{"id":31839,"date":"2022-11-22T05:53:06","date_gmt":"2022-11-22T05:53:06","guid":{"rendered":"https:\/\/www.devopsschool.com\/blog\/?p=31839"},"modified":"2022-12-23T05:45:28","modified_gmt":"2022-12-23T05:45:28","slug":"chef-tutorials-working-with-chef-attributes","status":"publish","type":"post","link":"https:\/\/www.devopsschool.com\/blog\/chef-tutorials-working-with-chef-attributes\/","title":{"rendered":"Chef Tutorials: Working with Chef Attributes"},"content":{"rendered":"\n

Attributes represent information about your node. In addition to the information that can be automatically generated by ohai<\/code>, you can set attributes in Chef recipes or in separate attribute files.<\/p>\n\n\n\n

Because attributes can be defined in multiple places, all attribute values are composed together during a Chef run according to the priority levels<\/p>\n\n\n\n

Attributes defined by\u00a0ohai<\/code>\u00a0have the highest priority, followed by attributes defined in a recipe, then attributes defined in an attribute file. In other words, recipe attributes have a higher priority than those defined in attribute file in cookbooks, and will override them by default. Attributes defined by\u00a0ohai<\/code>\u00a0trump everything else.<\/p>\n\n\n\n

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Declaring Attributes in Chef Recipe<\/h2>\n\n\n\n
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Attributes can be set directly in recipes. Image shows the format of an attribute when it is set in a recipe. You must precede the attribute name with node. when you set an attribute directly in a recipe.<\/p>\n\n\n\n

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\"\"<\/figure>\n\n\n
node.default<\/span>['devopsschool'<\/span>]['message'<\/span>] = 'Hello People'<\/span>\n\n\nlog \"Welcome to Chef, #{node['devopsschool']['message']}!\"<\/span> do<\/span>\n  level :info\nend\n\nlog \"Welcome to DevOps\"<\/span> do<\/span>\n  level :info\nend<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
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node.default<\/span>['web'<\/span>]['file'<\/span>] = '\/opt\/index.html'<\/span>\n\n\n\nfile \"#{node['web']['file']}\"<\/span> do<\/span>\n  content \"Welcome to Chef Class\"<\/span>\nend<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
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\"\"<\/figure>\n\n\n\n
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Declaring Attributes in Chef Cookbooks<\/h2>\n\n\n\n
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Attribute files are located in the attributes<\/em> folder of a cookbook. Similar to recipes, the default attribute file is called:<\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
\"\"<\/figure>\n\n\n\n
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In cookbook, I visualize three levels of attributes: <\/strong><\/p>\n\n\n\n
– Default values to converge successfully — attributes\/default.rb <\/p>\n\n\n\n
– Local testing override values — JSON or .kitchen.yml (have you tried chef_zero using ChefDK and Kitchen?) <\/p>\n\n\n\n
– Environment\/role override values <\/p>\n\n\n\n
SUMMARY of Attributes in Recipe and Cookbook<\/h2>\n\n\n\n
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<\/p>\n\n\n
In an attributes file you don't have to type '<\/span>node' so that this in attributes\/default.rb:\n\ndefault['<\/span>foo']['<\/span>bar']['<\/span>baz'] = '<\/span>qux'\n\nIn an recipes\/whatever.rb file\n\nnode.default['<\/span>foo']['<\/span>bar']['<\/span>baz'] = '<\/span>qux'<\/span><\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>","protected":false},"excerpt":{"rendered":"
Attributes represent information about your node. In addition to the information that can be automatically generated by ohai, you can set attributes in Chef recipes or in separate attribute files. Because attributes can be defined in multiple places, all attribute values are composed together during a Chef run according to the priority levels Attributes defined by\u00a0ohai\u00a0have…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_kad_post_transparent":"","_kad_post_title":"","_kad_post_layout":"","_kad_post_sidebar_id":"","_kad_post_content_style":"","_kad_post_vertical_padding":"","_kad_post_feature":"","_kad_post_feature_position":"","_kad_post_header":false,"_kad_post_footer":false,"_kad_post_classname":"","_joinchat":[],"footnotes":""},"categories":[2],"tags":[],"class_list":["post-31839","post","type-post","status-publish","format-standard","hentry","category-uncategorised"],"_links":{"self":[{"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/posts\/31839","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/comments?post=31839"}],"version-history":[{"count":5,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/posts\/31839\/revisions"}],"predecessor-version":[{"id":31851,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/posts\/31839\/revisions\/31851"}],"wp:attachment":[{"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/media?parent=31839"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/categories?post=31839"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/tags?post=31839"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}