Add hostname resource from chef_hostname cookbook

Add in a new resource for managing hostnames

Signed-off-by: Tim Smith <tsmith@chef.io>

3 files changed, 273 insertions, 0 deletions

diff --git a/lib/chef/resource/hostname.rb b/lib/chef/resource/hostname.rb
new file mode 100644
index 0000000000..d7fed09b8c
--- /dev/null
+++ b/lib/chef/resource/hostname.rb
@@ -0,0 +1,229 @@
+class Chef
+  class Resource
+    # Sets the hostname and updates /etc/hosts on *nix systems
+    # @since 14.0.0
+    class Hostname < Chef::Resource
+      provides :hostname
+      resource_name :hostname
+
+      property :hostname, String, name_property: true
+      property :compile_time, [ true, false ], default: true
+      property :ipaddress, [ String, nil ], default: lazy { node["ipaddress"] }
+      property :aliases, [ Array, nil ], default: nil
+      property :windows_reboot, [ true, false ], default: true
+
+      default_action :set
+
+      action_class do
+        def append_replacing_matching_lines(path, regex, string)
+          text = IO.read(path).split("\n")
+          text.reject! { |s| s =~ regex }
+          text += [ string ]
+          file path do
+            content text.join("\n") + "\n"
+            owner "root"
+            group node["root_group"]
+            mode "0644"
+            not_if { IO.read(path).split("\n").include?(string) }
+          end
+        end
+
+        # read in the xml file used by Ec2ConfigService and update the Ec2SetComputerName
+        # setting to disable updating the computer name so we don't revert our change on reboot
+        # @return [String]
+        def updated_ec2_config_xml
+          begin
+            require "nokogiri"
+            config_file = 'C:\Program Files\Amazon\Ec2ConfigService\Settings\config.xml'
+            config = ::Nokogiri::XML(::File.read(config_file))
+            # find an element named State with a sibling element whose value is Ec2SetComputerName
+            setting = config.at_xpath("//Plugin/State[../Name/text() = 'Ec2SetComputerName']")
+            setting.content = "Disabled"
+          rescue
+            return ""
+          end
+          config.to_s
+        end
+      end
+
+      action :set do
+        ohai "reload hostname" do
+          plugin "hostname"
+          action :nothing
+        end
+
+        if node["platform_family"] != "windows"
+          # set the hostname via /bin/hostname
+          declare_resource(:execute, "set hostname to #{new_resource.hostname}") do
+            command "/bin/hostname #{new_resource.hostname}"
+            not_if { shell_out!("hostname").stdout.chomp == new_resource.hostname }
+            notifies :reload, "ohai[reload hostname]"
+          end
+
+          # make sure node['fqdn'] resolves via /etc/hosts
+          unless new_resource.ipaddress.nil?
+            newline = "#{new_resource.ipaddress} #{new_resource.hostname}"
+            newline << " #{new_resource.aliases.join(" ")}" if new_resource.aliases && !new_resource.aliases.empty?
+            newline << " #{new_resource.hostname[/[^\.]*/]}"
+            r = append_replacing_matching_lines("/etc/hosts", /^#{new_resource.ipaddress}\s+|\s+#{new_resource.hostname}\s+/, newline)
+            r.atomic_update false if docker?
+            r.notifies :reload, "ohai[reload hostname]"
+          end
+
+          # setup the hostname to perist on a reboot
+          case
+          when ::File.exist?("/usr/sbin/scutil")
+            # darwin
+            declare_resource(:execute, "set HostName via scutil") do
+              command "/usr/sbin/scutil --set HostName #{new_resource.hostname}"
+              not_if { shell_out!("/usr/sbin/scutil --get HostName").stdout.chomp == new_resource.hostname }
+              notifies :reload, "ohai[reload hostname]"
+            end
+            declare_resource(:execute, "set ComputerName via scutil") do
+              command "/usr/sbin/scutil --set ComputerName  #{new_resource.hostname}"
+              not_if { shell_out!("/usr/sbin/scutil --get ComputerName").stdout.chomp == new_resource.hostname }
+              notifies :reload, "ohai[reload hostname]"
+            end
+            shortname = new_resource.hostname[/[^\.]*/]
+            declare_resource(:execute, "set LocalHostName via scutil") do
+              command "/usr/sbin/scutil --set LocalHostName #{shortname}"
+              not_if { shell_out!("/usr/sbin/scutil --get LocalHostName").stdout.chomp == shortname }
+              notifies :reload, "ohai[reload hostname]"
+            end
+          when node["os"] == "linux"
+            case
+            when ::File.exist?("/usr/bin/hostnamectl") && !docker?
+              # use hostnamectl whenever we find it on linux (as systemd takes over the world)
+              # this must come before other methods like /etc/hostname and /etc/sysconfig/network
+              declare_resource(:execute, "hostnamectl set-hostname #{new_resource.hostname}") do
+                notifies :reload, "ohai[reload hostname]"
+                not_if { shell_out!("hostnamectl status", { :returns => [0, 1] }).stdout =~ /Static hostname:\s+#{new_resource.hostname}/ }
+              end
+            when ::File.exist?("/etc/hostname")
+              # debian family uses /etc/hostname
+              # arch also uses /etc/hostname
+              # the "platform: iox_xr, platform_family: wrlinux, os: linux" platform also hits this
+              # the "platform: nexus, platform_family: wrlinux, os: linux" platform also hits this
+              # this is also fallback for any linux systemd host in a docker container (where /usr/bin/hostnamectl will fail)
+              declare_resource(:file, "/etc/hostname") do
+                atomic_update false if docker?
+                content "#{new_resource.hostname}\n"
+                owner "root"
+                group node["root_group"]
+                mode "0644"
+              end
+            when ::File.file?("/etc/sysconfig/network")
+              # older non-systemd RHEL/Fedora derived
+              append_replacing_matching_lines("/etc/sysconfig/network", /^HOSTNAME\s*=/, "HOSTNAME=#{new_resource.hostname}")
+            when ::File.exist?("/etc/HOSTNAME")
+              # SuSE/OpenSUSE uses /etc/HOSTNAME
+              declare_resource(:file, "/etc/HOSTNAME") do
+                content "#{new_resource.hostname}\n"
+                owner "root"
+                group node["root_group"]
+                mode "0644"
+              end
+            when ::File.exist?("/etc/conf.d/hostname")
+              # Gentoo
+              declare_resource(:file, "/etc/conf.d/hostname") do
+                content "hostname=\"#{new_resource.hostname}\"\n"
+                owner "root"
+                group node["root_group"]
+                mode "0644"
+              end
+            else
+              # This is a failsafe for all other linux distributions where we set the hostname
+              # via /etc/sysctl.conf on reboot.  This may get into a fight with other cookbooks
+              # that manage sysctls on linux.
+              append_replacing_matching_lines("/etc/sysctl.conf", /^\s+kernel\.hostname\s+=/, "kernel.hostname=#{new_resource.hostname}")
+            end
+          when ::File.exist?("/etc/rc.conf")
+            # *BSD systems with /etc/rc.conf + /etc/myname
+            append_replacing_matching_lines("/etc/rc.conf", /^\s+hostname\s+=/, "hostname=#{new_resource.hostname}")
+
+            declare_resource(:file, "/etc/myname") do
+              content "#{new_resource.hostname}\n"
+              owner "root"
+              group node["root_group"]
+              mode "0644"
+            end
+          when ::File.exist?("/etc/nodename")
+            # Solaris <= 5.10 systems prior to svccfg taking over this functionality (must come before svccfg handling)
+            declare_resource(:file, "/etc/nodename") do
+              content "#{new_resource.hostname}\n"
+              owner "root"
+              group node["root_group"]
+              mode "0644"
+            end
+            # Solaris also has /etc/inet/hosts (copypasta alert)
+            unless new_resource.ipaddress.nil?
+              newline = "#{new_resource.ipaddress} #{new_resource.hostname}"
+              newline << " #{new_resource.aliases.join(" ")}" if new_resource.aliases && !new_resource.aliases.empty?
+              newline << " #{new_resource.hostname[/[^\.]*/]}"
+              r = append_replacing_matching_lines("/etc/inet/hosts", /^#{new_resource.ipaddress}\s+|\s+#{new_resource.hostname}\s+/, newline)
+              r.notifies :reload, "ohai[reload hostname]"
+            end
+          when ::File.exist?("/usr/sbin/svccfg")
+            # Solaris >= 5.11 systems using svccfg (must come after /etc/nodename handling)
+            declare_resource(:execute, "svccfg -s system/identity:node setprop config/nodename=\'#{new_resource.hostname}\'") do
+              notifies :run, "execute[svcadm refresh]", :immediately
+              notifies :run, "execute[svcadm restart]", :immediately
+              not_if { shell_out!("svccfg -s system/identity:node listprop config/nodename").stdout.chomp =~ /config\/nodename\s+astring\s+#{new_resource.hostname}/ }
+            end
+            declare_resource(:execute, "svcadm refresh") do
+              command "svcadm refresh system/identity:node"
+              action :nothing
+            end
+            declare_resource(:execute, "svcadm restart") do
+              command "svcadm restart system/identity:node"
+              action :nothing
+            end
+          else
+            raise "Do not know how to set hostname on os #{node["os"]}, platform #{node["platform"]},"\
+              "platform_version #{node["platform_version"]}, platform_family #{node["platform_family"]}"
+          end
+
+        else # windows
+
+        # suppress EC2 config service from setting our hostname
+          if ::File.exist?('C:\Program Files\Amazon\Ec2ConfigService\Settings\config.xml')
+            xml_contents = updated_ec2_config_xml
+            if xml_contents.empty?
+              Chef::Log.warn('Unable to properly parse and update C:\Program Files\Amazon\Ec2ConfigService\Settings\config.xml contents. Skipping file update.')
+            else
+              declare_resource(:file, 'C:\Program Files\Amazon\Ec2ConfigService\Settings\config.xml') do
+                content xml_contents
+              end
+            end
+          end
+
+          # update via netdom
+          declare_resource(:powershell_script, "set hostname") do
+            code <<-EOH
+              $sysInfo = Get-WmiObject -Class Win32_ComputerSystem
+              $sysInfo.Rename("#{new_resource.hostname}")
+            EOH
+            notifies :request_reboot, "reboot[setting hostname]"
+            not_if { Socket.gethostbyname(Socket.gethostname).first == new_resource.hostname }
+          end
+
+          # reboot because $windows
+          declare_resource(:reboot, "setting hostname") do
+            reason "chef setting hostname"
+            action :nothing
+            only_if { new_resource.windows_reboot }
+          end
+        end
+      end
+
+      # this resource forces itself to run at compile_time
+      def after_created
+        if compile_time
+          Array(action).each do |action|
+            run_action(action)
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/chef/resources.rb b/lib/chef/resources.rb
index b580a01c29..37d1ca253f 100644
--- a/lib/chef/resources.rb
+++ b/lib/chef/resources.rb
@@ -41,6 +41,7 @@ require "chef/resource/gem_package"
 require "chef/resource/git"
 require "chef/resource/group"
 require "chef/resource/http_request"
+require "chef/resource/hostname"
 require "chef/resource/homebrew_package"
 require "chef/resource/ifconfig"
 require "chef/resource/ksh"
diff --git a/spec/unit/resource/hostname_spec.rb b/spec/unit/resource/hostname_spec.rb
new file mode 100644
index 0000000000..33f944dbc9
--- /dev/null
+++ b/spec/unit/resource/hostname_spec.rb
@@ -0,0 +1,43 @@
+#
+# Copyright:: Copyright 2018, 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 "spec_helper"
+
+describe Chef::Resource::Hostname do
+
+  let(:resource) { Chef::Resource::Hostname.new("foo") }
+
+  it "has a resource name of :hostname" do
+    expect(resource.resource_name).to eql(:hostname)
+  end
+
+  it "has a default action of set" do
+    expect(resource.action).to eql([:set])
+  end
+
+  it "runs at compile_time by default" do
+    expect(resource.compile_time).to eql(true)
+  end
+
+  it "reboots windows nodes by default" do
+    expect(resource.windows_reboot).to eql(true)
+  end
+
+  it "the hostname property is the name property" do
+    expect(resource.hostname).to eql("foo")
+  end
+end