession",
    "balance",
    "bind-process",
    "block",
    "compression",
    "contimeout",
    "cookie",
    "default-server",
    "description",
    "disabled",
    "dispatch",
    "email-alert from",
    "email-alert level",
    "email-alert mailers",
    "email-alert myhostname",
    "email-alert to",
    "enabled",
    "errorfile",
    "errorloc",
    "errorloc302",
    "errorloc303",
    "force-persist",
    "fullconn",
    "grace",
    "hash-type",
    "http-check disable-on-404",
    "http-check expect",
    "http-check send-state",
    "http-request",
    "http-response",
    "http-send-name-header",
    "http-reuse",
    "http-send-name-header",
    "id",
    "ignore-persist",
    "load-server-state-from-file",
    "log",
    "log-tag",
    "max-keep-alive-queue",
    "mode",
    "no log",
    "no option abortonclose",
    "no option accept-invalid-http-response",
    "no option allbackups",
    "no option allredisp",
    "no option checkcache",
    "no option forceclose",
    "no option forwardfor",
    "no option http-buffer-request",
    "no option http-keep-alive",
    "no option http-no-delay",
    "no option http-pretend-keepalive",
    "no option http-server-close",
    "no option http-tunnel",
    "no option httpchk",
    "no option httpclose",
    "no option httplog",
    "no option http_proxy",
    "no option independent-streams",
    "no option lb-agent-chk",
    "no option ldap-check",
    "no option external-check",
    "no option log-health-checks",
    "no option mysql-check",
    "no option pgsql-check",
    "no option nolinger",
    "no option originalto",
    "no option persist",
    "no option pgsql-check",
    "no option prefer-last-server",
    "no option redispatch",
    "no option redis-check",
    "no option smtpchk",
    "no option splice-auto",
    "no option splice-request",
    "no option splice-response",
    "no option srvtcpka",
    "no option ssl-hello-chk",
    "no option tcp-check",
    "no option tcp-smart-connect",
    "no option tcpka",
    "no option tcplog",
    "no option transparent",
    "option abortonclose",
    "option accept-invalid-http-response",
    "option allbackups",
    "option allredisp",
    "option checkcache",
    "option forceclose",
    "option forwardfor",
    "option http-buffer-request",
    "option http-keep-alive",
    "option http-no-delay",
    "option http-pretend-keepalive",
    "option http-server-close",
    "option http-tunnel",
    "option httpchk",
    "option httpclose",
    "option httplog",
    "option http_proxy",
    "option independent-streams",
    "option lb-agent-chk",
    "option ldap-check",
    "option external-check",
    "option log-health-checks",
    "option mysql-check",
    "option pgsql-check",
    "option nolinger",
    "option originalto",
    "option persist",
    "option pgsql-check",
    "option prefer-last-server",
    "option redispatch",
    "option redis-check",
    "option smtpchk",
    "option splice-auto",
    "option splice-request",
    "option splice-response",
    "option srvtcpka",
    "option ssl-hello-chk",
    "option tcp-check",
    "option tcp-smart-connect",
    "option tcpka",
    "option tcplog",
    "option transparent",
    "external-check command",
    "external-check path",
    "persist rdp-cookie",
    "redirect",
    "redisp",
    "redispatch",
    "reqadd",
    "reqallow",
    "reqdel",
    "reqdeny",
    "reqiallow",
    "reqidel",
    "reqideny",
    "reqipass",
    "reqirep",
    "reqisetbe",
    "reqitarpit",
    "reqpass",
    "reqrep",
    "reqsetbe",
    "reqtarpit",
    "retries",
    "rspadd",
    "rspdel",
    "rspdeny",
    "rspidel",
    "rspideny",
    "rspirep",
    "rsprep",
    "server",
    "server-state-file-name",
    "source",
    "srvtimeout",
    "stats admin",
    "stats auth",
    "stats enable",
    "stats hide-version",
    "stats http-request",
    "stats realm",
    "stats refresh",
    "stats scope",
    "stats show-desc",
    "stats show-legends",
    "stats show-node",
    "stats uri",
    "stick match",
    "stick on",
    "stick store-request",
    "stick store-response",
    "stick-table",
    "tcp-check connect",
    "tcp-check expect",
    "tcp-check send",
    "tcp-check send-binary",
    "tcp-request content",
    "tcp-request inspect-delay",
    "tcp-response content",
    "tcp-response inspect-delay",
    "timeout check",
    "timeout connect",
    "timeout contimeout",
    "timeout http-keep-alive",
    "timeout http-request",
    "timeout queue",
    "timeout server",
    "timeout server-fin",
    "timeout srvtimeout",
    "timeout tarpit",
    "timeout tunnel",
    "transparent",
    "use-server"
  ],
  "defaults" => [
    "backlog",
    "balance",
    "bind-process",
    "clitimeout",
    "compression",
    "contimeout",
    "cookie",
    "default-server",
    "default_backend",
    "disabled",
    "email-alert from",
    "email-alert level",
    "email-alert mailers",
    "email-alert myhostname",
    "email-alert to",
    "enabled",
    "errorfile",
    "errorloc",
    "errorloc302",
    "errorloc303",
    "fullconn",
    "grace",
    "hash-type",
    "http-check disable-on-404",
    "http-check send-state",
    "http-reuse",
    "load-server-state-from-file",
    "log",
    "log-format",
    "log-format-sd",
    "log-tag",
    "max-keep-alive-queue",
    "maxconn",
    "mode",
    "monitor-net",
    "monitor-uri",
    "no log",
    "no option abortonclose",
    "no option accept-invalid-http-request",
    "no option accept-invalid-http-response",
    "no option allbackups",
    "no option allredisp",
    "no option checkcache",
    "no option clitcpka",
    "no option contstats",
    "no option dontlog-normal",
    "no option dontlognull",
    "no option forceclose",
    "no option forwardfor",
    "no option http-buffer-request",
    "no option http-ignore-probes",
    "no option http-keep-alive",
    "no option http-no-delay",
    "no option http-pretend-keepalive",
    "no option http-server-close",
    "no option http-tunnel",
    "no option http-use-proxy-header",
    "no option httpchk",
    "no option httpclose",
    "no option httplog",
    "no option http_proxy",
    "no option independent-streams",
    "no option lb-agent-chk",
    "no option ldap-check",
    "no option external-check",
    "no option log-health-checks",
    "no option log-separate-errors",
    "no option logasap",
    "no option mysql-check",
    "no option pgsql-check",
    "no option nolinger",
    "no option originalto",
    "no option persist",
    "no option pgsql-check",
    "no option prefer-last-server",
    "no option redispatch",
    "no option redis-check",
    "no option smtpchk",
    "no option socket-stats",
    "no option splice-auto",
    "no option splice-request",
    "no option splice-response",
    "no option srvtcpka",
    "no option ssl-hello-chk",
    "no option tcp-check",
    "no option tcp-smart-accept",
    "no option tcp-smart-connect",
    "no option tcpka",
    "no option tcplog",
    "no option transparent",
    "option abortonclose",
    "option accept-invalid-http-request",
    "option accept-invalid-http-response",
    "option allbackups",
    "option allredisp",
    "option checkcache",
    "option clitcpka",
    "option contstats",
    "option dontlog-normal",
    "option dontlognull",
    "option forceclose",
    "option forwardfor",
    "option http-buffer-request",
    "option http-ignore-probes",
    "option http-keep-alive",
    "option http-no-delay",
    "option http-pretend-keepalive",
    "option http-server-close",
    "option http-tunnel",
    "option http-use-proxy-header",
    "option httpchk",
    "option httpclose",
    "option httplog",
    "option http_proxy",
    "option independent-streams",
    "option lb-agent-chk",
    "option ldap-check",
    "option external-check",
    "option log-health-checks",
    "option log-separate-errors",
    "option logasap",
    "option mysql-check",
    "option pgsql-check",
    "option nolinger",
    "option originalto",
    "option persist",
    "option pgsql-check",
    "option prefer-last-server",
    "option redispatch",
    "option redis-check",
    "option smtpchk",
    "option socket-stats",
    "option splice-auto",
    "option splice-request",
    "option splice-response",
    "option srvtcpka",
    "option ssl-hello-chk",
    "option tcp-check",
    "option tcp-smart-accept",
    "option tcp-smart-connect",
    "option tcpka",
    "option tcplog",
    "option transparent",
    "external-check command",
    "external-check path",
    "persist rdp-cookie",
    "rate-limit sessions",
    "redisp",
    "redispatch",
    "retries",
    "server-state-file-name",
    "source",
    "srvtimeout",
    "stats auth",
    "stats enable",
    "stats hide-version",
    "stats realm",
    "stats refresh",
    "stats scope",
    "stats show-desc",
    "stats show-legends",
    "stats show-node",
    "stats uri",
    "timeout check",
    "timeout client",
    "timeout client-fin",
    "timeout clitimeout",
    "timeout connect",
    "timeout contimeout",
    "timeout http-keep-alive",
    "timeout http-request",
    "timeout queue",
    "timeout server",
    "timeout server-fin",
    "timeout srvtimeout",
    "timeout tarpit",
    "timeout tunnel",
    "transparent",
    "unique-id-format",
    "unique-id-header"
  ],
  "frontend" => [
    "acl",
    "backlog",
    "bind",
    "bind-process",
    "block",
    "capture cookie",
    "capture request header",
    "capture response header",
    "clitimeout",
    "compression",
    "declare capture",
    "default_backend",
    "description",
    "disabled",
    "email-alert from",
    "email-alert level",
    "email-alert mailers",
    "email-alert myhostname",
    "email-alert to",
    "enabled",
    "errorfile",
    "errorloc",
    "errorloc302",
    "errorloc303",
    "force-persist",
    "grace",
    "http-request",
    "http-response",
    "id",
    "ignore-persist",
    "log",
    "log-format",
    "log-format-sd",
    "log-tag",
    "maxconn",
    "mode",
    "monitor fail",
    "monitor-net",
    "monitor-uri",
    "no log",
    "no option accept-invalid-http-request",
    "no option clitcpka",
    "no option contstats",
    "no option dontlog-normal",
    "no option dontlognull",
    "no option forceclose",
    "no option forwardfor",
    "no option http-buffer-request",
    "no option http-ignore-probes",
    "no option http-keep-alive",
    "no option http-no-delay",
    "no option http-pretend-keepalive",
    "no option http-server-close",
    "no option http-tunnel",
    "no option http-use-proxy-header",
    "no option httpclose",
    "no option httplog",
    "no option http_proxy",
    "no option independent-streams",
    "no option log-separate-errors",
    "no option logasap",
    "no option nolinger",
    "no option originalto",
    "no option socket-stats",
    "no option splice-auto",
    "no option splice-request",
    "no option splice-response",
    "no option tcp-smart-accept",
    "no option tcpka",
    "no option tcplog",
    "option accept-invalid-http-request",
    "option clitcpka",
    "option contstats",
    "option dontlog-normal",
    "option dontlognull",
    "option forceclose",
    "option forwardfor",
    "option http-buffer-request",
    "option http-ignore-probes",
    "option http-keep-alive",
    "option http-no-delay",
    "option http-pretend-keepalive",
    "option http-server-close",
    "option http-tunnel",
    "option http-use-proxy-header",
    "option httpclose",
    "option httplog",
    "option http_proxy",
    "option independent-streams",
    "option log-separate-errors",
    "option logasap",
    "option nolinger",
    "option originalto",
    "option socket-stats",
    "option splice-auto",
    "option splice-request",
    "option splice-response",
    "option tcp-smart-accept",
    "option tcpka",
    "option tcplog",
    "rate-limit sessions",
    "redirect",
    "reqadd",
    "reqallow",
    "reqdel",
    "reqdeny",
    "reqiallow",
    "reqidel",
    "reqideny",
    "reqipass",
    "reqirep",
    "reqisetbe",
    "reqitarpit",
    "reqpass",
    "reqrep",
    "reqsetbe",
    "reqtarpit",
    "rspadd",
    "rspdel",
    "rspdeny",
    "rspidel",
    "rspideny",
    "rspirep",
    "rsprep",
    "stats admin",
    "stats auth",
    "stats enable",
    "stats hide-version",
    "stats http-request",
    "stats realm",
    "stats refresh",
    "stats scope",
    "stats show-desc",
    "stats show-legends",
    "stats show-node",
    "stats uri",
    "tcp-request connection",
    "tcp-request content",
    "tcp-request inspect-delay",
    "timeout client",
    "timeout client-fin",
    "timeout clitimeout",
    "timeout http-keep-alive",
    "timeout http-request",
    "timeout tarpit",
    "unique-id-format",
    "unique-id-header",
    "use_backend"
  ],
  "listen" => [
    "acl",
    "appsession",
    "backlog",
    "balance",
    "bind",
    "bind-process",
    "block",
    "capture cookie",
    "capture request header",
    "capture response header",
    "clitimeout",
    "compression",
    "contimeout",
    "cookie",
    "declare capture",
    "default-server",
    "default_backend",
    "description",
    "disabled",
    "dispatch",
    "email-alert from",
    "email-alert level",
    "email-alert mailers",
    "email-alert myhostname",
    "email-alert to",
    "enabled",
    "errorfile",
    "errorloc",
    "errorloc302",
    "errorloc303",
    "force-persist",
    "fullconn",
    "grace",
    "hash-type",
    "http-check disable-on-404",
    "http-check expect",
    "http-check send-state",
    "http-request",
    "http-response",
    "http-send-name-header",
    "http-reuse",
    "http-send-name-header",
    "id",
    "ignore-persist",
    "load-server-state-from-file",
    "log",
    "log-format",
    "log-format-sd",
    "log-tag",
    "max-keep-alive-queue",
    "maxconn",
    "mode",
    "monitor fail",
    "monitor-net",
    "monitor-uri",
    "no log",
    "no option abortonclose",
    "no option accept-invalid-http-request",
    "no option accept-invalid-http-response",
    "no option allbackups",
    "no option allredisp",
    "no option checkcache",
    "no option clitcpka",
    "no option contstats",
    "no option dontlog-normal",
    "no option dontlognull",
    "no option forceclose",
    "no option forwardfor",
    "no option http-buffer-request",
    "no option http-ignore-probes",
    "no option http-keep-alive",
    "no option http-no-delay",
    "no option http-pretend-keepalive",
    "no option http-server-close",
    "no option http-tunnel",
    "no option http-use-proxy-header",
    "no option httpchk",
    "no option httpclose",
    "no option httplog",
    "no option http_proxy",
    "no option independent-streams",
    "no option lb-agent-chk",
    "no option ldap-check",
    "no option external-check",
    "no option log-health-checks",
    "no option log-separate-errors",
    "no option logasap",
    "no option mysql-check",
    "no option pgsql-check",
    "no option nolinger",
    "no option originalto",
    "no option persist",
    "no option pgsql-check",
    "no option prefer-last-server",
    "no option redispatch",
    "no option redis-check",
    "no option smtpchk",
    "no option socket-stats",
    "no option splice-auto",
    "no option splice-request",
    "no option splice-response",
    "no option srvtcpka",
    "no option ssl-hello-chk",
    "no option tcp-check",
    "no option tcp-smart-accept",
    "no option tcp-smart-connect",
    "no option tcpka",
    "no option tcplog",
    "no option transparent",
    "option abortonclose",
    "option accept-invalid-http-request",
    "option accept-invalid-http-response",
    "option allbackups",
    "option allredisp",
    "option checkcache",
    "option clitcpka",
    "option contstats",
    "option dontlog-normal",
    "option dontlognull",
    "option forceclose",
    "option forwardfor",
    "option http-buffer-request",
    "option http-ignore-probes",
    "option http-keep-alive",
    "option http-no-delay",
    "option http-pretend-keepalive",
    "option http-server-close",
    "option http-tunnel",
    "option http-use-proxy-header",
    "option httpchk",
    "option httpclose",
    "option httplog",
    "option http_proxy",
    "option independent-streams",
    "option lb-agent-chk",
    "option ldap-check",
    "option external-check",
    "option log-health-checks",
    "option log-separate-errors",
    "option logasap",
    "option mysql-check",
    "option pgsql-check",
    "option nolinger",
    "option originalto",
    "option persist",
    "option pgsql-check",
    "option prefer-last-server",
    "option redispatch",
    "option redis-check",
    "option smtpchk",
    "option socket-stats",
    "option splice-auto",
    "option splice-request",
    "option splice-response",
    "option srvtcpka",
    "option ssl-hello-chk",
    "option tcp-check",
    "option tcp-smart-accept",
    "option tcp-smart-connect",
    "option tcpka",
    "option tcplog",
    "option transparent",
    "external-check command",
    "external-check path",
    "persist rdp-cookie",
    "rate-limit sessions",
    "redirect",
    "redisp",
    "redispatch",
    "reqadd",
    "reqallow",
    "reqdel",
    "reqdeny",
    "reqiallow",
    "reqidel",
    "reqideny",
    "reqipass",
    "reqirep",
    "reqisetbe",
    "reqitarpit",
    "reqpass",
    "reqrep",
    "reqsetbe",
    "reqtarpit",
    "retries",
    "rspadd",
    "rspdel",
    "rspdeny",
    "rspidel",
    "rspideny",
    "rspirep",
    "rsprep",
    "server",
    "server-state-file-name",
    "source",
    "srvtimeout",
    "stats admin",
    "stats auth",
    "stats enable",
    "stats hide-version",
    "stats http-request",
    "stats realm",
    "stats refresh",
    "stats scope",
    "stats show-desc",
    "stats show-legends",
    "stats show-node",
    "stats uri",
    "stick match",
    "stick on",
    "stick store-request",
    "stick store-response",
    "stick-table",
    "tcp-check connect",
    "tcp-check expect",
    "tcp-check send",
    "tcp-check send-binary",
    "tcp-request connection",
    "tcp-request content",
    "tcp-request inspect-delay",
    "tcp-response content",
    "tcp-response inspect-delay",
    "timeout check",
    "timeout client",
    "timeout client-fin",
    "timeout clitimeout",
    "timeout connect",
    "timeout contimeout",
    "timeout http-keep-alive",
    "timeout http-request",
    "timeout queue",
    "timeout server",
    "timeout server-fin",
    "timeout srvtimeout",
    "timeout tarpit",
    "timeout tunnel",
    "transparent",
    "unique-id-format",
    "unique-id-header",
    "use_backend",
    "use-server"
  ]
}.freeze
DEFAULT_STATE_FILE_TTL =

24 hours

(60 * 60 * 24).freeze
STATE_FILE_UPDATE_INTERVAL =

iterations; not a unit of time

60.freeze
DEFAULT_BIND_ADDRESS = 
'localhost'
MAX_SERVER_ID =

It’s unclear how many servers HAProxy can have in one backend, but 65k should be enough for anyone right (famous last words)?

(2**16 - 1).freeze

Instance Attribute Summary

Attributes inherited from BaseGenerator

#opts

Instance Method Summary collapse

Methods included from Logging

configure_logger_for, #log, logger_for

Methods inherited from BaseGenerator

#name

Constructor Details

#initialize(opts) ⇒ Haproxy

Returns a new instance of Haproxy.



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# File 'lib/synapse/config_generator/haproxy.rb', line 804

def initialize(opts)
  super(opts)

  %w{global defaults}.each do |req|
    raise ArgumentError, "haproxy requires a #{req} section" if !opts.has_key?(req)
  end

  @opts['do_writes'] = true unless @opts.key?('do_writes')
  @opts['do_socket'] = true unless @opts.key?('do_socket')
  @opts['do_reloads'] = true unless @opts.key?('do_reloads')

  req_pairs = {
    'do_writes' => 'config_file_path',
    'do_socket' => 'socket_file_path',
    'do_reloads' => 'reload_command'
  }

  req_pairs.each do |cond, req|
    if @opts[cond]
      raise ArgumentError, "the `#{req}` option is required when `#{cond}` is true" unless @opts[req]
    end
  end

  # socket_file_path can be a string or a list
  # lets make a new option which is always a list (plural)
  @opts['socket_file_paths'] = [@opts['socket_file_path']].flatten

  # how to restart haproxy
  @restart_interval = @opts.fetch('restart_interval', 2).to_i
  @restart_jitter = @opts.fetch('restart_jitter', 0).to_f
  @restart_required = true

  # virtual clock bookkeeping for controlling how often haproxy restarts
  @time = 0
  @next_restart = @time

  # a place to store the parsed haproxy config from each watcher
  @watcher_configs = {}

  # a place to store generated frontend and backend stanzas
  @frontends_cache = {}
  @backends_cache = {}
  @watcher_revisions = {}

  @state_file_path = @opts['state_file_path']
  @state_file_ttl = @opts.fetch('state_file_ttl', DEFAULT_STATE_FILE_TTL).to_i

  # For giving consistent orders, even if they are random
  @server_order_seed = @opts.fetch('server_order_seed', rand(2000)).to_i
  @max_server_id = @opts.fetch('max_server_id', MAX_SERVER_ID).to_i
  # Map of backend names -> hash of HAProxy server names -> puids
  # (server->id aka "name") to their proxy unique id (server->puid aka "id")
  @server_id_map = Hash.new{|h,k| h[k] = {}}
  # Map of backend names -> hash of HAProxy server puids -> names
  # (server->puid aka "id") to their name (server->id aka "name")
  @id_server_map = Hash.new{|h,k| h[k] = {}}

end

Instance Method Details

#construct_name(backend) ⇒ Object

used to build unique, consistent haproxy names for backends



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# File 'lib/synapse/config_generator/haproxy.rb', line 1299

def construct_name(backend)
  name = "#{backend['host']}:#{backend['port']}"
  if backend['name'] && !backend['name'].empty?
    name = "#{backend['name']}_#{name}"
  end

  return name
end

#find_next_id(watcher_name, backend_name) ⇒ Object 



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# File 'lib/synapse/config_generator/haproxy.rb', line 1146

def find_next_id(watcher_name, backend_name)
  probe = nil
  if @server_id_map[watcher_name].size >= @max_server_id
    log.error "synapse: ran out of server ids for #{watcher_name}, if you need more increase the max_server_id option"
    return probe
  end

  probe = 1

  while @id_server_map[watcher_name].include?(probe)
    probe = (probe % @max_server_id) + 1
  end

  probe
end

#generate_backend_stanza(watcher, config) ⇒ Object 



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# File 'lib/synapse/config_generator/haproxy.rb', line 1049

def generate_backend_stanza(watcher, config)
  backends = {}

  # The ordering here is important.  First we add all the backends in the
  # disabled state...
  seen.fetch(watcher.name, []).each do |backend_name, backend|
    backends[backend_name] = backend.merge('enabled' => false)
    # We remember the haproxy_server_id from a previous reload here.
    # Note though that if live servers below define haproxy_server_id
    # that overrides the remembered value
    @server_id_map[watcher.name][backend_name] ||= backends[backend_name]['haproxy_server_id']
    @id_server_map[watcher.name][@server_id_map[watcher.name][backend_name]] = backend_name if @server_id_map[watcher.name][backend_name]
  end

  # ... and then we overwite any backends that the watchers know about,
  # setting the enabled state.
  watcher.backends.each do |backend|
    backend_name = construct_name(backend)
    # If we have information in the state file that allows us to detect
    # server option changes, use that to potentially force a restart
    if backends.has_key?(backend_name)
      old_backend = backends[backend_name]
      if (old_backend.fetch('haproxy_server_options', "") !=
          backend.fetch('haproxy_server_options', ""))
        log.info "synapse: restart required because haproxy_server_options changed for #{backend_name}"
        @restart_required = true
      end
    end

    backends[backend_name] = backend.merge('enabled' => true)

    # If the the registry defines the haproxy_server_id that must be preferred.
    # Note that the order here is important, because if haproxy_server_options
    # does define an id, then we will write that out below, so that must be what
    # is in the id_map as well.
    @server_id_map[watcher.name][backend_name] = backend['haproxy_server_id'].to_i if backend['haproxy_server_id']
    server_opts = (backend['haproxy_server_options'] || 'no match').split(' ')
    @server_id_map[watcher.name][backend_name] = server_opts[server_opts.index('id') + 1].to_i if server_opts.include?('id')
    @id_server_map[watcher.name][@server_id_map[watcher.name][backend_name]] = backend_name
  end

  # Now that we know the maximum possible existing haproxy_server_id for
  # this backend, we can set any that don't exist yet.
  watcher.backends.each do |backend|
    backend_name = construct_name(backend)
    @server_id_map[watcher.name][backend_name] ||= find_next_id(watcher.name, backend_name)
    @id_server_map[watcher.name][@server_id_map[watcher.name][backend_name]] = backend_name
  end
  # Remove any servers that don't exist anymore from the server_id_map
  # to control memory growth
  @server_id_map[watcher.name].keep_if { |server_name| backends.has_key?(server_name) }
  @id_server_map[watcher.name].keep_if { |_, server_name| @server_id_map[watcher.name][server_name] }

  if watcher.backends.empty?
    log.debug "synapse: no backends found for watcher #{watcher.name}"
  end

  watcher_config = watcher.config_for_generator[name]
  keys = case watcher_config['backend_order']
  when 'asc'
    backends.keys.sort
  when 'desc'
    backends.keys.sort.reverse
  when 'no_shuffle'
    backends.keys
  else
    backends.keys.shuffle(random: Random.new(@server_order_seed))
  end

  stanza = [
    "\nbackend #{watcher_config.fetch('backend_name', watcher.name)}",
    config.map {|c| "\t#{c}"},
    keys.map {|backend_name|
      backend = backends[backend_name]
      b = "\tserver #{backend_name} #{backend['host']}:#{backend['port']}"

      # Again, if the registry defines an id, we can't set it.
      has_id = (backend['haproxy_server_options'] || 'no match').split(' ').include?('id')
      if (!has_id && @server_id_map[watcher.name][backend_name])
        b = "#{b} id #{@server_id_map[watcher.name][backend_name]}"
      end

      unless config.include?('mode tcp')
        b = case watcher_config['cookie_value_method']
        when 'hash'
          b = "#{b} cookie #{Digest::SHA1.hexdigest(backend_name)}"
        else
          b = "#{b} cookie #{backend_name}"
        end
      end
      b = "#{b} #{watcher_config['server_options']}" if watcher_config['server_options']
      b = "#{b} #{backend['haproxy_server_options']}" if backend['haproxy_server_options']
      b = "#{b} disabled" unless backend['enabled']
      b }
  ]
end

#generate_base_config ⇒ Object

generates the global and defaults sections of the config file



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# File 'lib/synapse/config_generator/haproxy.rb', line 957

def generate_base_config
  base_config = ["# auto-generated by synapse at #{Time.now}\n"]

  %w{global defaults}.each do |section|
    base_config << "#{section}"
    opts[section].each do |option|
      base_config << "\t#{option}"
    end
  end

  if opts['extra_sections']
    opts['extra_sections'].each do |title, section|
      base_config << "\n#{title}"
      section.each do |option|
        base_config << "\t#{option}"
      end
    end
  end

  return base_config
end

#generate_config(watchers) ⇒ Object

generates a new config based on the state of the watchers



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# File 'lib/synapse/config_generator/haproxy.rb', line 911

def generate_config(watchers)
  new_config = generate_base_config
  shared_frontend_lines = generate_shared_frontend

  watchers.each do |watcher|
    watcher_config = watcher.config_for_generator[name]
    @watcher_configs[watcher.name] ||= parse_watcher_config(watcher)
    next if watcher_config['disabled']

    regenerate = watcher.revision != @watcher_revisions[watcher.name] ||
                 @frontends_cache[watcher.name].nil? ||
                 @backends_cache[watcher.name].nil?
    if regenerate
      @frontends_cache[watcher.name] = generate_frontend_stanza(watcher, @watcher_configs[watcher.name]['frontend'])
      @backends_cache[watcher.name] = generate_backend_stanza(watcher, @watcher_configs[watcher.name]['backend'])
      @watcher_revisions[watcher.name] = watcher.revision
    end
    new_config << @frontends_cache[watcher.name] << @backends_cache[watcher.name]

    if watcher_config.include?('shared_frontend')
      if opts['shared_frontend'] == nil
        log.warn "synapse: service #{watcher.name} contains a shared frontend section but the base config does not! skipping."
      else
        tabbed_shared_frontend = watcher_config['shared_frontend'].map{|l| "\t#{l}"}
        shared_frontend_lines << validate_haproxy_stanza(
          tabbed_shared_frontend, "frontend", "shared frontend section for #{watcher.name}"
        )
      end
    end
  end
  new_config << shared_frontend_lines.flatten if shared_frontend_lines

  log.debug "synapse: new haproxy config: #{new_config}"
  return new_config.flatten.join("\n")
end

#generate_frontend_stanza(watcher, config) ⇒ Object

generates an individual stanza for a particular watcher



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# File 'lib/synapse/config_generator/haproxy.rb', line 1014

def generate_frontend_stanza(watcher, config)
  watcher_config = watcher.config_for_generator[name]
  unless watcher_config.has_key?("port")
    log.debug "synapse: not generating frontend stanza for watcher #{watcher.name} because it has no port defined"
    return []
  else
    port = watcher_config['port']
  end


  bind_address = (
    watcher_config['bind_address'] ||
    opts['bind_address'] ||
    DEFAULT_BIND_ADDRESS
  )
  backend_name = watcher_config.fetch('backend_name', watcher.name)

  # Explicit null value passed indicating no port needed
  # For example if the bind_address is a unix port
  bind_port = port.nil? ? '' : ":#{port}"

  bind_line = [
    "\tbind",
    "#{bind_address}#{bind_port}",
    watcher_config['bind_options']
  ].compact.join(' ')

  stanza = [
    "\nfrontend #{watcher.name}",
    config.map {|c| "\t#{c}"},
    bind_line,
    "\tdefault_backend #{backend_name}"
  ]
end

#generate_shared_frontend ⇒ Object

pull out the shared frontend section if any



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# File 'lib/synapse/config_generator/haproxy.rb', line 948

def generate_shared_frontend
  return nil unless opts.include?('shared_frontend')
  log.debug "synapse: found a shared frontend section"
  shared_frontend_lines = ["\nfrontend shared-frontend"]
  shared_frontend_lines << validate_haproxy_stanza(opts['shared_frontend'].map{|l| "\t#{l}"}, "frontend", "shared frontend")
  return shared_frontend_lines
end

#normalize_watcher_provided_config(service_watcher_name, service_watcher_config) ⇒ Object 



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# File 'lib/synapse/config_generator/haproxy.rb', line 863

def normalize_watcher_provided_config(service_watcher_name, service_watcher_config)
  service_watcher_config = super(service_watcher_name, service_watcher_config)
  defaults = {
    'server_options' => "",
    'server_port_override' => nil,
    'backend' => [],
    'frontend' => [],
    'listen' => [],
  }
  unless service_watcher_config.include?('port')
    log.warn "synapse: service #{service_watcher_name}: haproxy config does not include a port; only backend sections for the service will be created; you must move traffic there manually using configuration in `extra_sections`"
  end
  defaults.merge(service_watcher_config)
end

#parse_watcher_config(watcher) ⇒ Object

split the haproxy config in each watcher into fields applicable in frontend and backend sections



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# File 'lib/synapse/config_generator/haproxy.rb', line 981

def parse_watcher_config(watcher)
  config = {}
  watcher_config = watcher.config_for_generator[name]
  %w{frontend backend}.each do |section|
    config[section] = watcher_config[section] || []

    # copy over the settings from the 'listen' section that pertain to section
    config[section].concat(
      watcher_config['listen'].select {|setting|
        parsed_setting = setting.strip.gsub(/\s+/, ' ').downcase
        SECTION_FIELDS[section].any? {|field| parsed_setting.start_with?(field)}
      })

    # pick only those fields that are valid and warn about the invalid ones
    config[section] = validate_haproxy_stanza(config[section], section, watcher.name)
  end

  return config
end

#read_state_file ⇒ Object 



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# File 'lib/synapse/config_generator/haproxy.rb', line 1365

def read_state_file
  # Some versions of JSON return nil on an empty file ...
  JSON.load(File.read(@state_file_path)) || {}
rescue StandardError => e
  # It's ok if the state file doesn't exist or contains invalid data
  # The state file will be rebuilt automatically
  {}
end

#restart ⇒ Object

restarts haproxy if the time is right



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# File 'lib/synapse/config_generator/haproxy.rb', line 1278

def restart
  if @time < @next_restart
    log.info "synapse: at time #{@time} waiting until #{@next_restart} to restart"
    return
  end

  @next_restart = @time + @restart_interval
  @next_restart += rand(@restart_jitter * @restart_interval + 1)

  # do the actual restart
  res = `#{opts['reload_command']}`.chomp
  unless $?.success?
    log.error "failed to reload haproxy via #{opts['reload_command']}: #{res}"
    return
  end
  log.info "synapse: restarted haproxy"

  @restart_required = false
end

#seen ⇒ Object

methods for managing the state file



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# File 'lib/synapse/config_generator/haproxy.rb', line 1311

def seen
  # if we don't support the state file, return nothing
  return {} if @state_file_path.nil?

  # if we've never needed the backends, now is the time to load them
  @seen = read_state_file if @seen.nil?

  @seen
end

#talk_to_socket(socket_file_path, command) ⇒ Object 



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# File 'lib/synapse/config_generator/haproxy.rb', line 1162

def talk_to_socket(socket_file_path, command)
  s = UNIXSocket.new(socket_file_path)
  s.write(command)
  s.read
ensure
  s.close if s
end

#tick(watchers) ⇒ Object 



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# File 'lib/synapse/config_generator/haproxy.rb', line 878

def tick(watchers)
  if (@time % STATE_FILE_UPDATE_INTERVAL) == 0
    update_state_file(watchers)
  end

  @time += 1

  # We potentially have to restart if the restart was rate limited
  # in the original call to update_config
  restart if opts['do_reloads'] && @restart_required
end

#update_backends_at(socket_file_path, watchers) ⇒ Object

tries to set active backends via haproxy’s stats socket because we can’t add backends via the socket, we might still need to restart haproxy



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# File 'lib/synapse/config_generator/haproxy.rb', line 1172

def update_backends_at(socket_file_path, watchers)
  # first, get a list of existing servers for various backends
  begin
    stat_command = "show stat\n"
    info = talk_to_socket(socket_file_path, stat_command)
  rescue StandardError => e
    log.warn "synapse: restart required because socket command #{stat_command} failed "\
             "with error #{e.inspect}"
    @restart_required = true
    return
  end

  # parse the stats output to get current backends
  cur_backends = {}
  re = Regexp.new('^(.+?),(.+?),(?:.*?,){15}(.+?),')

  info.split("\n").each do |line|
    next if line[0] == '#'

    name, addr, state = re.match(line)[1..3]

    next if ['FRONTEND', 'BACKEND'].include?(addr)

    cur_backends[name] ||= {}
    cur_backends[name][addr] = state
  end

  # build a list of backends that should be enabled
  enabled_backends = {}
  watchers.each do |watcher|
    enabled_backends[watcher.name] = Set.new
    next if watcher.backends.empty?
    next if watcher.config_for_generator[name]['disabled']

    unless cur_backends.include? watcher.name
      log.info "synapse: restart required because we added new section #{watcher.name}"
      @restart_required = true
      next
    end

    watcher.backends.each do |backend|
      backend_name = construct_name(backend)
      if cur_backends[watcher.name].include? backend_name
        enabled_backends[watcher.name] << backend_name
      else
        log.info "synapse: restart required because we have a new backend #{watcher.name}/#{backend_name}"
        @restart_required = true
      end
    end
  end

  commands = []

  # actually enable the enabled backends, and disable the disabled ones
  cur_backends.each do |section, backends|
    backends.each do |backend, state|
      if enabled_backends.fetch(section, Set.new).include? backend
        next if state =~ /^UP/
        command = "enable server #{section}/#{backend}"
      else
        command = "disable server #{section}/#{backend}"
      end
      # Batch commands so that we don't need to re-open the connection
      # for every command.
      commands << command
    end
  end

  commands.each_slice(HAPROXY_CMD_BATCH_SIZE) do |batch|
    # actually write the command to the socket
    begin
      output = talk_to_socket(socket_file_path, batch.join(';') + "\n")
    rescue StandardError => e
      log.warn "synapse: restart required because socket command #{batch.join(';')} failed with "\
               "error #{e.inspect}"
      @restart_required = true
    else
      unless output == "\n" * batch.size
        log.warn "synapse: restart required because socket command #{batch.join(';')} failed with "\
                 "output #{output}"
        @restart_required = true
      end
    end
  end

  log.info "synapse: reconfigured haproxy via #{socket_file_path}"
end

#update_config(watchers) ⇒ Object 



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# File 'lib/synapse/config_generator/haproxy.rb', line 890

def update_config(watchers)
  # if we support updating backends, try that whenever possible
  if opts['do_socket']
    opts['socket_file_paths'].each do |socket_path|
      update_backends_at(socket_path, watchers)
    end
  else
    @restart_required = true
  end

  # generate a new config
  new_config = generate_config(watchers)

  # if we write config files, lets do that and then possibly restart
  if opts['do_writes']
    write_config(new_config)
    restart if opts['do_reloads'] && @restart_required
  end
end

#update_state_file(watchers) ⇒ Object 



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# File 'lib/synapse/config_generator/haproxy.rb', line 1321

def update_state_file(watchers)
  # if we don't support the state file, do nothing
  return if @state_file_path.nil?

  log.info "synapse: writing state file"
  timestamp = Time.now.to_i

  # Remove stale backends
  seen.each do |watcher_name, backends|
    backends.each do |backend_name, backend|
      ts = backend.fetch('timestamp', 0)
      delta = (timestamp - ts).abs
      if delta > @state_file_ttl
        log.info "synapse: expiring #{backend_name} with age #{delta}"
        backends.delete(backend_name)
      end
    end
  end

  # Remove any services which no longer have any backends
  seen.reject!{|watcher_name, backends| backends.keys.length == 0}

  # Add backends from watchers
  watchers.each do |watcher|
    seen[watcher.name] ||= {}

    watcher.backends.each do |backend|
      backend_name = construct_name(backend)
      data = {
        'timestamp' => timestamp,
      }
      server_id = @server_id_map[watcher.name][backend_name].to_i
      if server_id && server_id > 0 && server_id <= MAX_SERVER_ID
        data['haproxy_server_id'] = server_id
      end

      seen[watcher.name][backend_name] = data.merge(backend)
    end
  end

  # write the data!
  write_data_to_state_file(seen)
end

#validate_haproxy_stanza(stanza, stanza_type, service_name) ⇒ Object 



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# File 'lib/synapse/config_generator/haproxy.rb', line 1001

def validate_haproxy_stanza(stanza, stanza_type, service_name)
  return stanza.select {|setting|
    parsed_setting = setting.strip.gsub(/\s+/, ' ').downcase
    if SECTION_FIELDS[stanza_type].any? {|field| parsed_setting.start_with?(field)}
      true
    else
      log.warn "synapse: service #{service_name} contains invalid #{stanza_type} setting: '#{setting}', discarding"
      false
    end
  }
end

#write_config(new_config) ⇒ Object

writes the config



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# File 'lib/synapse/config_generator/haproxy.rb', line 1261

def write_config(new_config)
  begin
    old_config = File.read(opts['config_file_path'])
  rescue Errno::ENOENT => e
    log.info "synapse: could not open haproxy config file at #{opts['config_file_path']}"
    old_config = ""
  end

  if old_config == new_config
    return false
  else
    File.open(opts['config_file_path'],'w') {|f| f.write(new_config)}
    return true
  end
end

#write_data_to_state_file(data) ⇒ Object

we do this atomically so the state file is always consistent



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# File 'lib/synapse/config_generator/haproxy.rb', line 1375

def write_data_to_state_file(data)
  tmp_state_file_path = @state_file_path + ".tmp"
  File.write(tmp_state_file_path, JSON.pretty_generate(data))
  FileUtils.mv(tmp_state_file_path, @state_file_path)
end