Category: chef

Chef – Nodes ”; Previous Next Knife preflight shows details about all the nodes which uses a certain cookbook before uploading it to Chef server. Getting Started In order to get started, we need to have knife-preflight gem installed. Step 1 − Define the path in the gem file. vipin@laptop:~/chef-repo $ subl Gemfile source ”https://rubygems.org” gem ”knife-preflight” Step 2 − Run bundler to install knife-preflight gem. vipin@laptop:~/chef-repo $ bundle install Fetching gem metadata from https://rubygems.org/ …TRUNCATED OUTPUT… Installing knife-preflight (0.1.6) Working Method Run knife-preflight on the given cookbook. We can run the preflight command to find out which nodes and roles have the given cookbook in their expanded run lists. vipin@laptop:~/chef-repo $ knife preflight ntp Searching for nodes containing ntp OR ntp::default in their expanded run_list… 2 Nodes found www-staging.example.com cms-staging.example.com Searching for roles containing ntp OR ntp::default in their expanded run_list… 3 Roles found your_cms_role your_www_role your_app_role Found 6 nodes and 3 roles using the specified search criteria There are multiple ways for a cookbook to get executed on the node. You can assign the cookbook directly to a node by adding it to the node”s run list. You can add a cookbook to the role and add the role to the node”s run list. You can add the role to the run list of another role and add that other role to the node”s run list. A cookbook can be a dependency of another used cookbook. No matter how a cookbook ends up in a node”s run list, the knife preflight command will catch it as Chef stores all expanded lists of roles and recipes in node attributes. The knife preflight command issues a search for exactly those node attributes. Print Page Previous Next Advertisements ”;

Chef – Foodcritic ”; Previous Next Writing good cookbooks without any issue is quite a difficult task. But there are ways which can help in identifying the pitfalls. Flagging in Chef Cookbook is possible. Foodcritic is one of the best way of archiving it, which tries to identify possible issues with the logic and style of cookbooks. Foodcritic Setup Step 1 − Add Foodcritic gem. vipin@laptop:~/chef-repo $ subl Gemfile source ”https://rubygems.org” gem ”foodcritic”, ”~>2.2.0” Step 2 − Install the gem. vipin@laptop:~/chef-repo $ bundle install Fetching gem metadata from https://rubygems.org/ …TRUNCATED OUTPUT… Installing foodcritic (2.2.0) Foodcritic Gem Step 1 − Run Foodcritic on the cookbook. vipin@laptop:~/chef-repo $ foodcritic ./cookbooks/<Cookbook Name> FC002: Avoid string interpolation where not required: ./cookbooks/ mysql/attributes/server.rb:220 …TRUNCATED OUTPUT… FC024: Consider adding platform equivalents: ./cookbooks/<Cookbook Name>/ recipes/server.rb:132 Step 2 − Generate a detailed report. vipin@laptop:~/chef-repo $ foodcritic -C ./cookbooks/mysql cookbooks/<cookbook Name>/attributes/server.rb FC002: Avoid string interpolation where not required […] 85| default[”<Cookbook Name>”][”conf_dir”] = “#{mysql[”basedir”]}” […] cookbooks/<Cookbook Name>/recipes/client.rb FC007: Ensure recipe dependencies are reflected in cookbook metadata 40| end 41|when “mac_os_x” 42| include_recipe ”homebrew” 43|end 44| Working Method Foodcritic defines a set of rules and checks recipe agents, each one of them. It comes with multiple rules concerning various areas: styles, connectedness, attributes, string, probability, search, services, files, metadata, and so on. Print Page Previous Next Advertisements ”;

Chef – Chef-Client as Daemon ”; Previous Next Running Chef-Client as daemon helps in knowing the state of all the nodes at any point of time. This help in running the Chef-Client at any point of time. Pre-requisites The node should be registered with Chef server and it should be running Chef-Client without any error. Chef-Client in Daemon Mode Start Chef-Client in daemon mode, running every 30 minutes. user@server:~$ sudo chef-client -i 1800 In the above code, – i enables to run the Chef-Client in daemon mode on the required node and 1800 seconds define that the Chef-Client daemon should run in every 30 minutes. Validating Daemon Run Validate that the Chef-Client is running as a daemon. user@server:~$ ps auxw | grep chef-client The above command will grep the running daemon process of Chef-Client. Other Ways Instead of running Chef-Client as a daemon, we can run the same as a cron job. user@server:~$ subl /etc/cron.d/chef_client PATH=/usr/local/bin:/usr/bin:/bin # m h dom mon dow user command */15 * * * * root chef-client -l warn | grep -v ”retrying [1234]/5 in” The above cron job will run after every 15 minutes. Print Page Previous Next Advertisements ”;

Chef – Roles ”; Previous Next Roles in Chef are a logical way of grouping nodes. Typical cases are to have roles for web servers, database servers, and so on. One can set custom run list for all the nodes and override attribute value within roles. Create a Role vipin@laptop:~/chef-repo $ subl roles/web_servers.rb name “web_servers” description “This role contains nodes, which act as web servers” run_list “recipe[ntp]” default_attributes ”ntp” => { ”ntpdate” => { ”disable” => true } } Once we have the role created, we need to upload to the Chef server. Upload Role to Chef Server vipin@laptop:~/chef-repo $ knife role from file web_servers.rb Now, we need to assign a role to a node called server. Assign a Role to Node vipin@laptop:~/chef-repo $ knife node edit server “run_list”: [ “role[web_servers]” ] Saving updated run_list on node server Run the Chef-Client user@server:~$ sudo chef-client …TRUNCATED OUTPUT… [2013-07-25T13:28:24+00:00] INFO: Run List is [role[web_servers]] [2013-07-25T13:28:24+00:00] INFO: Run List expands to [ntp] …TRUNCATED OUTPUT… How It Works Define a role in a Ruby file inside the roles folder of Chef repository. A role consists of a name and a description attribute. A role consists of role-specific run list and role-specific attribute settings. Every node that has a role in its run list will have the role’s run list exacted into its own. All the recipes in the role’s run list will be executed on the node. The role will be uploaded to Chef server using the knife role from file command. The role will be added to the node run list. Running Chef client on a node having the role in its run list will execute all the recipes listed in the role. Print Page Previous Next Advertisements ”;

Chef – Dynamically Configuring Recipes ”; Previous Next Attributes are the key components for dynamically configuring cookbooks. Attributes enable the authors to make the cookbook configurable. By overriding default values set in cookbooks, the user can inject their own values. Step 1 − Create a default file for cookbook attributes and add a default attribute to it. vipin@laptop:~/chef-repo $ subl cookbooks/my_cookbook/attributes/default.rb default[”my_cookbook”][”message”] = ”hello world!” Step 2 − Define the attribute inside the recipe. vipin@laptop:~/chef-repo $ subl cookbooks/<Cookbook Name>/recipes/default.rb message = node[”my_cookbook”][”message”] Chef::Log.info(“** Saying what I was told to say: #{message}”) Step 3 − Uploading the modified cookbook. vipin@laptop:~/chef-repo $ knife cookbook upload my_cookbook Uploading my_cookbook [0.1.0] Step 4 − Running Chef-Client of the defined node. user@server:~$ sudo chef-client …TRUNCATED OUTPUT… [2013-01-13T20:48:21+00:00] INFO: ** Saying what I was told to say: hello world! …TRUNCATED OUTPUT… Working Method Chef loads all attributes from the attribute file before it executes them. The attributes are stored with the node object. One can access all the attributes stored with the node object within recipes and retrieve their current values. Chef has a restricted structure starting from the default being the lowest, then comes normal (which is aliased with the set) and then overrides. The attribute level set in the recipe has precedence over the same level set in an attribute file. Overriding Attribute at the Node and Environment Level Attribute defined in roles or environment have the highest precedence. Step 1 − Create a role. vipin@laptop:~/chef-repo $ subl roles/german_hosts.rb name “german_hosts” description “This Role contains hosts, which should print out their messages in German” run_list “recipe[my_cookbook]” default_attributes “my_cookbook” => { “message” => “Hallo Welt!” } Step 2 − Upload the role to Chef server. vipin@laptop:~/chef-repo $ knife role from file german_hosts.rb Updated Role german_hosts! Step 3 − Assign the role to a node. vipin@laptop:~/chef-repo $ knife node edit server “run_list”: [ “role[german_hosts]” ] Saving updated run_list on node server Step 4 − Run the Chef-Client. user@server:~$ sudo chef-client …TRUNCATED OUTPUT… [2013-01-13T20:49:49+00:00] INFO: ** Saying what I was told to say: Hallo Welt! …TRUNCATED OUTPUT… Print Page Previous Next Advertisements ”;

Chef – Plain Ruby with Chef DSL ”; Previous Next In Chef, if one needs to create simple recipes one can use resources available in Chef, such as templates, remote_file, and services. However as the recipes become elaborate, one needs advanced techniques, such as conditional statements to execute parts of the recipe on condition. This is the power of mixing plain Ruby with Chef Domain Specific Language (DSL). How to Use It? Start Chef Shell on any of the node in the client mode to be able to access the Chef server. user@server:~$ sudo chef-shell –client loading configuration: /etc/chef/client.rb Session type: client …TRUNCATED OUTPUT… run `help” for help, `exit” or ^D to quit. Ohai2u user@server! Chef> Basic Conditions with Chef DSL Sort nodes by name using plain Ruby. chef > nodes.sort! {|a,b| a.name <=> b.name } => [node[alice],node[server]] Loop through the nodes, printing their operating system. chef > nodes.each do |n| chef > puts n[”os”] chef ?> end linux windows => [node[server], node[alice]] Install multiple Ruby gems using an array, a loop, and string expansion to construct the gem names. chef > %w{ec2 essentials}.each do |gem| chef > gem_package “knife-#{gem}” chef ?> end => [“ec2”, “essentials”] Working Method Chef recipes are Ruby files, which gets evaluated in the context of Chef run. They can contain plain Ruby code such as if statement and loops as well as Chef DSL elements such as resources. Inside the recipe, one can simply declare Ruby variables and assign values to it. Print Page Previous Next Advertisements ”;

Chef – Useful Resources ”; Previous Next The following resources contain additional information on Chef. Please use them to get more in-depth knowledge on this. Useful Links on Chef Chef Website− Official Website of Chef Chef Wiki − Wikipedia Reference for Chef Useful Books on Chef To enlist your site on this page, please drop an email to [email protected] Print Page Previous Next Advertisements ”;

Chef – Knife Setup ”; Previous Next Knife is Chef’s command-line tool to interact with the Chef server. One uses it for uploading cookbooks and managing other aspects of Chef. It provides an interface between the chefDK (Repo) on the local machine and the Chef server. It helps in managing − Chef nodes Cookbook Recipe Environments Cloud Resources Cloud Provisioning Installation on Chef client on Chef nodes Knife provides a set of commands to manage Chef infrastructure. Bootstrap Commands knife bootstrap [SSH_USER@]FQDN (options) Client Commands knife client bulk delete REGEX (options) knife client create CLIENTNAME (options) knife client delete CLIENT (options) knife client edit CLIENT (options) Usage: C:/opscode/chef/bin/knife (options) knife client key delete CLIENT KEYNAME (options) knife client key edit CLIENT KEYNAME (options) knife client key list CLIENT (options) knife client key show CLIENT KEYNAME (options) knife client list (options) knife client reregister CLIENT (options) knife client show CLIENT (options) Configure Commands knife configure (options) knife configure client DIRECTORY Cookbook Commands knife cookbook bulk delete REGEX (options) knife cookbook create COOKBOOK (options) knife cookbook delete COOKBOOK VERSION (options) knife cookbook download COOKBOOK [VERSION] (options) knife cookbook list (options) knife cookbook metadata COOKBOOK (options) knife cookbook metadata from FILE (options) knife cookbook show COOKBOOK [VERSION] [PART] [FILENAME] (options) knife cookbook test [COOKBOOKS…] (options) knife cookbook upload [COOKBOOKS…] (options) Cookbook Site Commands knife cookbook site download COOKBOOK [VERSION] (options) knife cookbook site install COOKBOOK [VERSION] (options) knife cookbook site list (options) knife cookbook site search QUERY (options) knife cookbook site share COOKBOOK [CATEGORY] (options) knife cookbook site show COOKBOOK [VERSION] (options) knife cookbook site unshare COOKBOOK Data Bag Commands knife data bag create BAG [ITEM] (options) knife data bag delete BAG [ITEM] (options) knife data bag edit BAG ITEM (options) knife data bag from file BAG FILE|FOLDER [FILE|FOLDER..] (options) knife data bag list (options) knife data bag show BAG [ITEM] (options) Environment Commands knife environment compare [ENVIRONMENT..] (options) knife environment create ENVIRONMENT (options) knife environment delete ENVIRONMENT (options) knife environment edit ENVIRONMENT (options) knife environment from file FILE [FILE..] (options) knife environment list (options) knife environment show ENVIRONMENT (options) Exec Commands knife exec [SCRIPT] (options) Help Commands knife help [list|TOPIC] Index Commands knife index rebuild (options) Node Commands knife node bulk delete REGEX (options) knife node create NODE (options) knife node delete NODE (options) knife node edit NODE (options) knife node environment set NODE ENVIRONMENT knife node from file FILE (options) knife node list (options) knife node run_list add [NODE] [ENTRY[,ENTRY]] (options) knife node run_list remove [NODE] [ENTRY[,ENTRY]] (options) knife node run_list set NODE ENTRIES (options) knife node show NODE (options) OSC Commands knife osc_user create USER (options) knife osc_user delete USER (options) knife osc_user edit USER (options) knife osc_user list (options) knife osc_user reregister USER (options) knife osc_user show USER (options) Path-Based Commands knife delete [PATTERN1 … PATTERNn] knife deps PATTERN1 [PATTERNn] knife diff PATTERNS knife download PATTERNS knife edit [PATTERN1 … PATTERNn] knife list [-dfR1p] [PATTERN1 … PATTERNn] knife show [PATTERN1 … PATTERNn] knife upload PATTERNS knife xargs [COMMAND] Raw Commands knife raw REQUEST_PATH Recipe Commands knife recipe list [PATTERN] Role Commands knife role bulk delete REGEX (options) knife role create ROLE (options) knife role delete ROLE (options) knife role edit ROLE (options) knife role env_run_list add [ROLE] [ENVIRONMENT] [ENTRY[,ENTRY]] (options) knife role env_run_list clear [ROLE] [ENVIRONMENT] knife role env_run_list remove [ROLE] [ENVIRONMENT] [ENTRIES] knife role env_run_list replace [ROLE] [ENVIRONMENT] [OLD_ENTRY] [NEW_ENTRY] knife role env_run_list set [ROLE] [ENVIRONMENT] [ENTRIES] knife role from file FILE [FILE..] (options) knife role list (options) knife role run_list add [ROLE] [ENTRY[,ENTRY]] (options) knife role run_list clear [ROLE] knife role run_list remove [ROLE] [ENTRY] knife role run_list replace [ROLE] [OLD_ENTRY] [NEW_ENTRY] knife role run_list set [ROLE] [ENTRIES] knife role show ROLE (options) Serve Commands knife serve (options) SSH Commands knife ssh QUERY COMMAND (options) SSL Commands knife ssl check [URL] (options) knife ssl fetch [URL] (options) Status Commands knife status QUERY (options) Tag Commands knife tag create NODE TAG … knife tag delete NODE TAG … knife tag list NODE User Commands knife user create USERNAME DISPLAY_NAME FIRST_NAME LAST_NAME EMAIL PASSWORD (options) knife user delete USER (options) knife user edit USER (options) knife user key create USER (options) knife user key delete USER KEYNAME (options) knife user key edit USER KEYNAME (options) knife user key list USER (options) knife user key show USER KEYNAME (options) knife user list (options) knife user reregister USER (options) knife user show USER (options) Knife Setup In order to set up knife, one needs to move to .chef directory and create a knife.rb inside the chef repo, which tells knife about the configuration details. This will have a couple up details. current_dir = File.dirname(__FILE__) log_level :info log_location STDOUT node_name ”node_name” client_key “#{current_dir}/USER.pem” validation_client_name ”ORG_NAME-validator” validation_key “#{current_dir}/ORGANIZATION-validator.pem” chef_server_url ”https://api.chef.io/organizations/ORG_NAME” cache_type ”BasicFile” cache_options( :path => “#{ENV[”HOME”]}/.chef/checksums” ) cookbook_path [“#{current_dir}/../cookbooks”] In the above code, we are using the hosted Chef server which uses the following two keys. validation_client_name ”ORG_NAME-validator” validation_key “#{current_dir}/ORGANIZATION-validator.pem” Here, knife.rb tells knife which organization to use and where to find the private key. It tells knife where to find the users’ private key. client_key “#{current_dir}/USER.pem” The following line of code tells knife we are using the hosted server. chef_server_url ”https://api.chef.io/organizations/ORG_NAME” Using the knife.rb file, the validator knife can now connect to your organization’s hosted Opscode. Print Page Previous Next Advertisements ”;

Chef – Test Kitchen Setup ”; Previous Next Test Kitchen is Chef’s integrated testing framework. It enables writing test recipes, which will run on the VMs once they are instantiated and converged using the cookbook. The test recipes run on that VM and can verify if everything works as expected. ChefSpec is something which only simulates a Chef run. Test kitchen boots up real node and runs Chef on it. Step 1 − Install test kitchen Ruby gem and test kitchen vagrant gem to enable test kitchen to use vagrant for spinning up test. $ gem install kitchen $ gem install kitchen-vagrant Step 2 − Set up test kitchen. This can be done by creating .kitchen.yml in the cookbook directory. driver_plugin: vagrant driver_config: require_chef_omnibus: true platforms: – name: ubuntu-12.04 driver_config: box: opscode-ubuntu-12.04 box_url: https://opscode-vm.s3.amazonaws.com/vagrant/opscode_ ubuntu-12.04_provisionerless.box suites: – name: default run_list: – recipe[minitest-handler] – recipe[my_cookbook_test] attributes: { my_cookbook: { greeting: ”Ohai, Minitest!”} } In the above code, one part defines that vagrant needs to spin up the VMs and it defines that you want Omnibus to install Chef on the target node. The second part defines which platform you want to test the cookbooks. Vagrant will always create and destroy new instances. You do not have to fear about the side effects with vagrant VMs you spin up using Vagrant file. Test kitchen can be considered as a temporary environment that helps to run and test cookbooks in a temporary environment that is similar to production. With test kitchen on, one can make sure that the given piece of code is working, before it is actually getting deployed on to testing, preproduction, and production environment. This feature of test kitchen is followed by many organizations as a set before putting the cookbooks in an actual working environment. Test Kitchen Workflow Following are the steps involved in Test Kitchen Workflow. Creating a Cookbook Using Chef Use the following code to create a cookbook. $ chef generate cookbook motd_rhel Installing Cookbook Gems: Compiling Cookbooks… Recipe: code_generator::cookbook * directory[C:/chef/cookbooks/motd_rhel] action create – create new directory C:/chef/cookbooks/motd_rhel * template[C:/chef/cookbooks/motd_rhel/metadata.rb] action create_if_missing – create new file C:/chef/cookbooks/motd_rhel/metadata.rb – update content in file C:/chef/cookbooks/motd_rhel/metadata.rb from none to d6fcc2 (diff output suppressed by config) * template[C:/chef/cookbooks/motd_rhel/README.md] action create_if_missing – create new file C:/chef/cookbooks/motd_rhel/README.md – update content in file C:/chef/cookbooks/motd_rhel/README.md from none to 50deab (diff output suppressed by config) * cookbook_file[C:/chef/cookbooks/motd_rhel/chefignore] action create – create new file C:/chef/cookbooks/motd_rhel/chefignore – update content in file C:/chef/cookbooks/motd_rhel/chefignore from none to 15fac5 (diff output suppressed by config) * cookbook_file[C:/chef/cookbooks/motd_rhel/Berksfile] action create_if_missing – create new file C:/chef/cookbooks/motd_rhel/Berksfile – update content in file C:/chef/cookbooks/motd_rhel/Berksfile from none to 9f08dc (diff output suppressed by config) * template[C:/chef/cookbooks/motd_rhel/.kitchen.yml] action create_if_missing – create new file C:/chef/cookbooks/motd_rhel/.kitchen.yml – update content in file C:/chef/cookbooks/motd_rhel/.kitchen.yml from none to 49b92b (diff output suppressed by config) * directory[C:/chef/cookbooks/motd_rhel/test/integration/default/serverspec] action create – create new directory C:/chef/cookbooks/motd_rhel/test/integration/default/serverspec * directory[C:/chef/cookbooks/motd_rhel/test/integration/helpers/serverspec] action create – create new directory C:/chef/cookbooks/motd_rhel/test/integration/helpers/serverspec * cookbook_file [C:/chef/cookbooks/motd_rhel/test/integration/helpers/serverspec/spec_helper.rb] action create_if_missing – create new file C:/chef/cookbooks/motd_rhel/test/integration/helpers/serverspec/spec_helper.rb – update content in file C:/chef/cookbooks/motd_rhel/test/integration/helpers/serverspec/spec_helper.rb from none to d85df4 (diff output suppressed by config) * template [C:/chef/cookbooks/motd_rhel/test/integration/default/serverspec/defaul t_spec.rb] action create_if_missing – create new file C:/chef/cookbooks/motd_rhel/test/integration/default/serverspec/default_spec.rb – update content in file C:/chef/cookbooks/motd_rhel/test/integration/default/serverspec/default_spec.rb from none to 3fbdbd (diff output suppressed by config) * directory[C:/chef/cookbooks/motd_rhel/spec/unit/recipes] action create – create new directory C:/chef/cookbooks/motd_rhel/spec/unit/recipes * cookbook_file [C:/chef/cookbooks/motd_rhel/spec/spec_helper.rb] action create_if_missing – create new file C:/chef/cookbooks/motd_rhel/spec/spec_helper.rb – update content in file C:/chef/cookbooks/motd_rhel/spec/spec_helper.rb from none to 587075 (diff output suppressed by config) * template [C:/chef/cookbooks/motd_rhel/spec/unit/recipes/default_spec.rb] action create_if_missing – create new file C:/chef/cookbooks/motd_rhel/spec/unit/recipes/default_spec.rb – update content in file C:/chef/cookbooks/motd_rhel/spec/unit/recipes/default_spec.rb from none to ff3b17 (diff output suppressed by config) * directory[C:/chef/cookbooks/motd_rhel/recipes] action create – create new directory C:/chef/cookbooks/motd_rhel/recipes * template[C:/chef/cookbooks/motd_rhel/recipes/default.rb] action create_if_missing – create new file C:/chef/cookbooks/motd_rhel/recipes/default.rb – update content in file C:/chef/cookbooks/motd_rhel/recipes/default.rb from none to c4b029 (diff output suppressed by config) * execute[initialize-git] action run – execute git init . * cookbook_file[C:/chef/cookbooks/motd_rhel/.gitignore] action create – create new file C:/chef/cookbooks/motd_rhel/.gitignore – update content in file C:/chef/cookbooks/motd_rhel/.gitignore from none to 33d469 (diff output suppressed by config) * execute[git-add-new-files] action run – execute git add . * execute[git-commit-new-files] action run – execute git commit -m “Add generated cookbook content” Following is the Created Cookbook Structure as an output of the above code. Test Kitchen Configuration File .kitchen.yaml file driver: name: vagrant provisioner: name: chef_zero # verifier: # name: inspec # format: doc platforms: – name: ubuntu-14.04 suites: – name: default run_list: – recipe[motd_rhel::default] attributes: Drivers − It specifies the software which manages the machine. Provisioner − It provides specification on how Chef runs. We are using chef_zero because it enables to mimic a Chef server environment on the local machine. This allows to work with node attributes and Chef server specifications. Platform − This specifies the target operating system. Suites − It defines what one wants to apply on the virtual environment. Here, you define multiple definition. It is the location where you define the run list, which specifies which recipe to run and in which sequence we need to run. Running the Commands in Sequence Kitchen List $ kitchen list Instance Driver Provisioner Verifier Transport Last Action ubuntu-1404 Vagrant ChefZero Busser Ssh <Not Created> Kitchen Create $ kitchen create —–> Starting Kitchen (v1.4.2) —–> Creating <default-centos-72>… Bringing machine ”default” up with ”virtualbox” provider… ==> default: Box ”opscode-centos-7.2” could not be found. Attempting to find and install… default: Box Provider: virtualbox default: Box Version: >= 0 ==> default: Box file was not detected as metadata. Adding it directly… ==> default: Adding box ”opscode-centos-7.2” (v0) for provider: virtualbox default: Downloading: https://opscode-vmbento.s3.amazonaws.com/vagrant/virtualbox/ opscode_centos-7.1_chefprovisionerless.box[…] Vagrant instance <default-centos-72> created. Finished creating <default-centos-72> (3m12.01s). —–> Kitchen is finished. (3m12.60s) Kitchen Converge $ kitchen converge —–> Converging <default-centos-72>… Preparing files for transfer Preparing dna.json Resolving cookbook dependencies with Berkshelf 4.0.1… Removing non-cookbook files before transfer Preparing validation.pem Preparing client.rb —–> Chef Omnibus installation detected (install only if missing) Transferring files to <default-centos-72> Starting Chef Client, version 12.6.0 resolving cookbooks for run list: [“motd_rhel::default”] Synchronizing Cookbooks: – motd_rhel (0.1.0) Compiling Cookbooks… Converging 1 resources Recipe: motd_rhel::default (up to date) Running handlers: Running handlers complete

Chef – Environment ”; Previous Next Chef helps in performing environment specific configuration. It is always a good idea to have a separate environment for development, testing, and production. Chef enables grouping nodes into separate environments to support an ordered development flow. Creating an Environment Creation of environment on the fly can be done using the knife utility. Following command will open a Shell’s default editor, so that one can modify the environment definition. vipin@laptop:~/chef-repo $ knife environment create book { “name”: “book”, “description”: “”, “cookbook_versions”: { }, “json_class”: “Chef::Environment”, “chef_type”: “environment”, “default_attributes”: { }, “override_attributes”: { } } Created book Testing a Created Environment vipin@laptop:~/chef-repo $ knife environment list _default book List Node for All Environments vipin@laptop:~/chef-repo $ knife node list my_server _default Environment Each organization will always start with at least a single environment called default environment, which is always available to the Chef server. A default environment cannot be modified in anyway. Any kind of changes can only be accommodated in the custom environment that we create. Environment Attributes An attribute can be defined in an environment and then used to override the default settings in the node. When the Chef client run takes place, then these attributes are compared with the default attributes that are already present in the node. When the environment attributes take precedence over the default attributes, Chef client will apply these settings and values when the Chef client run takes place on each node. An environment attribute can only be either default_attribute or override_attribute. It cannot be a normal attribute. One can use default_attribute or override_attribute methods. Attribute Type Default − A default attribute is always reset at the start of every Chef client run and have the lowest attribute precedence. Override − An override attribute is always reset at the start of every Chef client run and has a higher attribute precedence than default, force_default and normal. An override attribute is most often defined in the recipe but can also be specified in an attribute file for a role or for an environment. Order of Applying an Attribute Print Page Previous Next Advertisements ”;