Chef use cookbook_file in ruby block - ruby

I have the following code to figure out where Java is located on the box. Java comes with our application and what Java version that is included with the application differs.
def app_java_home
if Dir.exist?("#{app_home}/jre-server/linux")
Dir.chdir("#{app_home}/jre-server/linux") do
Dir.glob('jdk*').select { |f| File.directory? f }[0]
end
end
end
Then, in my cookbook I have
aws_s3_file "#{app_download_path}/#{app_s3['archive_file']}" do
bucket app_s3['bucket']
remote_path app_s3['remote_path']
region aws_region
not_if { ::Dir.exists?(app_bin_dir) }
not_if { ::File.exists?("#{app_download_path}/#{app_s3['archive_file']}") }
end
execute 'extract' do
user 'root'
command "unzip #{app_download_path}/#{app_s3['archive_file']} > /dev/null"
not_if { ::Dir.exists?("#{app_home}/ourapp") }
only_if { ::File.exists?("#{app_download_path}/#{app_s3['archive_file']}") }
end
execute 'move' do
user 'root'
command "mv #{app_download_path}/ourapp/ #{app_install_path}"
not_if { ::Dir.exists?(app_home) }
end
cookbook_file "#{app_java_home}/jre/lib/security/local_policy.jar" do
source %W[#{app_release}/local_policy.jar default/local_policy.jar]
owner app_user_name
group app_group_name
mode 0755
end
cookbook_file "#{app_java_home}/jre/lib/security/US_export_policy.jar" do
source %W[#{app_release}/US_export_policy.jar default/US_export_policy.jar]
owner app_user_name
group app_group_name
mode 0755
end
However, the two cookbook_file resources fails because it can't find the directory:
No such file or directory # dir_chdir - /ourapp/jre-server/linux/
After a lot of googling, I've come to the conclusion that it's a .. "missmatch" (?) between compile time and run time of the recipes. Basically, if I understand it correctly, it tries to run the cookbook_file resource(s) first but fails. So never downloads, unpacks and installs the app artefact.
I've tried running app_java_home when the directory exists, and it does seem to work the way I want it..
I tried putting the cookbook_file resources in a ruby_block, but then I instead get:
undefined method `cookbook_file' for Chef::Resource::RubyBlock
The app_java_home .. function (?) used to look like this:
def app_java_home
"#{app_home}/jre-server/linux/#{jdk_version}"
end
Where jdk_version came from the databag. This worked fine, but we have a long standing bug/feature request in our system where it sometimes happens that "they" get the version they put in the databag wrong, causing all sorts of problems.. So they want a way to remove this dependency and instead "figure this out" dynamically.
Ruby and Chef isn't my forte, so I'm not sure what to try next. I have found references to Chef::Resources::CookbookFile (which, if I understand it, could/should be used inside ruby_blocks), but can't find any examples or documentation about it. The link on RubyDocs is broken.

Adding an answer here for a better explanation.
Any (Ruby) code that is not within any of the Chef resources, will run in Compile phase
All resource declarations will run in Convergence phase in the order they are defined
Thankfully, there is a way to make resources run in Compile phase if so required. Though IMHO it should be done sparingly and in exceptional cases.
As per your comment aws_s3_file and execute resources are the ones that unpack the app (and create the directory). In this case, it seems you want them to run in compile phase.
Prior to Chef client 16.0
Use the run_action option with the action that should be performed at the compile time. For example execute resource takes action :run:
# Note action ":nothing" and "run_action"
execute 'extract' do
user 'root'
command "unzip #{app_download_path}/#{app_s3['archive_file']} > /dev/null"
not_if { ::Dir.exists?("#{app_home}/ourapp") }
only_if { ::File.exists?("#{app_download_path}/#{app_s3['archive_file']}") }
action :nothing
end.run_action(:run)
Chef client 16.0 onwards
We can add a common property to the resources. Example with execute resource:
# Note the extra property "compile_time"
execute 'extract' do
user 'root'
command "unzip #{app_download_path}/#{app_s3['archive_file']} > /dev/null"
not_if { ::Dir.exists?("#{app_home}/ourapp") }
only_if { ::File.exists?("#{app_download_path}/#{app_s3['archive_file']}") }
compile_time true
end
And finally to answer the subject of the question:
Chef use cookbook_file in ruby block
This is not possible. Refer to the first point on the top. If we want Ruby code to run during converge (instead of compile), we put it within the ruby_block resource. So it can contain code like (for example):
ruby_block 'get directory' do
block do
def app_java_home
"#{app_home}/jre-server/linux/#{jdk_version}"
end
end
end

With the help of #seshadri_c, I finally managed to solve the problem! It took some doing, because I kept misunderstanding the suggestions etc.
So this is what I came up with (for posterity):
def jdk_version(required = true)
base_dir = "#{app_home}/jre-server/linux"
if Dir.exist?("#{base_dir}")
Dir.chdir("#{app_home}/jre-server/linux") do
Dir.glob("jdk*").each do |f|
if File.directory?(f)
return "#{f}"
end
end
end
end
end
def app_java_home
return "#{app_home}/jre-server/linux/#{jdk_version}"
end
Turns out I need to get just the version, individually, as well, so I rearranged the functions a bit. I'm sure it could be written much cleaner, but here the trick was to use return instead of puts/print! Well, I'm a programmer, but not a Ruby programmer so didn't know that was an option..
Then, in the cookbook, I added the .run_action() where needed. I didn't need them for the cookbook_file, which simplified things a bit:
aws_s3_file "#{app_download_path}/#{app_s3['archive_file']}" do
bucket app_s3['bucket']
remote_path app_s3['remote_path']
region aws_region
not_if { ::Dir.exists?(app_bin_dir) }
not_if { ::File.exists?("#{app_download_path}/#{app_s3['archive_file']}") }
end.run_action(:create)
execute 'extract' do
user 'root'
command "unzip #{app_download_path}/#{app_s3['archive_file']} > /dev/null"
not_if { ::Dir.exists?("#{app_home}/app") }
only_if { ::File.exists?("#{app_download_path}/#{app_s3['archive_file']}") }
end.run_action(:run)
execute 'move' do
user 'root'
command "mv #{app_download_path}/app/ #{app_install_path}"
not_if { ::Dir.exists?(app_home) }
end.run_action(:run)
# JCE Unlimited Strength Jurisdiction Policy Files
cookbook_file "#{app_java_home}/jre/lib/security/local_policy.jar" do
source %W[#{app_release}/local_policy.jar default/local_policy.jar]
owner app_user_name
group app_group_name
mode 0755
end
cookbook_file "#{app_java_home}/jre/lib/security/US_export_policy.jar" do
source %W[#{app_release}/US_export_policy.jar default/US_export_policy.jar]
owner app_user_name
group app_group_name
mode 0755
end
With all that, everything is running exactly when they're supposed to and everything seems to be working.

Related

Execute instructions in chef recipes only for Test Kitchen converge action

I need a way to run parts of chef recipes only in case of converge action in Test Kitchen.
I found a way to do it for ChefSpec:
unless defined?(ChefSpec)
cookbook_file "/home/#{node['user']}/script.sh" do
source 'install.sh'
owner node['user']
mode '0755'
action :create
end
end
How I can do it for Kitchen tool?
This requirement has been discussed in detail on a feature request on Github.
There are two ways to do this. One is to define an environment variable such as TEST_KITCHEN, then use it in recipe with if condition, only_if or not_if guards.
Below should work:
Set the environment variable:
export TEST_KITCHEN="1"
Run the resource conditionally:
if ENV['TEST_KITCHEN']
cookbook_file "/home/#{node['user']}/script.sh" do
source 'install.sh'
owner node['user']
mode '0755'
action :create
end
end
Other way is to use a node attribute, something like node['test_kitchen'] set to true and use it to run actions conditionally.
cookbook_file "/home/#{node['user']}/script.sh" do
source 'install.sh'
owner node['user']
mode '0755'
action :create
only_if { node['test_kitchen'] }
end

How to do an "unless" conditional when changing permissions in a ruby_block in chef?

In chef I Have a ruby_block where I am changing permissions and ownership of a directory. How can I do a check where the permissions are only changed if they have not already been changed by the " FileUtils.chown" statement? I need to do this within the ruby_block if possible because i am ganna have other code in the ruby block. What would my "unless" statement be? Here is my code:
ruby_block 'exe' do
block do
FileUtils.chmod 0755, '/make/news'
FileUtils.chown('root', 'root', '/make/news')
end
end
The correct way to do this is to use Chef's file resource:
file '/make/news' do
mode 0755
owner 'root'
group 'root'
end
You're going down the road of trying to re-write the file resource which is not a good idea.
Using the Chef Resource's not_if Guard
Chef resources share a number of common functions. The ruby_block resource supports the not_if property as a conditional guard. The general format is:
ruby_block 'custom chmod' do
block do
#
end
not_if { true }
end
So, you could program your logic this way, but it will eventually bite you badly. Chef often works better if you use a file or directory resource declaratively using a separate block to manage permissions, and then (if necessary) chain it with a notification from some other block that needs a given permission set. For example:
directory '/make/news' do
mode '0755'
owner 'root'
group 'root'
action :nothing
end
ruby_block 'do something with news' do
block do
#
end
only_if { true }
notifies :create, 'directory[/make/news]', :before
end
That said, the goal of configuration management is to continuously converge, so I'd strongly question whether creating this interdependency between resource blocks is truly necessary in the first place. If possible, just converge your directory permissions every time to enforce them. While this may create a sequencing dependency within your recipe, a more declarative approach often simplifies cookbook and recipe debugging in the long run. Your individual mileage may vary.

Keeping files updated with a Chef recipe

The challenge prompt is above, and my latest attempt is below. The directories and files are created as expected, and the read-out after executing chef-apply multipleCopies.rb tells me the files are linked, but when I update any one of the files, the others do not follow suit. Any ideas? Here is my code:
for x in 1..3
directory "multipleCopy#{x}" do
mode '0755'
action :create
end
end
file "multipleCopy1/secret.txt" do
mode '0755'
action :create
end
for x in 2..3
link "multipleCopy#{x}/secret.txt" do
to "multipleCopy1/secret.txt"
link_type :hard
subscribes :reload, "multipleCopy1/secret.txt", :immediately
end
end
Note: For less headache, I am testing the recipe locally before uploading to the ubuntu server referenced in the prompt, which is why my file paths are different and why I have not yet included the ownership properties.
So a file hard link doesn't seem to be what the question is going for (though I would say your solution is maybe better since this is really not what Chef is for, more on that later). Instead they seem to want you to have three actually different files, but sync the contents.
So first the easy parts, creating the directories and the empty initial files. It's rare to see those for loops used in Ruby code, though it is syntactically valid:
3.times do |n|
directory "/var/save/multipleCopy#{n+1}" do
owner "ubuntu"
group "root"
mode "755"
end
file "/var/save/multipleCopy#{n+1}/secret.txt" do
owner "root
group "root"
mode "755"
end
end
But that doesn't implement the hard part of sync'ing the files. For that we need to first analyze the mtimes on the files and use the most recent as the file content to set.
latest_file = 3.times.sort_by { |n| ::File.mtime("/var/save/multipleCopy#{n+1}/secret.txt") rescue 0 }
latest_content = ::File.read("/var/save/multipleCopy#{latest_file+1}/secret.txt") rescue nil
and then in the file resource:
file "/var/save/multipleCopy#{n+1}/secret.txt" do
owner "root
group "root"
mode "755"
content latest_content
end
As for this not being a good use of Chef: Chef is about writing code which asserts the desired state of the machine. In the case of files like this, rather than doing this kind of funky stuff to check if a file has been edited, you would just say that Chef owns the file content for all three and if you want to update it, you do it via your cookbook (and then usually use a template or cookbook_file resource).

How to write ChefSpec Unit Test for ruby_block resource?

How to write the ChefSpec Unit tests for ruby_block? What if the local variables are declared in the recipe? How will it be handled?
Here is the code of a recipe:
package 'autofs' do
action :install
end
src = '/etc/ssh/sshd_config'
unless ::File.readlines(src).grep(/^PasswordAuthentication yes/).any?
Chef::Log.warn "Need to add/change PasswordAuthentication to yes in sshd config."
ruby_block 'change_sshd_config' do
block do
srcfile = Chef::Util::FileEdit.new(src)
srcfile.search_file_replace(/^PasswordAuthentication no/, "PasswordAuthentication yes")
srcfile.insert_line_if_no_match(/^PasswordAuthentication/, "PasswordAuthentication yes")
srcfile.write_file
end
end
end
unless ::File.readlines(src).grep('/^Banner /etc/issue.ssh/').any?
Chef::Log.warn "Need to change Banner setting in sshd config."
ruby_block 'change_sshd_banner_config' do
block do
srcfile = Chef::Util::FileEdit.new(src)
srcfile.search_file_replace(/^#Banner none/, "Banner /etc/issue.ssh")
srcfile.insert_line_if_no_match(/^Banner/, "Banner /etc/issue.ssh")
srcfile.write_file
end
end
end
As I am new to ChefSpec, I am able to write the code for the basic resources. I have written the Unit Test as below:
require 'chefspec'
describe 'package::install' do
let(:chef_run) { ChefSpec::SoloRunner.new(platform: 'ubuntu', version: '16.04').converge(described_recipe) }
it 'install a package autofs' do
expect(chef_run).to install_package('autofs')
end
it 'creates a ruby_block with an change_sshd_config' do
expect(chef_run).to run_ruby_block('change_sshd_config')
end
it 'creates a ruby_block with an change_sshd_banner_config' do
expect(chef_run).to run_ruby_block('change_sshd_banner_config')
end
end
Does the above implementation is corrct? I am not able to figure out how it can be written for complex resources like ruby block, etc. And how the local variables declared in recipe should be taken care.
Thanks in advance..
let(:conf) { double('conf') }
before do
allow(File).to receive(:readlines).with('/etc/ssh/sshd_config').and_return(["something"])
allow(File).to receive(:readlines).with('/etc/ssh/sshd_config').and_return(["something"])
end
it 'creates a ruby_block with an change_sshd_config' do
expect(chef_run).to run_ruby_block('change_sshd_config')
expect(Chef::Util::FileEdit).to receive(:new).with('/etc/ssh/sshd_config').and_return(conf)
confile = Chef::Util::FileEdit.new('/etc/ssh/sshd_config')
end
Do the same thing for other ruby block as well! Mostly it will work.
Or
You can test using inspec to test the state of your system. It seems like you may want to test the state of your system for the way sshd is configured after Chef has applied config. You could accomplish that with inspec with something like the following snippet:
describe file('/etc/ssh/sshd_config') do
its('content') { should match /whatever/ }
end
I hope this helps!
Unit tests should be testing that specific inputs produce the expected outputs. By expecting Chef to have run_ruby_block, you're essentially saying "Does Chef work the way I expect it to" -- not, "Does my ruby_block resource work the way I expect it to".
You should use ChefSpec to validate that the side effects of the ruby_block are what you expect them to be. That is, that the file(s) are modified. The ChefSpec documentation on RenderFileMatchers is probably what you're looking for.

Passing variables between chef resources

i would like to show you my use case and then discuss possible solutions:
Problem A:
i have 2 recipes, "a" and "b".. "a" installs some program on my file system (say at "/usr/local/bin/stuff.sh" and recipe "b" needs to run this and do something with the output.
so recipe "a" looks something like:
execute "echo 'echo stuff' > /usr/local/bin/stuff.sh"
(the script just echo(es) "stuff" to stdout)
and recipe "b" looks something like:
include_recipe "a"
var=`/usr/local/bin/stuff.sh`
(note the backquotes, var should contain stuff)
and now i need to do something with it, for instance create a user with this username. so at script "b" i add
user "#{node[:var]}"
As it happens, this doesn't work.. apparently chef runs everything that is not a resource and only then runs the resources so as soon as i run the script chef complains that it cannot compile because it first tries to run the "var=..." line at recipe "b" and fails because the "execute ..." at recipe a did not run yet and so the "stuff.sh" script does not exist yet.
Needless to say, this is extremely annoying as it breaks the "Chef runs everything in order from top to bottom" that i was promised when i started using it.
However, i am not very picky so i started looking for alternative solutions to this problem, so:
Problem B: i've run across the idea of "ruby_block". apparently, this is a resource so it will be evaluated along with the other resources. I said ok, then i'd like to create the script, get the output in a "ruby_block" and then pass it to "user". so recipe "b" now looks something like:
include_recipe "a"
ruby_block "a_block" do
block do
node.default[:var] = `/usr/local/bin/stuff.sh`
end
end
user "#{node[:var]}"
However, as it turns out the variable (var) was not passed from "ruby_block" to "user" and it remains empty. No matter what juggling i've tried to do with it i failed (or maybe i just didn't find the correct juggling method)
To the chef/ruby masters around: How do i solve Problem A? How do i solve Problem B?
You have already solved problem A with the Ruby block.
Now you have to solve problem B with a similar approach:
ruby_block "create user" do
block do
user = Chef::Resource::User.new(node[:var], run_context)
user.shell '/bin/bash' # Set parameters using this syntax
user.run_action :create
user.run_action :manage # Run multiple actions (if needed) by declaring them sequentially
end
end
You could also solve problem A by creating the file during the compile phase:
execute "echo 'echo stuff' > /usr/local/bin/stuff.sh" do
action :nothing
end.run_action(:run)
If following this course of action, make sure that:
/usr/local/bin exist during Chef's compile phase;
Either:
stuff.sh is executable; OR
Execute it through a shell (e.g.: var=`sh /usr/local/bin/stuff.sh`
The modern way to do this is to use a custom resource:
in cookbooks/create_script/resources/create_script.rb
provides :create_script
unified_mode true
property :script_name, :name_property: true
action :run do
execute "creating #{script_name}" do
command "echo 'echo stuff' > #{script_name}"
not_if { File.exist?(script_name) }
end
end
Then in recipe code:
create_script "/usr/local/bin/stuff.sh"
For the second case as written I'd avoid the use of a node variable entirely:
script_location = "/usr/local/bin/stuff.sh"
create_script script_location
# note: the user resources takes a username not a file path so the example is a bit
# strange, but that is the way the question was asked.
user script_location
If you need to move it into an attribute and call it from different recipes then there's no need for ruby_blocks or lazy:
some cookbook's attributes/default.rb file (or a policyfile, etc):
default['script_location'] = "/usr/local/bin/stuff.sh"
in recipe code or other custom resources:
create_script node['script_location']
user node['script_location']
There's no need to lazy things or use ruby_block using this approach.
There are actually a few ways to solve the issue that you're having.
The first way is to avoid the scope issues you're having in the passed blocks and do something like ths.
include_recipe "a"
this = self
ruby_block "a_block" do
block do
this.user `/usr/local/bin/stuff.sh`
end
end
Assuming that you plan on only using this once, that would work great. But if you're legitimately needing to store a variable on the node for other uses you can rely on the lazy call inside ruby to do a little work around of the issue.
include_recipe "a"
ruby_block "a_block" do
block do
node.default[:var] = `/usr/local/bin/stuff.sh`.strip
end
end
user do
username lazy { "#{node[:var]}" }
end
You'll quickly notice with Chef that it has an override for all default assumptions for cases just like this.

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