summaryrefslogtreecommitdiff
path: root/lib/chef/provider/powershell_script.rb
blob: 91ce11c3377cd6a23d1c07a5e77b8eb518170b68 (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
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
#
# Author:: Adam Edwards (<adamed@opscode.com>)
# Copyright:: Copyright (c) 2013 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/platform/query_helpers'
require 'chef/provider/windows_script'

class Chef
  class Provider
    class PowershellScript < Chef::Provider::WindowsScript

      provides :powershell_script, os: "windows"

      def initialize (new_resource, run_context)
        super(new_resource, run_context, '.ps1')
        add_exit_status_wrapper
      end

      def action_run
        validate_script_syntax!
        super
      end

      def command
        basepath = is_forced_32bit ? wow64_directory : run_context.node.kernel.os_info.system_directory

        # Powershell.exe is always in "v1.0" folder (for backwards compatibility)
        interpreter_path = Chef::Util::PathHelper.join(basepath, "WindowsPowerShell", "v1.0", interpreter)

        "\"#{interpreter_path}\" #{flags} \"#{script_file.path}\""
      end

      def flags
        # Must use -File rather than -Command to launch the script
        # file created by the base class that contains the script
        # code -- otherwise, powershell.exe does not propagate the
        # error status of a failed Windows process that ran at the
        # end of the script, it gets changed to '1'.
        #
        # Nano only supports -Command
        file_or_command = Chef::Platform.windows_nano_server? ? '-Command' : '-File'
        interpreter_flags = [*default_interpreter_flags, file_or_command].join(' ')

        if ! (@new_resource.flags.nil?)
          interpreter_flags = [@new_resource.flags, interpreter_flags].join(' ')
        end

        interpreter_flags
      end

      protected

      # Process exit codes are strange with PowerShell and require
      # special handling to cover common use cases.
      def add_exit_status_wrapper
        self.code = wrapper_script
        Chef::Log.debug("powershell_script provider called with script code:\n\n#{@new_resource.code}\n")
        Chef::Log.debug("powershell_script provider will execute transformed code:\n\n#{self.code}\n")
      end

      def validate_script_syntax!
        interpreter_arguments = default_interpreter_flags.join(' ')
        Tempfile.open(['chef_powershell_script-user-code', '.ps1']) do | user_script_file |
          # Wrap the user's code in a PowerShell script block so that
          # it isn't executed. However, syntactically invalid script
          # in that block will still trigger a syntax error which is
          # exactly what we want here -- verify the syntax without
          # actually running the script.
          user_code_wrapped_in_powershell_script_block = <<-EOH
{
  #{@new_resource.code}
}
EOH
          user_script_file.puts user_code_wrapped_in_powershell_script_block

          # A .close or explicit .flush required to ensure the file is
          # written to the file system at this point, which is required since
          # the intent is to execute the code just written to it.
          user_script_file.close
          validation_command = "\"#{interpreter}\" #{interpreter_arguments} -Command #{user_script_file.path}"

          # Note that other script providers like bash allow syntax errors
          # to be suppressed by setting 'returns' to a value that the
          # interpreter would return as a status code in the syntax
          # error case. We explicitly don't do this here -- syntax
          # errors will not be suppressed, since doing so could make
          # it harder for users to detect / debug invalid scripts.

          # Therefore, the only return value for a syntactically valid
          # script is 0. If an exception is raised by shellout, this
          # means a non-zero return and thus a syntactically invalid script.

          with_os_architecture(node, architecture: new_resource.architecture) do
            shell_out!(validation_command, {returns: [0]})
          end
        end
      end

      def default_interpreter_flags
        return [] if Chef::Platform.windows_nano_server?

        # Execution policy 'Bypass' is preferable since it doesn't require
        # user input confirmation for files such as PowerShell modules
        # downloaded from the Internet. However, 'Bypass' is not supported
        # prior to PowerShell 3.0, so the fallback is 'Unrestricted'
        execution_policy = Chef::Platform.supports_powershell_execution_bypass?(run_context.node) ? 'Bypass' : 'Unrestricted'

        [
          "-NoLogo",
          "-NonInteractive",
          "-NoProfile",
          "-ExecutionPolicy #{execution_policy}",
          # Powershell will hang if STDIN is redirected
          # http://connect.microsoft.com/PowerShell/feedback/details/572313/powershell-exe-can-hang-if-stdin-is-redirected
          "-InputFormat None"
        ]
      end

      # A wrapper script is used to launch user-supplied script while
      # still obtaining useful process exit codes. Unless you
      # explicitly call exit in Powershell, the powershell.exe
      # interpreter returns only 0 for success or 1 for failure. Since
      # we'd like to get specific exit codes from executable tools run
      # with Powershell, we do some work using the automatic variables
      # $? and $LASTEXITCODE to return the process exit code of the
      # last process run in the script if it is the last command
      # executed, otherwise 0 or 1 based on whether $? is set to true
      # (success, where we return 0) or false (where we return 1).
      def wrapper_script
<<-EOH
# Chef Client wrapper for powershell_script resources

# LASTEXITCODE can be uninitialized -- make it explictly 0
# to avoid incorrect detection of failure (non-zero) codes
$global:LASTEXITCODE = 0

# Catch any exceptions -- without this, exceptions will result
# In a zero return code instead of the desired non-zero code
# that indicates a failure
trap [Exception] {write-error ($_.Exception.Message);exit 1}

# Variable state that should not be accessible to the user code
new-variable -name interpolatedexitcode -visibility private -value $#{@new_resource.convert_boolean_return}
new-variable -name chefscriptresult -visibility private

# Initialize a variable we use to capture $? inside a block
$global:lastcmdlet = $null

# Execute the user's code in a script block --
$chefscriptresult =
{
 #{@new_resource.code}

 # This assignment doesn't affect the block's return value
 $global:lastcmdlet = $?
}.invokereturnasis()

# Assume failure status of 1 -- success cases
# will have to override this
$exitstatus = 1

# If convert_boolean_return is enabled, the block's return value
# gets precedence in determining our exit status
if ($interpolatedexitcode -and $chefscriptresult -ne $null -and $chefscriptresult.gettype().name -eq 'boolean')
{
  $exitstatus = [int32](!$chefscriptresult)
}
elseif ($lastcmdlet)
{
  # Otherwise, a successful cmdlet execution defines the status
  $exitstatus = 0
}
elseif ( $LASTEXITCODE -ne $null -and $LASTEXITCODE -ne 0 )
{
  # If the cmdlet status is failed, allow the Win32 status
  # in $LASTEXITCODE to define exit status. This handles the case
  # where no cmdlets, only Win32 processes have run since $?
  # will be set to $false whenever a Win32 process returns a non-zero
  # status.
  $exitstatus = $LASTEXITCODE
}

# If this script is launched with -File, the process exit
# status of PowerShell.exe will be $exitstatus. If it was
# launched with -Command, it will be 0 if $exitstatus was 0,
# 1 (i.e. failed) otherwise.
exit $exitstatus
EOH
      end

    end
  end
end