Almalinux9.1_en

1.Disabling SELinux First, disable selinux. selinux is a feature that improves auditing and security in Linux, but when enabled, it places considerable restrictions on the behavior of services and on what can be configured. Therefore, it is basically disabled in many cases. ①Disable SELinux while it is activated but no policy is loaded 2.Modernize the system Package updates are performed as soon as possible immediately after OS installation. However, when a dnf update is performed, a kernel update is also performed at the same time. Performing a kernel update may require rebooting the system or stopping services, or worse, a kernel panic may occur and the system may not boot. It is wiser to exclude the kernel from the update. By running dnf -y update with "--exclude=kernel*" behind it kernel can be excluded from the update target.

1. Logwatch ①Install # dnf install logwatch ②Edit configuration file 2. DiCE Whenever the global IP changes, which happens when the network is disconnected or the router is disconnected and rebooted, the dynamic DNS must be accessed to inform the user that the global IP has changed. DiCE does this automatically! 3.Introduce disk usage check script 3.1 Script Creation # cd /var/www/system # vi disk_capacity_check.sh

AlmaLinux 9.0 Install AlmaLinux OS is a project launched by CloudLinux in the US as an alternative to CentOS. Currently, the AlmaLinux OS Foundation is the development parent organization.Following the general availability of Red Hat Enterprise Linux 9.0, AlmaLinux 9.0 was released on May 26, 2022. Like Red Hat Enterprise Linux 9, AlmaLinux 9 utilizes the same package versions as the Linux 5.14 kernel, GCC 11, Python 3.9, and RHEL9. Cockpit web management interface, enhanced kernel live patching, improved container and cloud integration, OpenSSL 3, and other security improvements.

1.Apache2 Install , Virtual Host Configuration 1.1 Apache2 install ①httpd install # dnf -y install httpd 1.3 Virtual Host Settings Assign and configure the domain name [alma.korodes.com] to the document root [/var/www/html/alam.korodes.com] directory for virtual host operation 2. Use of CGI Scripts ①CGI availability check 3. PHP installation and configuration 1.PHP8 Install 4. Digest authentication with Apache2 Since Basic Authentication, a well-known authentication authorization method for http, sends authentication information in plain text, there is a risk of ID and password leakage if the packet is intercepted. On the other hand, Digest Authentication encrypts and transmits authentication informa

clamav (anti-virus software] Install 1.Clam AntiVirus install # dnf -y install clamav clamd clamav-update 2.Clam AntiVirus  Configuration File Edit Mail Server Install 1. Postfix 1.1 Install Install Postfix and build an SMTP server

Mysql8 Install ＃ dnf -y install mysql-server charset.cnf   Create a new one with the following contents WordPress Install 1. Create database for Word Press As an example, assume database [wp_db] database user [wp_user] password [?W123456]

1.Website data backup 1-1.Backup under /var/www/html ①Create backup script file # cd /var/www/system # vi backup_html.sh 2.MySQL database backup ①Create backup script file # cd /var/www/system # vi db_my_backup.sh 3.Restore backup files under html ①Store HTML backup files in "/ (root)" directory 4.Restore Mysql backup file ①Save the database backup file to any directory and （In the example, the directory is "/var/www/backup/db_bak".）Extracting data

1.SSH remote connection SSH is a service for connecting remotely to a server and is basically running immediately after the OS is installed, but the default settings are somewhat insecure. Here we will configure the default settings to increase the security of ssh connections. 1.1 SSH service configuration file changes 2.How to set up a firewall (firewalld) In AlmaLinux, the firewall is set to firewalld by default and is enabled during OS installation. 4.NTP Server Build an NTP server to synchronize the server time with Japan Standard Time

SSH connection with authentication using public key cryptography Create public and private key pairs Create a public/private key pair for a user connecting to a Linux server using OpenSSH. Use ssh-keygen to create the key pair. The creation of a public/private key pair must be done as a user with remote login privileges. If you do not specify the destination and file name, id_ed25519 and id_eed25519.pub will be created in /home/(user name)/.ssh/. On the way, enter the password for the key.

1.FTP Server 1. 1 Vsftpd Install # dnf -y install vsftpd 1.2 Configure Vsftpd Save the unedited vsftpd.conf with .bak 3. File server installation with Samba Build a file server with access rights that requires user authentication with Samba. Installation Procedure ①Create shared folders with access rights that require user authentication ②Accessible group creation ③Creation of users belonging to accessible groups ④Configuration File Editing

1.Obtain an SSL certificate ( Let's Encrypt ) Install the latest open ssl # dnf install openssl-devel 1.1 advance preparation 1.Package management system Snappy installed Since the SSL certificate issuing tool "certbot" of Let's Encrypt is recommended to be installed using "snap" after 2021, install Snapd first.(Can also be installed the traditional way with dnf or yum) 2. Converting Apache to https Install the following just in case # dnf -y install mod_ssl 3. SSL/TLS (Let's Encrypt) settings on the mail server 3.1 Obtaining a certificate for the mail server Obtain a certificate for the mail server, but it cannot be obtained in the same way as above, so the following with the "--standalone" option fails.

Suricata SURICATA IDS/IPS is an open source IDS that monitors communications on the network and detects suspicious traffic. The basic mechanism is signature-based, so it can detect predefined unauthorized communications. Suricata is also characterized by its ability to provide protection as well as detection. 1.advance preparation ①Activate the EPEL Repository # dnf -y install epel-release Tripwire 1.Download and installation # cd /usr/local/src # wget https://rpmfind.net/linux/epel/9/Everything/x86_64/Packages/t/tripwire-2.4.3.7-13.el9.x86_64.rpm # rpm -Uvh tripwire-2.4.3.7-13.el9.x86_64.rpm Chkrootkit ①Download and install chkrootkit # cd /usr/local/src # wget https://launchpad.net/chkrootkit/main/0.55/+download/chkrootkit-0.55.tar.gz # tar xvf chkrootkit-0.55.tar.gz