Introduction to Chef detailed introduction to Chef installation and use of Chef

Posted by cac818 on Wed, 22 Dec 2021 17:25:13 +0100

This article is a reference to the official website. If you have any misunderstanding, please correct it. If you have any questions, please leave a message to discuss them together

Installation deployment

chef server

Official documents: https://docs.chef.io/server/install_server/
Important prerequisites: modify your own hostname (the value I configured is chefserver, and both workstation and node machines need to be able to parse), synchronize the clock, and close the firewall

Download the installation package and upload it to the server for installation
Download address: https://downloads.chef.io/chef-server/
```
[root@chefworkstation ~] rpm -Uvh chef-server-core-12.19.31-1.sles12.x86_64.rpm
```
Configure and start service: Chef server CTL command help document: https://docs.chef.io/server/ctl_chef_server/
```
[root@chefworkstation ~] chef-server-ctl reconfigure
```

Create administrator user

[root@chefworkstation ~] mkdir -p /path/to
[root@chefworkstation ~] chef-server-ctl user-create janedoe Jane Doe janed@example.com 'abc123' --filename /path/to/janedoe.pem

Create the organization and associate the user janedoe to the admin security group of the organization

[root@chefworkstation ~] chef-server-ctl org-create 4thcafe 'Fourth Cafe, Inc.' --association_user janedoe --filename /path/to/4thcafe-validator.pem

In order to facilitate management, I create a cw user and add cw to the admin Group. cw will be used in the subsequent installation of workstation PEM file

[root@chefworkstation ~] chef-server-ctl user-create cw chef workstation cw@example.com '111111' --filename /path/to/cw.pem
[root@chefworkstation ~] chef-server-ctl org-user-add 4thcafe cw --admin

chef workstation

Official documents: https://docs.chef.io/workstation/install_workstation/
Important prerequisites: modify your own hostname, be able to parse the chefserver (the hostname of the server machine), configure clock synchronization, close the firewall, and have a minimum memory of 4G

Install package

[root@chefworkstation ~] wget https://packages.chef.io/files/stable/chef-workstation/21.2.278/el/8/chef-workstation-21.2.278-1.el7.x86_64.rpm
[root@chefworkstation ~] yum localinstall chef-workstation-21.2.278-1.el7.x86_64.rpm
[root@chefworkstation ~] chef -v
Chef Workstation version: 21.2.278
Chef Infra Client version: 16.10.8
Chef InSpec version: 4.26.4
Chef CLI version: 3.1.1
Chef Habitat version: 1.6.181
Test Kitchen version: 2.10.0
Cookstyle version: 7.8.0

Check the installation directory. The default workstation is installed under / opt

[root@chefworkstation opt] ls /opt/
chef-workstation

Set ruby in Chef Workstation as the default ruby for linux

[root@chefworkstation ~] echo 'eval "$(chef shell-init bash)"' >> ~/.bashrc

Restart a terminal (restart an xshell) and execute which ruby

[root@chefworkstation ~] which ruby
/opt/chef-workstation/embedded/bin/ruby

Create a repository warehouse to store local cookbook s and other resources (Chef repo in the command represents the name of the repository you want to create). Finally, a repository will be created in the directory where the command is executed. To facilitate management, I choose to put it in the same directory as workstation

[root@chefworkstation ~] cd /opt/
[root@chefworkstation ~] chef generate repo chef-repo

(chef command help document: https://docs.chef.io/workstation/ctl_chef/#chef-generate-repo)
Finally, the directory structure is as follows

[root@chefworkstation opt] ll /opt/
drwxr-xr-x 6 root root 161 Aug 13 10:08 chef-repo
drwxr-xr-x 7 root root 186 Aug 13 09:46 chef-workstation
[root@chefworkstation opt] tree chef-repo/
chef-repo/
├── chefignore
├── cookbooks
│   ├── example
│   │   ├── attributes
│   │   │   └── default.rb
│   │   ├── metadata.rb
│   │   ├── README.md
│   │   └── recipes
│   │       └── default.rb
│   └── README.md
├── data_bags
│   ├── example
│   │   └── example_item.json
│   └── README.md
├── LICENSE
├── policyfiles
│   └── README.md
└── README.md
7 directories, 11 files

Use the knife configure command to create a credentials file (~ /. chef / directory) to communicate with the server (use knife config show to view it after creation)
The command requires two parameters: Chef Server URL and Client Name. My parameters are as follows:
Chef Server URL: https://chefserver/organizations/4thcafe (chefserver is the hostname of the server machine, which needs to be resolved in the hosts of workstation, and 4thcafe is the name of the organization created on the server)
Client Name: CW (user created on server)
```
[root@chefworkstation opt] knife configure
#View content
[root@chefworkstation cookbooks] knife config show
Loading from credentials file /root/.chef/credentials
chef_server_url: https://chefserver/organizations/4thcafe
client_key:      /root/.chef/cw.pem
config_file:
log_level:       warn
log_location:    STDERR
node_name:       cw
profile:         default
```
Copy the pem file of user cw on server to workstation ~ / Chef path, view directory structure
```
[root@chefworkstation opt] ll ~/.chef/
-rw-r--r-- 1 root root   36 Aug 13 10:08 chef_guid
-rw-r--r-- 1 root root  133 Aug 13 10:35 credentials
-rw-r--r-- 1 root root 1674 Aug 13 10:52 cw.pem
[root@chefworkstation opt]
```
credentials: the configuration file of the knife command (similar to nginx.conf). For detailed file interpretation, refer to: https://docs.chef.io/workstation/config_rb/
cw.pem: run the command on workstation, and the background completes the corresponding changes by calling the API of server, CW PEM for API service validation

Verify whether the communication between workstation and server is normal

#Since the server uses a self signed certificate, you need to add a knife SSL fetch in the workstation
[root@chefworkstation opt] knife ssl fetch
#Check all client s. If the returned results are similar to the following, it means that the workstation can communicate with the server normally
[root@chefworkstation opt] knife client list
4thcafe-validator

chef client installation

Official documents: https://docs.chef.io/workstation/knife_bootstrap/
Important premise: modify your own hostname, be able to parse the chefserver (the hostname of the server machine), configure clock synchronization, and close the firewall

Chef client installation refers to installing the client program chef client on the managed node. This operation is completed by executing commands on the workstation
Execute the command on the workstation to install the client (modify the IP in the command and the login account and password of the server)

#192.168.16.12: node IP
#chefnode2: hostname of node
#root: the user name to log in to the node server
#1: The password corresponding to the user name of the node server
[root@chefworkstation opt]knife bootstrap 192.168.16.12 -N chefnode -U root -P 1

Check whether the node is successfully installed in the workstation

[root@chefworkstation opt] knife node list
chefnode

[root@chefnode chef] ll /opt/chef/
drwxr-xr-x 2 root root   204 Aug 12 13:21 bin
drwxr-xr-x 7 root root    67 Aug 12 13:21 embedded
-rw-r--r-- 1 root root 35962 Jul 28 03:24 LICENSE
drwxr-xr-x 2 root root  8192 Aug 12 13:21 LICENSES
-rw-r--r-- 1 root root  7002 Jul 28 03:25 version-manifest.json
-rw-r--r-- 1 root root  3500 Jul 28 03:25 version-manifest.txt
[root@chefnode chef]

Detailed explanation of knife command: https://docs.chef.io/workstation/knife/

Actual combat: Quick Start

Next, I will explain how to write recipe, create files, folders and install software packages. The overall process is as follows
workstation local create repo - > create cookbook in repo - > write recipe - > execute recipe locally (not required) - > upload cookbook to server - > node execute recipe

Create a repo locally: myrepo

[root@chefworkstation cookbooks] cd /opt/
[root@chefworkstation opt] chef generate repo myrepo

Create local cookbook: mycookbook

[root@chefworkstation opt] cd myrepo/cookbooks/
[root@chefworkstation cookbooks] chef generate cookbook mycookbook

Write recipe. For specific syntax format and parameter description, refer to:
recipe syntax format: https://docs.chef.io/resource/
All resource types and parameters: https://docs.chef.io/resources/

[root@chefworkstation cookbooks] cd mycookbook/
[root@chefworkstation mycookbook] vim recipes/default.rb
 Write the following notes( action (space between and)
#Create a folder using directory resource
directory '/home/resource_directory' do
    action :create
end

#Create a file using file resource
file '/home/resource_directory/resource_file' do
    content 'This is created by chef!'
end

#Executing linux commands using bash resource
bash 'excute command' do
  cwd '/home/'
  code <<-EOH
    mkdir -p resource_bash
    echo "This is created by bash resource!" >> resource_bash_file.txt
  EOH
end
#Use package resource to install telnet package
package 'telnet'  do
    action :install
end

Execute recipe locally in workstation, and pay attention to whether the directory is correct

[root@chefworkstation mycookbook] pwd
/opt/myrepo/cookbooks/mycookbook
[root@chefworkstation mycookbook] chef-client -z -o mycookbook

Check whether the corresponding folders, files are created, and software packages are installed

[root@chefworkstation mycookbook] ll /home/
total 4
drwxr-xr-x 2 root root  6 Aug 19 11:40 resource_bash
-rw-r--r-- 1 root root 34 Aug 19 11:40 resource_bash_file.txt
drwxr-xr-x 2 root root 27 Aug 19 11:40 resource_directory
[root@chefworkstation mycookbook] rpm -qa |grep telnet
telnet-0.17-66.el7.x86_64

So far, we have learned to write recipe s locally in the workstation, use various built-in resource s to complete file creation, software package installation and other operations, and then upload the cookbook to the server and execute it on the node to make the node reach the same state
```
[root@chefworkstation mycookbook] knife cookbook upload mycookbook --cookbook-path /opt/myrepo/cookbooks/
Uploading mycookbook     [0.1.0]
Uploaded 1 cookbook.
```
Optional operation: the path of the cookbook needs to be specified in the command. We can write this parameter to the configuration file, and there is no need to manually transfer parameters in the command in the future
```
[root@chefworkstation mycookbook] vim /root/.chef/credentials
#Add the following line: please refer to the credentials file mentioned above for specific parameters that can be added
cookbook_path   = '/opt/myrepo/cookbooks/'
```
Here you may have some questions. What is the purpose of knife? The official introduction is as follows:
knife is a command-line tool that provides an interface between a local chef-repo and the Chef Infra Server
Knife is a command-line tool that provides an interface for local repo and server interaction. A simple understanding is that the execution of knife commands is related to the server most of the time. For specific usage of knife, please refer to the knife official website for details
To view which cookbook s are available on the server:
```
[root@chefworkstation mycookbook] knife cookbook list
mycookbook             0.1.0
```

The next step is to ask node to execute the recipe just uploaded, but now node doesn't know what it needs to execute. We need to tell it what it should execute (run list)

#Edit the run list of chefnode machine and tell it to execute the default recipe of mycookbook, - e VI is the specified editor. You can also use vim or other tools
#For convenience, this can also be written in the configuration file: create XXX in the credentials file and the same directory D folder, and then create XXX in it RB file, write the following line
#knife[:editor]      = 'vi'
[root@chefworkstation mycookbook] knife node edit chefnode -e vi

The modified contents are as follows (after modification: wq save, the same as the local vi file)

	{
  "name": "chefnode",
  "chef_environment": "_default",
  "normal": {
    "tags": [

    ]
  },
  "policy_name": null,
  "policy_group": null,
  "run_list": [
  "recipe[mycookbook::default]"
]

}

Then you can log in to the node machine and execute run list
```
#It can be executed in any directory of the node machine. After playing, check whether the files and folders are created and whether the telnet package is installed.
[root@chefnode home] chef-client
```
So far, the process operation has been completed. For more information about role, environment, policy file, etc., please refer to the official website: https://docs.chef.io/

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