Linux Engineer Technology

01. Command alias function, set a permanent valid command alias
The role of aliases: Create a shorter, better-written command word for a lengthy command line that requires frequent use
# VIM/ETC/BASHRC
Alias aliases = ' Actual command line '

02. Red Hat 7 Series Firewall service preset security zone public, trusted, drop functions and features
Public zone: The default zone, only allow SSH services for native, others deny
Trusted zone: Any access to this machine is allowed
Drop zone: Any packets that access this computer will be rejected

What is SELinux and how does it affect the Linux system?
SELinux mechanism: A kernel-based security enhancement mechanism that provides a set of documents, processes, and other objects in a Linux system
Pre-set protection rules
Impact on Linux systems: In a forced protected mode, even root cannot violate its protection rules (unless changing
or avoidance rules)

04. Quickly add a new virtual host when you configure the HTTPD Web server
1) Create a separate configuration file for each virtual host, put it in the/etc/httpd/conf.d/directory, configure the file
Name ends with. conf
2) Configure <virtualhost IP Address: Port number >. .. </VirtualHost> section tags, where statements are used
ServerName Specify the site name, use DocumentRoot to specify the Web page directory
3) Then restart the httpd service

05. Conditions for erecting a secure Web site based on httpd
Installing the Mod_ssl module package
Provide the available Web site certificates, keys, and deploy to the correct location
Modify the/etc/httpd/conf.d/ssl.conf configuration file to specify the site name, Web directory, certificate, and path to the key

06. Dynamic Web page and static Web page difference, based on httpd to support PHP program, Python program needs to have the conditions
Static Web page: The Web page file accessed by the browser is the Web file Dynamic Web page provided by the server: the Web page file accessed by the browser is a dynamically generated Web page file by the program specified by the server.
Support PHP Program: Install httpd, PHP package
Support for Python programs: Install HTTPD, MOD_WSGI packages, and add program call aliases when configuring a site
(Wsgiscriptalias)

What is NFS referring to, the main difference from EXT4, XFS
Nfs,network File System: Document resources reside on other hosts ' directories, network filesystem
EXT4, XFS: The document resource is stored on a device that has a well-formatted partition on the computer, and the local file system

08. What are shell scripts and what are the benefits of using shell scripts?
Shell script: A collection of a number of command-line, able to complete a specific task, can be executed in order to repeat the execution of files
The benefits of Shell scripting: process repetitive tasks, simplify complex tasks, and automate tasks that are manually intervened
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Linux Engineer Technology