It’s been awhile since we decided to remotely update the servers. Not even the servers, but the scripts on those servers. And why not take the opportunity to create a post for our Cloud consulting and services series, detailing exactly how why use Chef for infrastructure management!
We use self-compiled scripts for content update (for real-time debugging). Using the server-client principle, that is the initializer script and the executable script on the servers. But since there are a lot of servers, making changes to a script on each server will take ages.
So, we begin.
Requirements:
1. We already have the OS with updated packages.
2. We have a FQDN name.
3. Curl and wget should already be installed.
Server installation:
1. Go to https://www.opscode.com/chef/install
2. Click tab “Chef Server”
3. Select the operating system and the architecture
4. Select Chef version
5. Install the package
rpm -ivh https://opscode-omnibus-packages.s3.amazonaws.com/el/6/x86_64/chef-server-11.1.3-1.el6.x86_64.rpm
Configure Chef server 11.*. Run command
# chef-server-ctl reconfigure
It will install and set up the required packages itself
Then we stop the web-server, if any, and run the verification script:
# chef-server-ctl test
After the test, go to:
# https://FQDN-OR-IP-OF-CHEF-SERVER
Note: Default UserName/Password: admin/[email protected]
Setting up the WorkStation:
Run command (on Linux like)
# curl -L https://www.opscode.com/chef/install.sh | bash
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
101 6790 101 6790 0 0 3826 0 0:00:01 0:00:01 —:—:— 12190
Downloading Chef for el…
Installing Chef
warning: /tmp/tmp.KnyQTnqz/chef-.x86_64.rpm: Header V4 DSA/SHA1 Signature, key ID 83ef826a: NOKEY
Preparing… ########################################### [100%] 1:chef ########################################### [100%] Thank you for installing Chef!
After the installation is complete, verify the client is installed
# chef-client -v
Chef: 11.6.0
Create a Chef directory
Copy Cert Keys from Chef Server to Workstation User Folder
$ mkdir ~/.chef $ scp [email protected]-server:/etc/chef-server/admin.pem ~/.chef $ scp [email protected]-server:/etc/chef-server/chef-validator.pem ~/.chef
Now, configure the client using the “knife” command
$ knife configure -i
Overwrite /root/.chef/knife.rb? (Y/N) y
Please enter the chef server URL: [https://test.example.com:443] https://chef-server.example.com:443/
Please enter a name for the new user: [root] knife-user1
Please enter the existing admin name: [admin] Enter
Please enter the location of the existing admin’s private key: [/etc/chef-server/admin.pem] ~/.chef/admin.pem
Please enter the validation clientname: [chef-validator] Please enter the location of the validation key: [/etc/chef-server/chef-validator.pem] ~/.chef/chef-validator.pem
Please enter the path to a chef repository (or leave blank):
Creating initial API user…
Please enter a password for the new user:
Created user[knife-user1] Configuration file written to /root/.chef/knife.rb
Your “Knife config” (knife.rb) will look like this:
$ cat ~/.chef/knife.rb
log_level :info
log_location STDOUT
node_name ‘knife-user1’
client_key ‘/root/.chef/knife-user1.pem’
validation_client_name ‘chef-validator’
validation_key ‘/root/.chef/admin.pem’
chef_server_url ‘https://chef-server.example.com:443/’
syntax_check_cache_path ‘/root/.chef/syntax_check_cache’
Check our installation by running the respective commands:
$ knife client list
chef-validator
chef-webui
$ knife user list
admin
knife-user1
Installing the node:
Run command (on Linux like)
# curl -L https://www.opscode.com/chef/install.sh | bash
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
101 6790 101 6790 0 0 3826 0 0:00:01 0:00:01 —:—:— 12190
Downloading Chef for el…
Installing Chef
warning: /tmp/tmp.KnyQTnqz/chef-.x86_64.rpm: Header V4 DSA/SHA1 Signature, key ID 83ef826a: NOKEY
Preparing… ########################################### [100%] 1:chef ########################################### [100%] Thank you for installing Chef!
Create Chef directory
# mkdir /etc/chef
Copy Chef Server Validation Cert Keys from Chef Server to our node in “/etc/chef”:
# scp [email protected]:/etc/chef-server/chef-validator.pem /etc/chef
Run the command and register yourself in Chef Server:
# chef-client -S https://FQDN-OR-IP-OF-CHEF-SERVER -K /etc/chef/chef-validator.pem
Once the client is verified, we have to create a file in “client.rb” in directory “/etc/chef”.
# vi /etc/chef/client.rb
log_level :info
log_location STDOUT
chef_server_url ‘https://FQDN-OR-IP-OF-CHEF-SERVER’
Check successful registration of the node
On WorkStation, run command:
# knife node list
And on the server in web-interface
# https://FQDN-OR-IP-OF-CHEF-SERVER
Run the client:
# chef-client # chef-client -l debug (In case if you want to debug)
Create a simple Cookbook and write a Recipe there
Log in to WorkStation:
# vi /root/.chef/knife.rb
cookbook_path [ ‘/usr/local/src/chef/cookbooks’ ]
Create a directory for Cookbook:
# mkdir -p /usr/local/src/chef/cookbooks
Now, create a simple Cookbook
# knife cookbook create cookbook-test
Go to the directory
# cd /usr/local/src/chef/cookbooks # tree cookbook-test
cookbook-test/
├── attributes
├── CHANGELOG.md
├── definitions
├── files
│ └── default
├── libraries
├── metadata.rb
├── providers
├── README.md
├── recipes
│ └── default.rb
├── resources
└── templates
└── default
Now, let’s create a recipe for the new group (system-admins) and user “sanjay”.
# cat /usr/local/src/chef/cookbooks/cookbook-test/recipes/default.rb
#
# Cookbook Name:: cookbook-test
# Recipe:: default
#
# Copyright 2016, YOUR_COMPANY_NAME
#
# All rights reserved — Do Not Redistribute
#
group «system-admins» do
gid 1001
end
user «sanjay» do
comment «Sanjay User»
shell «/bin/bash»
home «/home/sanjay»
gid «system-admins»
uid 1002
supports :manage_home => true
password «$1$QwuUa80Z$KZkYq8CqICVyIsK1tHZ7s0»
end
To upload cookbooks to the server, do the following:
# knife upload cookbooks
Note: this will upload all cookbooks to the server
To upload a particular book to the server:
# knife upload cookbooks cookbook-test
Now, add our recipe to run_list
# knife node list
node1.example.com
node2.example.com
node3.example.com
# knife node run_list add node1.example.com cookbook-test
node1.example.com:
run_list: recipe[cookbook-test
Now, log in to the machine node1.example.com, and run command
# chef-client
[2016-10-25T04:47:36-07:00] INFO: Forking chef instance to converge…
Starting Chef Client, version 11.6.2
[2016-10-25T04:47:36-07:00] INFO: *** Chef 11.6.2 ***
[2016-10-25T04:47:37-07:00] INFO: Run List is
] [2016-10-25T04:47:37-07:00] INFO: Run List expands to [cookbook-test] [2016-10-25T04:47:37-07:00] INFO: Starting Chef Run for node1.example.com
[2016-10-25T04:47:37-07:00] INFO: Running start handlers
[2016-10-25T04:47:37-07:00] INFO: Start handlers complete.
resolving cookbooks for run list: [«cookbook-test»] [2016-10-25T04:47:37-07:00] INFO: Loading cookbooks [cookbook-test] Synchronizing Cookbooks:
[2016-10-25T04:47:37-07:00] INFO: Storing updated cookbooks/cookbook-test/recipes/default.rb in the cache.
[2016-10-25T04:47:37-07:00] INFO: Storing updated cookbooks/cookbook-test/metadata.rb in the cache.
[2016-10-25T04:47:37-07:00] INFO: Storing updated cookbooks/cookbook-test/README.md in the cache.
[2016-10-25T04:47:37-07:00] INFO: Storing updated cookbooks/cookbook-test/CHANGELOG.md in the cache.
— cookbook-test
Compiling Cookbooks…
Converging 1 resources
Recipe: cookbook-test::default
* group[system-admins] action create[2016-10-25T22:23:38-07:00] INFO: Processing group[system-admins] action create (cookbook-test::default line 9)
(up to date)
* user[sanjay] action create[2016-10-25T04:47:37-07:00] INFO: Processing user[sanjay] action create (cookbook-test::default line 9)
(up to date)
[2016-10-25T04:47:37-07:00] INFO: Chef Run complete in 0.48225768 seconds
[2016-10-25T04:47:37-07:00] INFO: Running report handlers
[2016-10-25T04:47:37-07:00] INFO: Report handlers complete
Chef Client finished, 0 resources updated
To create one more sendmail installation and run recipe, type on WorkStation
# vim /usr/local/src/chef/cookbooks/cookbook-test/recipes/sendmail.rb
package 'sendmail' do action :install end service 'sendmail' do action [ :enable,:start ] end
Upload the cookbook
# knife upload cookbooks cookbook-test
Run on the node:
# chef-client
Recipe: cookbook-test::sendmail
* package[sendmail] action install[2016-10-25T22:05:22-07:00] INFO: Processing package[sendmail] action install (cookbook-test::sendmail line 1)
[2016-10-25T22:06:14-07:00] INFO: package[sendmail] installing sendmail-8.14.4-8.el6 from base repository
— install version 8.14.4-8.el6 of package sendmail
* service[sendmail] action enable[2016-10-28T04:12:10-07:00] INFO: Processing service[sendmail] action enable (system-users::sendmail line 5)
(up to date)
* service[sendmail] action start[2016-10-28T04:12:11-07:00] INFO: Processing service[sendmail] action start (system-users::sendmail line 5)
[2016-10-28T04:12:11-07:00] INFO: service[sendmail] started
— start service service[sendmail]
This is how Chef works. The official site contains a large amount of information about writing recipes and setting up the program.
