Merge pull request #9321 from chef/sysctl_v2

Add an introduced field to sysctl and expand testing

3 files changed, 82 insertions, 42 deletions

diff --git a/RELEASE_NOTES.md b/RELEASE_NOTES.md
index 9fc5a17bdb..e1a634addd 100644
--- a/RELEASE_NOTES.md
+++ b/RELEASE_NOTES.md
@@ -1,5 +1,41 @@
 This file holds "in progress" release notes for the current release under development and is intended for consumption by the Chef Documentation team. Please see <https://docs.chef.io/release_notes.html> for the official Chef release notes.
 
+# UNRELEASED
+
+### sysctl now accepts a comments parameter
+
+The `sysctl` resource has been updated to allow the inclusion of descriptive comments. Comments may be passed as an array or as a string. Any comments provided are prefixed with '#' signs and precede the `sysctl` setting in generated files.
+
+An example:
+
+```ruby
+sysctl 'vm.swappiness' do
+  value 10
+  comment [
+     "define how aggressively the kernel will swap memory pages.",
+     "Higher values will increase aggressiveness",
+     "lower values decrease the amount of swap.",
+     "A value of 0 instructs the kernel not to initiate swap",
+     "until the amount of free and file-backed pages is less",
+     "than the high water mark in a zone.",
+     "The default value is 60."
+    ]
+end
+```
+
+which results in `/etc/sysctl.d/99-chef-vm.swappiness.conf` as follows:
+
+```
+# define how aggressively the kernel will swap memory pages.
+# Higher values will increase aggressiveness
+# lower values decrease the amount of swap.
+# A value of 0 instructs the kernel not to initiate swap
+# until the amount of free and file-backed pages is less
+# than the high water mark in a zone.
+# The default value is 60.
+vm.swappiness = 10
+```
+
 # Chef Infra Client 15.7
 
 ## Updated Resources
@@ -568,39 +604,6 @@ Our underlying SSH implementation has been updated to support the new ed25519 SS
 
 Chef Solo's `--delete-entire-chef-repo` option has been extended to work in Local Mode as well. Be warned that this flag does exactly what it states, and when used incorrectly, can result in loss of work.
 
-### sysctl now accepts a comments parameter
-
-The `sysctl` resource has been updated to allow the inclusion of descriptive comments. Comments may be passed as an array or a string. Any comments provided are prefixed with '#' signs and precede the `sysctl` setting in generated files.
-
-An example:
-
-```
-sysctl 'vm.swappiness' do
-  value 10
-  comment [
-     "define how aggressively the kernel will swap memory pages.",
-     "Higher values will increase aggressiveness",
-     "lower values decrease the amount of swap.",
-     "A value of 0 instructs the kernel not to initiate swap",
-     "until the amount of free and file-backed pages is less",
-     "than the high water mark in a zone.",
-     "The default value is 60."
-    ]
-end
-```
-
-which results in `/etc/sysctl.d/99-chef-vm.swappiness.conf` as follows
-```
-# define how aggressively the kernel will swap memory pages.
-# Higher values will increase aggressiveness
-# lower values decrease the amount of swap.
-# A value of 0 instructs the kernel not to initiate swap
-# until the amount of free and file-backed pages is less
-# than the high water mark in a zone.
-# The default value is 60.
-vm.swappiness = 10
-```
-
 ## New Resources
 
 ### archive_file resource
diff --git a/lib/chef/resource/sysctl.rb b/lib/chef/resource/sysctl.rb
index af1df9746c..edbeb23daa 100644
--- a/lib/chef/resource/sysctl.rb
+++ b/lib/chef/resource/sysctl.rb
@@ -1,6 +1,6 @@
 #
 # Copyright:: 2018, Webb Agile Solutions Ltd.
-# Copyright:: 2018-2018, Chef Software Inc.
+# Copyright:: 2018-2020, Chef Software Inc.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -47,7 +47,8 @@ class Chef
 
       property :comment, [Array, String],
         description: "Comments, placed above the resource setting in the generated file. For multi-line comments, use an array of strings, one per line.",
-        default: []
+        default: [],
+        introduced: "15.8"
 
       property :conf_dir, String,
         description: "The configuration directory to write the config to.",
@@ -84,13 +85,8 @@ class Chef
 
           directory new_resource.conf_dir
 
-          # construct a string, joining members of new_resource.comment
-          sysctl_lines = Array(new_resource.comment).map { |c| "# #{c.strip}" }
-
-          sysctl_lines << "#{new_resource.key} = #{new_resource.value}"
-
           file "#{new_resource.conf_dir}/99-chef-#{new_resource.key.tr("/", ".")}.conf" do
-            content sysctl_lines.join("\n")
+            content contruct_sysctl_content
           end
 
           execute "Load sysctl values" do
@@ -121,9 +117,28 @@ class Chef
       end
 
       action_class do
+        #
+        # Shell out to set the sysctl value
+        #
+        # @param [String] key The sysctl key
+        # @param [String] value The value of the sysctl key
+        #
         def set_sysctl_param(key, value)
           shell_out!("sysctl #{"-e " if new_resource.ignore_error}-w \"#{key}=#{value}\"")
         end
+
+        #
+        # construct a string, joining members of new_resource.comment and new_resource.value
+        #
+        # @return [String] The text file content
+        #
+        def contruct_sysctl_content
+          sysctl_lines = Array(new_resource.comment).map { |c| "# #{c.strip}" }
+
+          sysctl_lines << "#{new_resource.key} = #{new_resource.value}"
+
+          sysctl_lines.join("\n")
+        end
       end
 
       private
diff --git a/spec/unit/resource/sysctl_spec.rb b/spec/unit/resource/sysctl_spec.rb
index ba4b23f098..5d978d3b38 100644
--- a/spec/unit/resource/sysctl_spec.rb
+++ b/spec/unit/resource/sysctl_spec.rb
@@ -1,5 +1,5 @@
 #
-# Copyright:: Copyright 2018, Chef Software, Inc.
+# Copyright:: Copyright 2018-2020, Chef Software, Inc.
 # License:: Apache License, Version 2.0
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -19,6 +19,7 @@ require "spec_helper"
 
 describe Chef::Resource::Sysctl do
   let(:resource) { Chef::Resource::Sysctl.new("fakey_fakerton") }
+  let(:provider) { resource.provider_for_action(:create) }
 
   it "sets resource name as :sysctl" do
     expect(resource.resource_name).to eql(:sysctl)
@@ -51,4 +52,25 @@ describe Chef::Resource::Sysctl do
     resource.value 1.1
     expect(resource.value).to eql("1.1")
   end
+
+  context "#contruct_sysctl_content" do
+    before do
+      resource.key("foo")
+      resource.value("bar")
+    end
+
+    context "when comment is a String" do
+      it "Returns content for use with a file resource" do
+        resource.comment("This sets foo / bar on our system")
+        expect(provider.contruct_sysctl_content).to eql("# This sets foo / bar on our system\nfoo = bar")
+      end
+    end
+
+    context "when comment is an Array" do
+      it "Returns content for use with a file resource" do
+        resource.comment(["This sets foo / bar on our system", "We need for baz"])
+        expect(provider.contruct_sysctl_content).to eql("# This sets foo / bar on our system\n# We need for baz\nfoo = bar")
+      end
+    end
+  end
 end