I try to read out the current recipe name while chef-client run and to store it in a variable or node attribute wihtin an recipe. Until yet i just found a way storing it into a node attribute but it always fails. This is my code:
ruby_block "Fetch Recipe Name From Run List" do
block do
Chef::Resource::RubyBlock.send(:include, Chef::Mixin::ShellOut)
s = shell_out("echo \"#{node['expanded_run_list']}\" | awk -F '::' '{print substr($3, 1, length($3)-1)}'" )
node.default['sftp-selfmade']['extracted_recipe'] = s.stdout
end
end
extracted_recipe = node['sftp-selfmade']['extracted_recipe']
# To debug the output of the node attribute.
execute 'TEST' do
command "echo \"TEST #{extracted_recipe}\""
end
Output:
* execute[TEST] action run
[execute] TEST
- execute echo "TEST "
Output should be:
- execute echo "TEST <Name-Of-Extracted-Recipe>"
I tried lot's of things as also storing the s.stdout output in a variable but this throws an NoMethodError during compiling stage. Also tried to use stronger values like node.override - this works but only by setting node.normal first and the setting it to node.override but this is not a satisfying solution to do this everytime within cookbook code again for deploying to new hosts. Tried also a solution reloading OHAI. But this also did not work. On a completely new host it also doesn't work after a 2nd chef-client run in case of attributes have been set then after first run.
Is there somebody who can help me out?
Found out the following solution:
expandedrecipe = node['expanded_run_list'].select{ |e| e.include? 'sftp-selfmade' }.first.split('::').last
That does the trick.
Related
In a rake task I'm writing some puts statements show changes while others don't. For instance changing
puts model+" | "+id
into
puts model+" * "+id
doesn't change in the output of the script. However in some places changing
puts "Connecting to "+site
into
puts "Connecting to ----"+site
shows the changes that where made.
In the places where any changes to the line doesn't change the output, adding a new puts statement before or after don't show up when the task is run. Commenting out lines of code around the unchanging puts statements that do the actual work cause the script to not execute those lines, just as it should, but changing or adding puts statements there do not change the output of the script.
Removing all other tasks and emacs backup files from the lib/tasks folder doesn't help. I've been bitten before by having a backup copy of a task with the same namespace and task name running instead of the one I was working on.
This is being run with Ruby 2.4.3 on OpenBSD 6.3-stable on a fx-8350. I would post the whole script but the company I'm working for won't allow it.
How about
puts "#{model} +/*/whatever #{site}"
It shouldn't matter to what sounds like a filesystem update issue (reboot), but it's probably better form to put the variables in the string like that instead of + "" them.
I have fingreprint.txt at the location "#{node['abc.d']}/fingreprint.txt"
The contents of the file are as below:
time="2015-03-25T17:53:12C" level=info msg="SHA1 Fingerprint=7F:D0:19:C5:80:42:66"
Now I want to retrieve the value of fingerprint and assign it to chef attribute
I am using the following ruby block
ruby_block "retrieve_fingerprint" do
block do
path="#{node['abc.d']}/fingreprint.txt"
Chef::Resource::RubyBlock.send(:include, Chef::Mixin::ShellOut)
command = 'grep -Po '(?<=Fingerprint=)[^"]*' path '
command_out = shell_out(command)
node.default['fingerprint'] = command_out.stdout
end
action :create
end
It seems not to be working because of missing escape chars in command = 'grep -Po '(?<=Fingerprint=)[^"]*' path '.
Please let me know if there is some other way of assigning file content to node attribute
Two ways to answer this: first I would do the read (IO.read) and parsing (RegExp.new and friends) in Ruby rather than shelling out to grep.
if IO.read("#{node['abc.d']}/fingreprint.txt") =~ /Fingerprint=([^"]+)/
node.default['fingerprint'] = $1
end
Second, don't do this at all because it probably won't behave how you expect. You would have to take in to account both the two-pass loading process and the fact that default attributes are reset on every run. If you're trying to make an Ohai plugin, do that instead. If you're trying to use this data in later resources, you'll probably want to store it in a global variable and make copious use of the lazy {} helper.
I am trying to execute Ruby logic on the fly in a Chef recipe and believe that the best way to achieve this is with a block.
I am having difficulty transferring variables assigned inside the block to the main code of the chef recipe. This is what I tried:
ruby_block "Create list" do
block do
to_use ||= []
node['hosts'].each do |host|
system( "#{path}/command --all" \
" | awk '{print $2; print $3}'" \
" | grep #{host} > /dev/null" )
unless $? == 0
to_use << host
end
end
node['hosts'] = to_use.join(',')
end
action :create
end
execute "Enable on hosts" do
command "#{path}/command --enable -N #{node['hosts']}"
end
Rather than try to re-assign the chef attribute on the fly, I also tried to create new variables in the block but still can't find a way to access them in the execute statement.
I was originally using a class and calling methods however it was compiled before the recipe and I really need the logic to be executed at runtime, during the recipe.
Your problem is compile time versus converge time. Your block will be run at converge time but at this time the node['host'] in the execute resource has already been evaluated.
The best solution in this case would be to use lazy evaluation so the variable will be expanded when the resource is converged instead of when it is compiled:
execute "Enable on hosts" do
command lazy { "#{path}/command --enable -N #{node['hosts']}" }
end
Here's a little warning though, the lazy operator has to include the full command attribute text and not only the variable, it can work only as first keyword after the attribute name.
I am using Capistrano v2.9.0.
I run this command:
cap deploy:tryout -S testvar=thing
and my deploy.rb contains this:
namespace :deploy do
task :tryout do
if defined? testvar
puts "param: #{testvar}\n"
else
puts "no branch!\n"
end
end
end
The output is "no branch!". How do I pass values from the command line? I tried looking into the code, and I can see options.rb where it adds the passed parameter to options[:pre_vars], but that seems to be an instance variable, and I can't figure out how to access it from my deploy script.
Solution:
The options can be accessed via #parent.variables hash, so if the command line string is testvar=thing, then #parent.variables[:testvar] has the value string.
This seems really ugly and hacky, but it works.
Edit:
Turns out it is also available locally via variables[:testvar]
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.