I need a help to set a global variable in chef recipes.
I have below series of recipes:
Discovers the tomcat from path variable/attibutes/default.rb:
default['tomcat_cookbook']['tomcathome']="['/home/tomcat','/home/ApacheTomcat']"
This recipe will identify the tomcat installation as either one of the directory will be available on server out of this two directories.
Lets say, if it sets the tomcathome to directory "/home/tomcat", I have some more subsequent recipes like start/stop/restart tomcat.
Currently for every recipe I am running discovery logic inside stop/start recipes while knowing that on a particular server, tomcathome is set to "/home/tomcat" .
Is there any way I can remove duplicate code for tomcat home discovery and make use of the identified tomcathome variable for remaining recipes.
Please suggest.
I think this would be a good use of libraries. I'll assume the cookbook name is tomcat_cookbook. In the libraries folder in a cookbook, create a file called path.rb.
Add the following code into the path.rb file. I prefer to namespace my libraries to organize my methods using CookbookName::ModuleName format.
libraries/path.rb:
module TomcatCookbook
module Path
def install_path
node['tomcat_cookbook']['tomcathome'].each do |path|
return path if ::Dir.exist?(path)
end
end
end
end
Within any recipe, you can include this module and use the methods in it:
# Use this include for use in the recipe
Chef::Recipe.send(:include, TomcatCookbook::Path)
# Use this include for using methods in the directory resource itself
Chef::Resource::Directory.send(:include, TomcatCookbook::Path)
Chef::Log.info("Install Path: #{install_path}")
directory "tomcat_install_path" do
path install_path
action :create
end
In certain situations, I have needed to create a common cookbook which includes only libraries which I can use across multiple cookbooks.
Related
I have a Chef cookbook with many recipes that have the same code, beside other particular things.
template 'stack_file' do
local true
source File.join(base_dir, 'stack_templates/admin.yml.erb')
path File.join(base_dir, 'stacks/admin.yml')
variables(context)
end
template 'settings_file' do
sensitive true
local true
source File.join(base_dir, 'config_templates/settings_admin.yml.erb')
path File.join(base_dir, 'configs/settings_admin.yml')
variables(context)
end
Is it possible to somehow put this code in a method that I would call with my source_file, destination_file and variables?
I guess you can write a module and include it in your recipes as you do in plain Ruby.
module StackFile
...the code you want to share...
end
Then you can use:
inlclude StackFile
or
Chef::Recipe.send(:include, StackFile)
or when using *_if conditions
Chef::Resource.send(:include, StackFile)
Do this:
create new cookbook.
don't create recipes in it, but instead create a resource
you can define any parameters (inputs like source file, dest file etc like you mentioned)
add your templates to the new cookbook.
in your other cookbooks, create dependency to the previously created cookbook. This will enable you to call the resource you created there (remember that when you call resource from another cookbook and it is creating templates, it will try to take the template file from the current cookbook and not the one where the resource is defined. That is why you need to specify cookbook name when creating template (in the shared cookbook's resource) - see cookbook attribute of https://docs.chef.io/resource_template.html)
Repeat for any number of cookbooks.
I am newbie to puppet and I wonder how I can pass arguments to the command line. I will explain myself:
This is the command that I'm running (puppet apply):
C:>puppet apply --environment test -l C:\Puppet_logs\log.log C:\ProgramData\PuppetLabs\code\environments\test\manifests\site.pp
Site.pp:
File { backup => false }
node default {
include 'tn'
}
It means that I am running 'tn' which is one of the modules in my puppet project.
For example,
I have these modules in my puppet project:
tn
ps
av
So to run each module I need to go to this site.pp file and change it to
include 'ps'
or
include 'av'
My question is -
How do I pass these modules as arguments to the puppet apply command?
I know that I can create 3 .pp files that each one contains one module (ps, av, tn)
And then my command will look like:
puppet apply --environment test -l C:\Puppet_logs\log.log C:\ProgramData\PuppetLabs\code\environments\test\manifests\ps.pp
puppet apply --environment test -l C:\Puppet_logs\log.log C:\ProgramData\PuppetLabs\code\environments\test\manifests\av.pp
puppet apply --environment test -l C:\Puppet_logs\log.log C:\ProgramData\PuppetLabs\code\environments\test\manifests\tn.pp
But, I think it's not a good solution..
Is there another way to pass these modules as arguments to the puppet apply?
If I didn't mention - each module is responsible for different actions.
thanks !!!
I know that I can create 3 .pp files that each one contains one module
(ps, av, tn)
[...]
But, I think it's not a good solution.
Why isn't it a good solution? It seems perfectly sensible to me that if you have three different things you want to be able to do, then you have a separate file to use to accomplish each.
Nevertheless, if your modules do not use each other, then you could probably accomplish what you describe by relying on tags. Have your site manifest include all three modules:
File { backup => false }
node default {
include 'tn'
include 'ps'
include 'av'
}
Then use the --tags option to select only one of those modules and all the other classes it brings in:
puppet apply --tags ps --environment test -l C:\Puppet_logs\log.log C:\ProgramData\PuppetLabs\code\environments\test\manifests\site.pp
A pp file is a class file not a module, a module contains the classes and anything else needed to support/test those classes, take a look at https://puppet.com/docs/puppet/5.5/modules_fundamentals.html.
Look at how modules are laid out on https://forge.puppet.com/
It’s well worth looking at the PDK https://puppet.com/docs/pdk/1.x/pdk.html as it'll build a module for you, you just need to add the classes.
In your case you probably want to create a new module (let’s call it mymodule) and in that module put all your tn.pp ps.pp and av.pp class files under the C:\ProgramData\PuppetLabs\code\environments\test\modules\mymodule\manifests directory.
Then for local testing use the examples pattern, so in your module you’ll have an examples directory and in there you might have a file called ps.pp which would contain include mymodule::ps to include that ps.pp class file.
The aim of the examples directory is to give you a method of passing in parameters for local testing.
Back in your site.pp file you’d apply is with:
Node default {
Include mymodule::ps
}
So now you want to apply different classes to the nodes and there you hit the world of node classification and there are many ways you can do that. In your case I think you’re probably doing this on a small scale so you’d have;
Node psserver.example.com {
Include mymodule::ps
}
Node tnserver.example.com {
Include mymodule::tn
}
Have a look at some of the online training https://puppet.com/learning-training/kits/puppet-language-basics
I want to create a directory from chef recipe to backup my existing artifacts. i want to create the backup directory with following format.
appname_bkp_17-10-11-125845
for example I need to create this directory and add the directory name into a variable which is something like;
bkp_dir_name = appname_bkp_17-10-11-125845
Please advice.
While Chef is a DSL, it is still first and foremost pure Ruby. You should try to learn a little about Ruby basics before committing to Chef entirely, because a lot of what you might want to do will be more efficient if you know the language.
time = Time.now.strftime("%F-%T").gsub(':','')
dir = "appname_bkp_#{time}"
path = ::File.join(node['default']['default_backup_path'], dir)
# Chef resource to create a directory with default properties
directory path
I am trying to use the main gem for making command line utilities. This was presented in a recent Ruby Rogues podcast.
If I put all the code in one file and require that file, then rspec gives me an error, as the main dsl regards rpsec as a command line invocation of the main utility.
I can break out a method into a new file and have rspec require that file. Suppose you have this program, but want to put the do_something method in a separate file to test with rspec:
require 'main'
def do_something(foo)
puts "foo is #{foo}"
end
Main {
argument('foo'){
required # this is the default
cast :int # value cast to Fixnum
validate{|foo| foo == 42} # raises error in failure case
description 'the foo param' # shown in --help
}
do_something(arguments['foo'].value)
}
What is the convenient way to distribute/deploy a ruby command line program with multiple files? Maybe create a gem?
You are on the right track for testing - basically you want your "logic" in separate files so you can unit test them. You can then use something like Aruba to do an integration test.
With multiple files, your best bet is to distribute it as a RubyGem. There's lots of resources out there, but the gist of it is:
Put your executable in bin
Put your files in lib/YOUR_APP/whatever.rb where "YOUR_APP" is the name of your app. I'd also recommend namespacing your classes with modules named for your app
In your executable, require the files in lib as if lib were in the load path
In your gemspec, make sure to indicate what your bin files are and what your lib files are (if you generate it with bundle gem and are using git, you should be good to go)
This way, your app will have access to the files in lib at runtime, when installed with RubyGems. In development, you will need to either do bundle exec bin/my_app or RUBYLIB=lib bin/my_app. Point is, RubyGems takes care of the load path at runtime, but not at development time.
I have following Chef cookbook:
deploy "/home/prj" do
repo "https://path_to_repo"
user node.project_owner
group node.project_owner
symlink_before_migrate({})
end
How can I access to the provider's release path? In my case in will be: /home/prj/releases/20120506125222/ .
It depends on where you want to access the release path. "Inside" the resource, i.e. the callbacks, that's easily possible using something iike
deploy "/home/prj" do
before_migrate do
gemfile = File.read("#{release_path}/Gemfile")
end
end
Outside of the resource, you don't have the release_path variable available. You can however use the current symlink which points to the currently deployed version, i.e. the last release:
current_path = "home/prj/current"
release_path = File.readlink(current_path)
Most of the time, you can to things directly in the current_path without having to resort to resolving the symlink target.
That said, you typically don't want to actually do things in there directly. Instead, you are encouraged to generate additional files in the shared directory (i.e. /home/prk/shared) and let chef symlink those files into the release during deployment. That's exactly what symlink_before_migrate is for. That way, you don't need to actually know the release path yourself but can let chef handle that for you.