1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
|
# An actual fact resolution mechanism. These are largely just chunks of
# code, with optional confinements restricting the mechanisms to only working on
# specific systems. Note that the confinements are always ANDed, so any
# confinements specified must all be true for the resolution to be
# suitable.
require 'facter/util/confine'
require 'timeout'
require 'rbconfig'
class Facter::Util::Resolution
attr_accessor :interpreter, :code, :name, :timeout
WINDOWS = Config::CONFIG['host_os'] =~ /mswin|win32|dos|mingw|cygwin/i
INTERPRETER = WINDOWS ? 'cmd.exe' : '/bin/sh'
def self.have_which
if ! defined?(@have_which) or @have_which.nil?
if Facter.value(:kernel) == 'windows'
@have_which = false
else
%x{which which >/dev/null 2>&1}
@have_which = ($? == 0)
end
end
@have_which
end
# Execute a program and return the output of that program.
#
# Returns nil if the program can't be found, or if there is a problem
# executing the code.
#
def self.exec(code, interpreter = INTERPRETER)
raise ArgumentError, "invalid interpreter" unless interpreter == INTERPRETER
# Try to guess whether the specified code can be executed by looking at the
# first word. If it cannot be found on the PATH defer on resolving the fact
# by returning nil.
# This only fails on shell built-ins, most of which are masked by stuff in
# /bin or of dubious value anyways. In the worst case, "sh -c 'builtin'" can
# be used to work around this limitation
#
# Windows' %x{} throws Errno::ENOENT when the command is not found, so we
# can skip the check there. This is good, since builtins cannot be found
# elsewhere.
if have_which and !WINDOWS
path = nil
binary = code.split.first
if code =~ /^\//
path = binary
else
path = %x{which #{binary} 2>/dev/null}.chomp
# we don't have the binary necessary
return nil if path == "" or path.match(/Command not found\./)
end
return nil unless FileTest.exists?(path)
end
out = nil
begin
out = %x{#{code}}.chomp
rescue Errno::ENOENT => detail
# command not found on Windows
return nil
rescue => detail
$stderr.puts detail
return nil
end
if out == ""
return nil
else
return out
end
end
# Add a new confine to the resolution mechanism.
def confine(confines)
confines.each do |fact, values|
@confines.push Facter::Util::Confine.new(fact, *values)
end
end
def has_weight(weight)
@weight = weight
end
# Create a new resolution mechanism.
def initialize(name)
@name = name
@confines = []
@value = nil
@timeout = 0
@weight = nil
end
# Return the importance of this resolution.
def weight
if @weight
@weight
else
@confines.length
end
end
# We need this as a getter for 'timeout', because some versions
# of ruby seem to already have a 'timeout' method and we can't
# seem to override the instance methods, somehow.
def limit
@timeout
end
# Set our code for returning a value.
def setcode(string = nil, interp = nil, &block)
if string
@code = string
@interpreter = interp || INTERPRETER
else
unless block_given?
raise ArgumentError, "You must pass either code or a block"
end
@code = block
end
end
# Is this resolution mechanism suitable on the system in question?
def suitable?
unless defined? @suitable
@suitable = ! @confines.detect { |confine| ! confine.true? }
end
return @suitable
end
def to_s
return self.value()
end
# How we get a value for our resolution mechanism.
def value
result = nil
return result if @code == nil and @interpreter == nil
starttime = Time.now.to_f
begin
Timeout.timeout(limit) do
if @code.is_a?(Proc)
result = @code.call()
else
result = Facter::Util::Resolution.exec(@code,@interpreter)
end
end
rescue Timeout::Error => detail
warn "Timed out seeking value for %s" % self.name
# This call avoids zombies -- basically, create a thread that will
# dezombify all of the child processes that we're ignoring because
# of the timeout.
Thread.new { Process.waitall }
return nil
rescue => details
warn "Could not retrieve %s: %s" % [self.name, details]
return nil
end
finishtime = Time.now.to_f
ms = (finishtime - starttime) * 1000
Facter.show_time "#{self.name}: #{"%.2f" % ms}ms"
return nil if result == ""
return result
end
end
|
