crowbar/crowbar-ha

# Author:: Robert Choi
# Cookbook Name:: pacemaker
# Provider:: primitive
#
# Copyright:: 2013, Robert Choi
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

require "shellwords"

this_dir = ::File.dirname(__FILE__)
require ::File.expand_path("../libraries/pacemaker", this_dir)
require ::File.expand_path("../libraries/chef/mixin/pacemaker", this_dir)

include Chef::Mixin::Pacemaker::RunnableResource

action :create do
  name = new_resource.name

  if @current_resource_definition.nil?
    create_resource(name)
  else
    update_resource(name)
  end
end

action :update do
  unless @current_resource_definition.nil?
    update_resource(new_resource.name)
  end
end

action :delete do
  delete_runnable_resource
end

action :start do
  start_runnable_resource
end

action :stop do
  stop_runnable_resource
end

def cib_object_class
  ::Pacemaker::Resource::Primitive
end

def load_current_resource
  standard_load_current_resource
end

def resource_attrs
  [:agent, :params, :meta]
end

def create_resource(name)
  standard_create_resource
end

def get_cluster_op_defaults(node)
  return nil unless !node[:pacemaker].nil? && !node[:pacemaker][:op_defaults].nil?

  node[:pacemaker][:op_defaults].to_hash
end

def update_resource(name)
  current_agent = @current_resource.agent
  unless current_agent.include? ":"
    current_agent = "ocf:heartbeat:" + current_agent
  end

  new_agent = new_resource.agent
  unless new_agent.include? ":"
    new_agent = "ocf:heartbeat:" + new_agent
  end

  if current_agent != new_agent
    raise format(
      "Existing %s has agent '%s' but recipe wanted '%s'",
      @current_cib_object, @current_resource.agent, new_resource.agent
    )
  end

  maybe_modify_resource(name)
end

# Merge in op defaults from barclamp to those from pacemaker
# Returns a *single* Hash with merged ops for 'monitor'. Should 'monitor' be
# an array of hashes, it has to be dealt externally to this function.
def merge_cluster_op_monitor_defaults(op_monitor, op_defaults)
  op_defaults ||= {}
  op_defaults["monitor"] ||= {}
  op_defaults["monitor"]["on-fail"] ||= ""

  if !op_defaults["monitor"]["on-fail"].empty?
    # Merge defined 'on-fail' default with already existing ops
    default_op_monitor = { "on-fail" => op_defaults["monitor"]["on-fail"] }
    default_op_monitor.merge(op_monitor)
  else
    # 'on-fail' default not defined, return original ops
    op_monitor
  end
end

def maybe_modify_resource(name)
  deprecate_target_role

  Chef::Log.info "Checking existing #{@current_cib_object} for modifications"

  cmds = []

  # We don't want to modify data from the recipe, so ensure we have a copy as a hash
  if new_resource.op.nil?
    ops = {}
  elsif new_resource.op.is_a? Hash
    ops = new_resource.op.clone
  else
    ops = new_resource.op.to_hash
  end

  cluster_op_defaults = get_cluster_op_defaults(node)

  ops["monitor"] ||= {}

  # The ops["monitor"] section is presented in two flavors:
  # - Single op value: Hash
  # - Multiple op values (i.e. for master vs slave): Array of Hashes
  if ops["monitor"].is_a?(Array)
    ops["monitor"].map! do |op_monitor|
      merge_cluster_op_monitor_defaults(op_monitor, cluster_op_defaults)
    end
  elsif ops["monitor"].is_a?(Hash)
    ops["monitor"] = merge_cluster_op_monitor_defaults(ops["monitor"], cluster_op_defaults)
  end

  new_resource.op(ops)

  desired_primitive = cib_object_class.from_chef_resource(new_resource)

  # We deprecated setting target-role values via the meta attribute, in favor
  # of :start/:stop actions on the resource. So this should not be relied upon
  # anymore, and it's safe to drop this if we want to.
  #
  # There is one racy case where this matters:
  #   - node1 and node2 try to create a primitive with the chef resource;
  #     on initial creation, we set target-role='Stopped' because we do not
  #     want to autostart primitives.
  #   - because they can't create it at the same time, node2 will fail on
  #     creation. If the chef resource is configured to retry, then node2 will
  #     then try to update the primitive (since it now exists); but the chef
  #     resource is not reloaded so still has target-role='Stopped'.
  #   - if node1 had also started the primitive before node2 retries the
  #     :create, then the target-role will be changed from 'Started' to
  #     'Stopped' with the update.
  #
  # This can result in a primitive not being started with [:create, :start].
  # Therefore, we just delete this deprecated bit from meta to avoid any issue.
  new_resource.meta.delete("target-role")
  desired_primitive.meta.delete("target-role")

  if desired_primitive.op_string != @current_cib_object.op_string
    Chef::Log.debug "op changed from [#{@current_cib_object.op_string}] to [#{desired_primitive.op_string}]"
    cmds = [desired_primitive.reconfigure_command]
  else
    maybe_configure_params(name, cmds, :params)
    maybe_configure_params(name, cmds, :meta)
  end

  cmds.each do |cmd|
    execute cmd do
      action :nothing
    end.run_action(:run)
  end

  new_resource.updated_by_last_action(true) unless cmds.empty?
end

def maybe_configure_params(name, cmds, data_type)
  configure_cmd_prefix = "crm_resource --resource #{name}"

  new_resource.send(data_type).each do |param, new_value|
    current_value = @current_resource.send(data_type)[param]
    # Value from recipe might be a TrueClass instance, but the same
    # value would be retrieved from the cluster resource as the String
    # "true".  So we force a string-wise comparison to adhere to
    # Postel's Law whilst minimising activity on the Chef client node.
    if current_value.to_s == new_value.to_s
      Chef::Log.info("#{name}'s #{param} #{data_type} didn't change")
    else
      Chef::Log.info("#{name}'s #{param} #{data_type} changed from #{current_value} to #{new_value}")
      cmd = configure_cmd_prefix +
        %' --set-parameter #{Shellwords.escape param}' +
        %' --parameter-value #{Shellwords.escape new_value}'
      cmd += " --meta" if data_type == :meta
      cmds << cmd
    end
  end

  @current_resource.send(data_type).each do |param, value|
    unless new_resource.send(data_type).key? param
      Chef::Log.info("#{name}'s #{param} #{data_type} was removed")
      cmd = configure_cmd_prefix + \
        %' --delete-parameter #{Shellwords.escape param}'
      cmd += " --meta" if data_type == :meta
      cmds << cmd
    end
  end
end