work around 'Exception::ImmutableAttributeModification'

[anatolijd]

Running this recipe under chef-11.8.0 I get this:

Chef::Exceptions::ImmutableAttributeModification
------------------------------------------------
Node attributes are read-only when you do not specify which precedence level to set. To set an attribute use code like `node.default["key"] = "value"'


Cookbook Trace:
---------------
  /var/chef/cache/cookbooks/jmxtrans/recipes/default.rb:23:in `block in from_file'
  /var/chef/cache/cookbooks/jmxtrans/recipes/default.rb:22:in `each'
  /var/chef/cache/cookbooks/jmxtrans/recipes/default.rb:22:in `from_file'

Relevant File Content:
----------------------
/var/chef/cache/cookbooks/jmxtrans/recipes/default.rb:

 16:  end
 17:  
 18:  user node['jmxtrans']['user']
 19:  
 20:  # merge stock jvm queries w/ container specific ones into single array
 21:  servers = node['jmxtrans']['servers']
 22:  servers.each do |server|
 23>>   server['queries'] = node['jmxtrans']['default_queries']['jvm']
 24:    case server['type']
 25:    when 'tomcat'
 26:      server['queries'] << node['jmxtrans']['default_queries']['tomcat']
 27:    end
 28:    server['queries'].flatten!
 29:  end
 30:  
 31:  ark "jmxtrans" do
 32:    url node['jmxtrans']['url']

Since it is the only place where we refer to node['jmxtrans']['servers'] attribute in recipe - .dup can be used to work it around (I hope).

[anatolijd]

forgot to mention -a fix from PR #13 did not work for me, I get another exception:

================================================================================
Recipe Compile Error in /var/chef/cache/cookbooks/jmxtrans_rf/recipes/default.rb
================================================================================


Chef::Exceptions::ImmutableAttributeModification
------------------------------------------------
Node attributes are read-only when you do not specify which precedence level to set. To set an attribute use code like `node.default["key"] = "value"'


Cookbook Trace:
---------------
  /var/chef/cache/cookbooks/jmxtrans/recipes/default.rb:28:in `block in from_file'
  /var/chef/cache/cookbooks/jmxtrans/recipes/default.rb:22:in `each'
  /var/chef/cache/cookbooks/jmxtrans/recipes/default.rb:22:in `from_file'
  /var/chef/cache/cookbooks/jmxtrans_rf/recipes/default.rb:11:in `from_file'


Relevant File Content:
----------------------
/var/chef/cache/cookbooks/jmxtrans/recipes/default.rb:

 21:  servers = node.default['jmxtrans']['servers']
 22:  servers.each do |server|
 23:    server['queries'] = node['jmxtrans']['default_queries']['jvm']
 24:    case server['type']
 25:    when 'tomcat'
 26:      server['queries'] << node['jmxtrans']['default_queries']['tomcat']
 27:    end
 28>>   server['queries'].flatten!
 29:  end
 30:  
 31:  ark "jmxtrans" do
 32:    url node['jmxtrans']['url']
 33:    checksum node['jmxtrans']['checksum']
 34:    version "latest"
 35:    prefix_root '/opt'
 36:    prefix_home '/opt'
 37:    owner node['jmxtrans']['user']

I know about collectd jmx plugin, the problem is that it produces 'unfriendly' graphite names for JMX metrics, and even with chain mangling I can't separate GenericJMX-- with '.' (I can, but it gets replaced back by write_graphite plugin ).