CODEWITHSUNDEEP
chef-infra
EisenWang
EisenWang

Reputation: 383

how to pass parameters to template in chef?

I just started to study chef. These days, I'm testing the sample of templates on -- https://docs.chef.io/resources/template/

But I failed all the times ... Here's my code --

  1. I created a cookbook named sample, and created a recipe named default.rb
file '/srv/www/htdocs/index.html' do
  content 'Hello World!'
end

include_recipe '::e'
  1. Then I created another recipe e.rb --
default['authorization']['sudo']['groups'] = %w(sysadmin wheel admin)

default['authorization']['sudo']['users'] = %w(jerry greg)

template '/tmp/test.txt' do
  source 'test.txt.erb'
  mode '0440'
  owner 'root'
  group 'root'
  variables(
    sudoers_groups: node['authorization']['sudo']['groups'],
    sudoers_users: node['authorization']['sudo']['users']
  )
end
  1. In this cookbook's templates folder, I created a erb file -- test.txt.erb
Defaults        !lecture,tty_tickets,!fqdn
root          ALL=(ALL) ALL
<% @sudoers_users.each  do |user| -%>
<%= user %>   ALL=(ALL) <%= "NOPASSWD:" if @passwordless %>ALL
<% end -%>

%sysadmin     ALL=(ALL) <%= "NOPASSWD:" if @passwordless %>ALL

<% @sudoers_groups.each do |group| -%>

<%= group %> ALL=(ALL) <%= "NOPASSWD:" if @passwordless %>ALL
<% end -%>
  1. Then after kick off "chef-client" , error message shows --
[2022-05-06T18:01:07+08:00] FATAL: NameError: undefined local variable or method `default' for cookbook: sample, recipe: e :Chef::Recipe
  1. Since error shows can't find the variable named 'default' and in that sample -- it's using node['authorization']['sudo']['groups'] to pass parameters to sudoers_groups, I think the e.rb maybe should be this --
node['authorization']['sudo']['groups'] = %w(sysadmin wheel admin)
node['authorization']['sudo']['users'] = %w(jerry greg)

template '/tmp/test.txt' do
  source 'test.txt.erb'
  mode '0440'
  owner 'root'
  group 'root'
  variables(
    sudoers_groups: node['authorization']['sudo']['groups'],
    sudoers_users: node['authorization']['sudo']['users']
  )
end
  1. But it still fails --
[2022-05-06T17:39:38+08:00] FATAL: NoMethodError: undefined method `[]' for nil:NilClass

I really messed up by this official sample. Please kind help me, Thanks in advance for any ideas.

Regards Eisen

Upvotes: 1

Views: 602

Answers (1)

seshadri_c
seshadri_c

Reputation: 7340

There are many places where attributes can be defined. For the purpose of this answer, we'll limit it to the recipe, and the attributes file. There are different precedence rules for attributes.

Defining in cookbook's attributes file, such as sample/attributes/default.rb with the default precedence:

default['authorization']['sudo']['groups'] = %w(sysadmin wheel admin)
default['authorization']['sudo']['users'] = %w(jerry greg)

Then the recipe sample/recipes/e.rb and template test.txt.erb could be used as you described in your question.

But when we define the attributes in recipe, we need to use the syntax node.<precedence>, such as node.default:

Defined in sample/recipes/e.rb:

node.default['authorization']['sudo']['groups'] = %w(sysadmin wheel admin)
node.default['authorization']['sudo']['users'] = %w(jerry greg)

template '/tmp/test.txt' do
# and so on

Upvotes: 2

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