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Viewing File: platform_introspection.rb
#
# Author:: Adam Jacob (<adam@chef.io>)
# Copyright:: Copyright (c) Chef Software Inc.
# License:: Apache License, Version 2.0
#
# 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 "chef-utils" unless defined?(ChefUtils::CANARY)
require "chef/mixin/chef_utils_wiring" unless defined?(Chef::Mixin::ChefUtilsWiring)
class Chef
module DSL
# == Chef::DSL::PlatformIntrospection
# Provides the DSL for platform-dependent switch logic, such as
# #value_for_platform.
module PlatformIntrospection
include ChefUtils
include Chef::Mixin::ChefUtilsWiring
# Implementation class for determining platform dependent values
class PlatformDependentValue
# Create a platform dependent value object.
# === Arguments
# platform_hash (Hash) a hash of the same structure as Chef::Platform,
# like this:
# {
# :debian => {:default => 'the value for all debian'}
# [:centos, :redhat, :fedora] => {:default => "value for all EL variants"}
# :ubuntu => { :default => "default for ubuntu", '10.04' => "value for 10.04 only"},
# :default => "the default when nothing else matches"
# }
# * platforms can be specified as Symbols or Strings
# * multiple platforms can be grouped by using an Array as the key
# * values for platforms need to be Hashes of the form:
# {platform_version => value_for_that_version}
# * the exception to the above is the default value, which is given as
# :default => default_value
def initialize(platform_hash)
@values = {}
platform_hash.each { |platforms, value| set(platforms, value) }
end
def value_for_node(node)
platform, version = node[:platform].to_s, node[:platform_version].to_s
# Check if we match a version constraint via Chef::VersionConstraint::Platform and Chef::Version::Platform
matched_value = match_versions(node)
if @values.key?(platform) && @values[platform].key?(version)
@values[platform][version]
elsif matched_value
matched_value
elsif @values.key?(platform) && @values[platform].key?("default")
@values[platform]["default"]
elsif @values.key?("default")
@values["default"]
else
nil
end
end
private
def match_versions(node)
platform, version = node[:platform].to_s, node[:platform_version].to_s
return nil unless @values.key?(platform)
node_version = Chef::Version::Platform.new(version)
key_matches = []
keys = @values[platform].keys
keys.each do |k|
begin
if Chef::VersionConstraint::Platform.new(k).include?(node_version)
key_matches << k
end
rescue Chef::Exceptions::InvalidVersionConstraint => e
Chef::Log.trace "Caught InvalidVersionConstraint. This means that a key in value_for_platform cannot be interpreted as a Chef::VersionConstraint::Platform."
Chef::Log.trace(e)
end
end
return @values[platform][version] if key_matches.include?(version)
case key_matches.length
when 0
nil
when 1
@values[platform][key_matches.first]
else
raise "Multiple matches detected for #{platform} with values #{@values}. The matches are: #{key_matches}"
end
rescue Chef::Exceptions::InvalidCookbookVersion => e
# Lets not break because someone passes a weird string like 'default' :)
Chef::Log.trace(e)
Chef::Log.trace "InvalidCookbookVersion exceptions are common and expected here: the generic constraint matcher attempted to match something which is not a constraint. Moving on to next version or constraint"
nil
rescue Chef::Exceptions::InvalidPlatformVersion => e
Chef::Log.trace "Caught InvalidPlatformVersion, this means that Chef::Version::Platform does not know how to turn #{node_version} into an x.y.z format"
Chef::Log.trace(e)
nil
end
def set(platforms, value)
if platforms.to_s == "default"
@values["default"] = value
else
assert_valid_platform_values!(platforms, value)
Array(platforms).each { |platform| @values[platform.to_s] = normalize_keys(value) }
value
end
end
def normalize_keys(hash)
hash.inject({}) do |h, key_value|
keys, value = *key_value
Array(keys).each do |key|
h[key.to_s] = value
end
h
end
end
def assert_valid_platform_values!(platforms, value)
unless value.is_a?(Hash)
msg = "platform dependent values must be specified in the format :platform => {:version => value} "
msg << "you gave a value #{value.inspect} for platform(s) #{platforms}"
raise ArgumentError, msg
end
end
end
# Given a hash similar to the one we use for Platforms, select a value from the hash. Supports
# per platform defaults, along with a single base default. Arrays may be passed as hash keys and
# will be expanded.
#
# === Parameters
# platform_hash:: A platform-style hash.
#
# === Returns
# value:: Whatever the most specific value of the hash is.
def value_for_platform(platform_hash)
PlatformDependentValue.new(platform_hash).value_for_node(node)
end
# Given a list of platforms, returns true if the current recipe is being run on a node with
# that platform, false otherwise.
#
# === Parameters
# args:: A list of platforms. Each platform can be in string or symbol format.
#
# === Returns
# true:: If the current platform is in the list
# false:: If the current platform is not in the list
def platform?(*args)
has_platform = false
args.flatten.each do |platform|
has_platform = true if platform.to_s == node[:platform]
end
has_platform
end
# Implementation class for determining platform family dependent values
class PlatformFamilyDependentValue
# Create a platform family dependent value object.
# === Arguments
# platform_family_hash (Hash) a map of platform families to values.
# like this:
# {
# :rhel => "value for all EL variants"
# :fedora => "value for fedora variants fedora and amazon" ,
# [:fedora, :rhel] => "value for all known redhat variants"
# :debian => "value for debian variants including debian, ubuntu, mint" ,
# :default => "the default when nothing else matches"
# }
# * platform families can be specified as Symbols or Strings
# * multiple platform families can be grouped by using an Array as the key
# * values for platform families can be any object, with no restrictions. Some examples:
# - [:stop, :start]
# - "mysql-devel"
# - { :key => "value" }
def initialize(platform_family_hash)
@values = {}
@values["default"] = nil
platform_family_hash.each { |platform_families, value| set(platform_families, value) }
end
def value_for_node(node)
if node.key?(:platform_family)
platform_family = node[:platform_family].to_s
if @values.key?(platform_family)
@values[platform_family]
else
@values["default"]
end
else
@values["default"]
end
end
private
def set(platform_family, value)
if platform_family.to_s == "default"
@values["default"] = value
else
Array(platform_family).each { |family| @values[family.to_s] = value }
value
end
end
end
# Given a hash mapping platform families to values, select a value from the hash. Supports a single
# base default if platform family is not in the map. Arrays may be passed as hash keys and will be
# expanded
#
# === Parameters
# platform_family_hash:: A hash in the form { platform_family_name => value }
#
# === Returns
# value:: Whatever the most specific value of the hash is.
def value_for_platform_family(platform_family_hash)
PlatformFamilyDependentValue.new(platform_family_hash).value_for_node(node)
end
# Given a list of platform families, returns true if the current recipe is being run on a
# node within that platform family, false otherwise.
#
# === Parameters
# args:: A list of platform families. Each platform family can be in string or symbol format.
#
# === Returns
# true:: if the current node platform family is in the list.
# false:: if the current node platform family is not in the list.
def platform_family?(*args)
args.flatten.any? do |platform_family|
platform_family.to_s == node[:platform_family]
end
end
# a simple helper to determine if we're on a windows release pre-2012 / 8
#
# @deprecated Windows releases before Windows 2012 and 8 are no longer supported
# @return [Boolean] Is the system older than Windows 8 / 2012
def older_than_win_2012_or_8?(node = run_context.nil? ? nil : run_context.node)
false # we don't support platforms that would be true
end
# ^^^^^^ NOTE: PLEASE DO NOT CONTINUE TO ADD THESE KINDS OF PLATFORM_VERSION APIS WITHOUT ^^^^^^^
# ^^^^^^ GOING THROUGH THE DESIGN REVIEW PROCESS AND ADDRESS THE EXISTING CHEF-SUGAR ONES ^^^^^^^
# ^^^^^^ DO "THE HARD RIGHT THING" AND ADDRESS THE BROADER PROBLEM AND FIX IT ALL. ^^^^^^^
end
end
end