How to run your first Docker container on Linux? (Hello World Example)

The Redis6 cluster must be created with redis-cli--cluster. It requires a minimum of 3 masters and 3 slaves, a total of 6 nodes. The client port and the corresponding cluster bus port (10000) must be opened. Correct configuration but blocked ports is a common cause of failure.

The most common and reliable way to import SQL files into MySQL is the command line tool mysql, which supports cross-platform, high efficiency and stability, and is suitable for files of all sizes. It can also be executed in the client through the source command, or using graphical tools such as phpMyAdmin and MySQL Workbench.

Linux systems need to use third-party tools for security scanning; lynis is suitable for lightweight local auditing, openvas must be deployed with Docker, nmap and nessus cannot be automatically connected, and the effectiveness of scanning depends on credentials, settings and feed updates.

The most reliable way is to use the iplinkshow command, because it is compatible with old and new kernels, has clear output, and does not confuse virtual interfaces; the MAC address is located after the link/ether line and can be accurately extracted with grep.

The key is not "latest" but "matching": the corresponding MySQL version needs to be selected according to the application framework (such as SpringBoot2.x/3.x, Django4.2) and driver version to avoid compatibility issues such as authentication plug-ins, sorting rules, and proxy tools. For production environments, the 8.0.33LTS version is preferred.

uname-r is the most accurate and quick way to obtain the current kernel version number. It only outputs the release field such as 6.1.0-22-amd64, without redundant information, which is convenient for script parsing; other commands such as uname-v, uname-a or /proc/version have their own uses but are not specifically used for version extraction.

Using sudoaptinstallbuild-essential is the fastest under Ubuntu/Debian. It automatically installs gcc, g, make, libc6-dev, etc.; only installing gcc will report an error that stdio.h does not exist due to a missing header file.

The main reason why /var/log fills up the disk is that journalctl logs grow indefinitely, logrotate fails, or application logs are not cut. You need to use journalctl --vacuum-size or configure journald.conf restrictions, check logrotate permissions and rules, and clean up hidden log directories such as apt and unattended-upgrades.