summaryrefslogtreecommitdiff
path: root/lib/chef/provider/link.rb
blob: a5f9b0bb29ee01deefd64e7b20f91f386a56fba2 (plain)
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
#
# Author:: Adam Jacob (<adam@opscode.com>)
# Copyright:: Copyright (c) 2008 Opscode, 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/config'
require 'chef/log'
require 'chef/mixin/file_class'
require 'chef/resource/link'
require 'chef/provider'
require 'chef/scan_access_control'
require 'chef/util/path_helper'

class Chef
  class Provider
    class Link < Chef::Provider

      provides :link

      include Chef::Mixin::EnforceOwnershipAndPermissions
      include Chef::Mixin::FileClass

      def negative_complement(big)
        if big > 1073741823 # Fixnum max
          big -= (2**32) # diminished radix wrap to negative
        end
        big
      end

      private :negative_complement

      def whyrun_supported?
        true
      end

      def load_current_resource
        @current_resource = Chef::Resource::Link.new(@new_resource.name)
        @current_resource.target_file(@new_resource.target_file)
        if file_class.symlink?(@current_resource.target_file)
          @current_resource.link_type(:symbolic)
          @current_resource.to(
            canonicalize(file_class.readlink(@current_resource.target_file))
          )
        else
          @current_resource.link_type(:hard)
          if ::File.exists?(@current_resource.target_file)
            if ::File.exists?(@new_resource.to) &&
               file_class.stat(@current_resource.target_file).ino ==
               file_class.stat(@new_resource.to).ino
              @current_resource.to(canonicalize(@new_resource.to))
            else
              @current_resource.to("")
            end
          end
        end
        ScanAccessControl.new(@new_resource, @current_resource).set_all!
        @current_resource
      end

      def define_resource_requirements
        requirements.assert(:delete) do |a|
          a.assertion do
            if @current_resource.to
              @current_resource.link_type == @new_resource.link_type and
              (@current_resource.link_type == :symbolic  or @current_resource.to != '')
            else
              true
            end
          end
          a.failure_message Chef::Exceptions::Link, "Cannot delete #{@new_resource} at #{@new_resource.target_file}! Not a #{@new_resource.link_type} link."
          a.whyrun("Would assume the link at #{@new_resource.target_file} was previously created")
        end
      end

      def canonicalize(path)
        Chef::Platform.windows? ? path.gsub('/', '\\') : path
      end

      def action_create
        # current_resource is the symlink that currently exists
        # new_resource is the symlink we need to create
        #   to - the location to link to
        #   target_file - the name of the link

        if @current_resource.to != canonicalize(@new_resource.to) ||
           @current_resource.link_type != @new_resource.link_type
          # Handle the case where the symlink already exists and is pointing at a valid to_file
          if @current_resource.to
            # On Windows, to fix a symlink already pointing at a directory we must first
            # ::Dir.unlink the symlink (not the directory), while if we have a symlink
            # pointing at file we must use ::File.unlink on the symlink.
            # However if the new symlink will point to a file and the current symlink is pointing at a
            # directory we want to throw an exception and calling ::File.unlink on the directory symlink
            # will throw the correct ones.
            if Chef::Platform.windows? && ::File.directory?(@new_resource.to) &&
               ::File.directory?(@current_resource.target_file)
              converge_by("unlink existing windows symlink to dir at #{@new_resource.target_file}") do
                ::Dir.unlink(@new_resource.target_file)
              end
            else
              converge_by("unlink existing symlink to file at #{@new_resource.target_file}") do
                ::File.unlink(@new_resource.target_file)
              end
            end
          end
          if @new_resource.link_type == :symbolic
            converge_by("create symlink at #{@new_resource.target_file} to #{@new_resource.to}") do
              file_class.symlink(canonicalize(@new_resource.to),@new_resource.target_file)
              Chef::Log.debug("#{@new_resource} created #{@new_resource.link_type} link from #{@new_resource.target_file} -> #{@new_resource.to}")
              Chef::Log.info("#{@new_resource} created")
            end
          elsif @new_resource.link_type == :hard
            converge_by("create hard link at #{@new_resource.target_file} to #{@new_resource.to}") do
              file_class.link(@new_resource.to, @new_resource.target_file)
              Chef::Log.debug("#{@new_resource} created #{@new_resource.link_type} link from #{@new_resource.target_file} -> #{@new_resource.to}")
              Chef::Log.info("#{@new_resource} created")
            end
          end
        end
        if @new_resource.link_type == :symbolic
          if access_controls.requires_changes?
            converge_by(access_controls.describe_changes) do
              access_controls.set_all
            end
          end
        end
      end

      def action_delete
        if @current_resource.to # Exists
          converge_by("delete link at #{@new_resource.target_file}") do
            ::File.delete(@new_resource.target_file)
            Chef::Log.info("#{@new_resource} deleted")
          end
        end
      end

      # Implementation components *should not* follow symlinks when managing
      # access control (e.g., use lchmod instead of chmod) if the resource is a
      # symlink.
      def manage_symlink_access?
        @new_resource.link_type == :symbolic
      end
    end
  end
end