The previous article has explained how to install the phpMyAdmin application on Linux using the Apache web server. This article explains how to configure phpMyAdmin using nginx on Ubuntu.

Problem

How to install phpMyAdmin with nginx on Ubuntu?

Solution

Follow the steps below to install phpMyAdmin with Nginx on Ubuntu:

1. Update repo

Use the command below to update the Ubuntu repo:

sudo apt update -y

2. Install MariaDB

Next, install the MariaDB database using the command:

sudo apt install mariadb-server mariadb-client -y

Once finished, use the command below to change the root password in MariaDB:

sudo mysql_secure_installation

Then check whether the database is up or not using the command below:

sudo systemctl status mariadb

3. Install PHP

Install PHP by using the command below:

sudo apt install php php-fpm php-mysql php-cli php-curl php-gd php-mbstring php-xml php-zip -y

Then check the version of PHP that you just installed by using the command below:

php -v

Usually, when installing PHP, the Apache package will also be installed on the server. Therefore, delete Apache using the command:

sudo apt remove apache2-* -y

4. Install phpMyAdmin

Use the command below to install phpMyAdmin:

sudo apt install phpmyadmin -y

At the time of installation, there are several pop-ups that you must answer, such as the selection of the web server you are using, as shown in the image below:

Just select the button Ok, then the process of installation will continue. A few seconds later, there will be a pop-up as below to insert the phpMyAdmin in the database:

Select the button Yes, and there’s a pop-up to enter the password for the user phpmyadmin in the database as in the picture below:

Enter the password you want, select the OK button, and there will be another pop-up to confirm the password as in the image below:

Enter the same password and select the Ok button, then the phpMyAdmin installation process will continue until completion.

5. Install nginx

Install nginx by using the command below:

sudo apt install nginx -y

After that, configure Nginx so that it can be integrated with phpMyAdmin. Copy the default file using the command below:

sudo cp /etc/nginx/sites-available/default /etc/nginx/sites-available/default.ori

Then in the default file, copy the script below:

server {
    listen 80;
    server_name _;
    root /var/www/html;
    index index.php index.html;

    location / {
        try_files $uri $uri/ =404;
    }

    location /phpmyadmin {
        root /usr/share/;
        index index.php;

        location ~ ^/phpmyadmin/(.+\.php)$ {
            try_files $uri =404;
            root /usr/share/;
            fastcgi_pass unix:/run/php/php8.3-fpm.sock;
            fastcgi_index index.php;
            fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
            include fastcgi_params;
        }

        location ~* ^/phpmyadmin/(.+\.(css|js|jpg|jpeg|gif|png|ico|html|xml|txt))$ {
            root /usr/share/;
        }
    }
}

ls -l /run/php/

After that, use the command below to check whether the nginx configuration has errors or not:

sudo nginx -t

If there are no errors, then you can run the command below to reload nginx:

sudo systemctl reload nginx

6. Open phpMyAdmin

Open your browser and type:

http://ip_server/phpmyadmin

Then there should be a display like below:

Enter the database username and password, for example, using the user phpmyadmin with the password that you created when installing phpMyAdmin, then there will be a display like the one below:

Note

If you want the phpMyAdmin application to be more secure, you can look at this page.

References

markaicode.com
linuxbabe.com
hostman.com

I want to see the metric values ​​of my MariaDB database.

Problem

How to display MariaDB database metric values?

Solution

As far as I know, there are 2 tools that you can use to display the values of metrics on your MariaDB database.

1. mariadb-report

This tool is built into MariaDB, so when you install the MariaDB database or mariadb-client on your server, this tool will automatically be installed on your server. In general, use the format below to run this command:

mariadb-report --user=username --password your_password

If you want to display MariaDB database metrics using the root user, then use the command below:

mariadb-report --user=root --password

Enter the password for the root user, and a display will appear as below:

If you want to put the results into a file, you can use the command below:

mariadb-report --user=root --password --outfile /tmp/metric.txt

Enter the password, and the results will be entered into the /tmp/metric.txt file. 

2. mysqlmonitor

This is a simple bash script created to give system administrators and database administrators a fast summary of MySQL metrics. It presents essential metrics such as InnoDB buffer utilization, query efficiency, and system memory, accompanied by concise descriptions of each parameter. To run this script, you must create MariaDB credentials in the my.cnf file, because if not, there will be an error like the one below:

Copy the script below and insert it into the my.cnf file:

[client]
user=username
password=your_password

To download and run the script, run the commands below:

curl -O https://raw.githubusercontent.com/haydenjames/mysqlmonitor-script/main/mysqlmonitor.sh && 
chmod +x mysqlmonitor.sh && 
./mysqlmonitor.sh

There will be a display like the image below:

From the image above, you can see that the results from the mysqlmonitor tool are more concise than the mariadb-report tool. To exit this tool, press the q key.

Note

If you want detailed metric results, then you can use the mariadb-report tool. However, if you want more concise metrics, you can use the mysqlmonitor tool.

References

linuxblog.io
mariadb.com
github.com

The previous article explained the mysqltuner script to provide recommendations to increase MariaDB performance. This article will explain the primary-tuning script, which is an alternative or may also be an addition to providing recommendations for MariaDB.

Problem

How to install and run tuning-primer?

Solution

The primary-tuning script was created by Matthew Montgomery using a bash script to provide recommendations against a MySQL/MariaDB database. This script takes information from “SHOW STATUS LIKE…” and “SHOW VARIABLES LIKE…” to produce recommendations for tuning server variables. To download this script, use the command below:

git clone https://github.com/mattiabasone/tuning-primer.git

Go to the primary-tuning folder and permit so that the script can be run:

chmod +x tuning-primary.sh

Then, run the command below to run the primary-tuning script:

./tuning-primer.sh

There will be a display like the image below:

Press Enter, then you have to enter your username and password so that this script can access your MariaDB database, as in the image below:

After that, the script will display recommendations as in the image below:

Note

Because this script was created in 2018 and there has been no update, there are several errors that occur where on lines 1482 and 1483 (see first image) in the netstat command where at this time (November 2025), the netstat command has been changed to ss and also the password is written as plain text which is very dangerous if known by the unauthorized user.

References

linuxblog.io
github.com

If you have a MariaDB database, then you definitely want the performance of the database to improve. Therefore, you should have done several configurations to achieve your goals. There is a script called mysqltuner that you can use to improve the performance of your MariaDB database by providing recommendations.

Problem

How to install and run mysqltuner?

Solution

mysqltuner is a Perl script designed to quickly assess a MySQL setup and implement changes to enhance performance and stability. It supports ~300 indicators for MySQL/MariaDB/Percona Server in this latest version and is actively maintained, supporting many configurations such as Galera Cluster, TokuDB, Performance schema, Linux OS metrics, InnoDB, MyISAM, Aria, and so on. To download it, you can run the command:

git clone https://github.com/major/MySQLTuner-perl.git

Or use the commands below:

wget http://mysqltuner.pl/ -O mysqltuner.pl
wget https://raw.githubusercontent.com/major/MySQLTuner-perl/master/basic_passwords.txt -O basic_passwords.txt
wget https://raw.githubusercontent.com/major/MySQLTuner-perl/master/vulnerabilities.csv -O vulnerabilities.csv

To run this script, you must have Perl installed on your server. So, to run this script, you can use the command (if you download mysqltuner using git, you have to go to the MySQLTuner-perl folder):

perl mysqltuner.pl

Or you permit this script to be executed by using the command:

chmod +x mysqltuner.pl
./mysqltuner.pl

After you run the command, there will be a display as below:

Enter the username and password, and if there is no error, mysqltuner displays your MariaDB state as shown in the image below:

And at the end, mysqltuner will recommend that your MariaDB improve its performance:

Note

If you want to run mysqltuner with the verbose option, use the command below:

perl mysqltuner.pl --verbose

If you want to display Maximum Output Information around MySQL, like display database(s) and table(s) on mysqltuner, use the command below:

perl mysqltuner.pl --buffers --dbstat --idxstat --sysstat --pfstat --tbstat

Use the command below to use CVE(Common Vulnerabilities and Exposures) in mysqltuner:

perl mysqltuner.pl --cvefile=vulnerabilities.csv

Use the command below to save the results from mysqltuner in a file without displaying it on the screen:

perl mysqltuner.pl --silent --outputfile /tmp/result_mysqltuner.txt

To update mysqltuner, run the command below:

perl mysqltuner.pl --checkversion --updateversion

References

mysqltuner.com
github.com
hevodata.com

I would like to know who is running crontab on the Linux server.

Problem

How to display all crontabs running using a Bash script?

Solution

By default, run the command below if you want to display the crontab command:

crontab -l

However, if you want to display another user, for example, user john, use the command below:

sudo crontab -l -u john

If you want to see all users running crontab, then you can run the command below:

Ubuntu/Debian

ls -l /var/spool/cron/crontabs

RockyLinux/AlmaLinux/RHEL/CentOS

ls -l /var/spool/cron/

Use the command below if you want to see all users running crontab and display each user’s crontab at the same time:

awk -F: '$3>=1000 || $1=="root" {print $1}' /etc/passwd |
while read u; do
    if sudo crontab -l -u "$u" &>/dev/null; then
        echo
        echo "=== $u ==="
        sudo crontab -l -u "$u" | grep -v '^#' | sed '/^\s*$/d'
        echo ""
    fi
done

If you want the result of the above command to be entered as a CSV file, then run the command below:

echo "user,cron_entry" > all_user_crontab.csv; \
awk -F: '$3>=1000||$1=="root"{print $1}' /etc/passwd | while read u; do \
    if sudo crontab -l -u "$u" &>/dev/null; then \
        sudo crontab -l -u "$u" | \
        grep -v '^[[:space:]]*#' | grep -v '^[[:space:]]*$' | \
        while read line; do \
            echo "$u,\"$line\"" >> all_user_crontab.csv; \
        done; \
    fi; \
done

However, if you want to display all crontabs, whether run by the user or the Linux system, then you can use the command below:

#!/bin/bash

clean_output() {
    grep -v '^[[:space:]]*#' | grep -v '^[[:space:]]*$'
}

echo "=== SYSTEM CRONTABS ==="
echo ""

# Main crontab system
if [[ -f /etc/crontab ]]; then
    echo "--- /etc/crontab ---"
    clean_output < /etc/crontab
    echo ""
fi

# Cron.d directory
if [[ -d /etc/cron.d ]]; then
    echo "--- /etc/cron.d/ ---"
    for f in /etc/cron.d/*; do
        [[ -f "$f" ]] || continue
        echo "File: $f"
        clean_output < "$f"
        echo ""
    done
fi

# Cron.daily, cron.hourly, cron.weekly, cron.monthly
for dir in daily hourly weekly monthly; do
    path="/etc/cron.$dir"
    if [[ -d "$path" ]]; then
        echo "--- /etc/cron.$dir/ ---"
        # List script names only (normally no '#' inside)
        ls -1 "$path"
        echo ""
    fi
done

echo "=== USER CRONTABS ==="
echo ""

# All user in /etc/passwd
for user in $(cut -f1 -d: /etc/passwd); do
    uid=$(id -u "$user" 2>/dev/null)
    [[ $? -ne 0 ]] && continue
    if [[ $uid -lt 1000 && $user != "root" ]]; then
        continue
    fi

    crontab_content=$(sudo crontab -l -u "$user" 2>/dev/null | clean_output)

    if [[ -n "$crontab_content" ]]; then
        echo "--- Crontab for user: $user ---"
        echo "$crontab_content"
        echo ""
    fi
done

And use the script below if you want to insert the result into a CSV file:

#!/bin/bash

OUTPUT="cron_inventory.csv"

echo "type,owner,source,cron_entry" > "$OUTPUT"

filter_clean() {
    grep -v '^[[:space:]]*#' | grep -v '^[[:space:]]*$'
}

#############################################
# SYSTEM CRONTAB
#############################################

if [[ -f /etc/crontab ]]; then
    cat /etc/crontab | filter_clean | while read line; do
        echo "system,root,/etc/crontab,\"$line\"" >> "$OUTPUT"
    done
fi

#############################################
# /etc/cron.d
#############################################

if [[ -d /etc/cron.d ]]; then
    for file in /etc/cron.d/*; do
        [[ -f "$file" ]] || continue
        cat "$file" | filter_clean | while read line; do
            echo "system,root,$file,\"$line\"" >> "$OUTPUT"
        done
    done
fi

#############################################
# cron.daily / cron.hourly / cron.weekly / cron.monthly
#############################################

for dir in daily hourly weekly monthly; do
    path="/etc/cron.$dir"
    if [[ -d "$path" ]]; then
        for script in "$path"/*; do
            [[ -f "$script" ]] || continue
            echo "system,root,$path,$(basename "$script")" >> "$OUTPUT"
        done
    fi
done

#############################################
# USER CRONTABS
#############################################

for user in $(cut -f1 -d: /etc/passwd); do
    uid=$(id -u "$user" 2>/dev/null)
    [[ $? -ne 0 ]] && continue
    if [[ $uid -lt 1000 && $user != "root" ]]; then
        continue
    fi

    crontab -l -u "$user" 2>/dev/null | filter_clean | while read line; do
        echo "user,$user,crontab,\"$line\"" >> "$OUTPUT"
    done
done

echo "== CSV generated: $OUTPUT =="

Note

By displaying users who use crontab on a Linux server, you can save your time and effort investigating if there are commands running at a certain time on that server.

References

stackoverflow.com
unix.stackexchange.com
cyberciti.biz

By default, MariaDB uses port 3306. I want to change the default port to another port for security reasons.

Problem

How to change MariaDB port?

Solution

To see the default MariaDB port, you can use the command below:

sudo ss -ptuln | grep mariadb

Or you run the query below:

show variables like 'port';

From the images above, you can see MariaDB is using port 3306. If you want to change the port from 3306 to 4306, for example, then in the file /etc/mysql/mariadb.conf.d/50-server.cnf if you are using Ubuntu, add the item below:

port                    = 4306

sudo find / -type f -name "*server.cnf"

Then restart mariadb using the command:

sudo systemctl restart mariadb

After that, you can check the MariaDB port by using one of the commands above, and the MariaDB port should have changed according to the port you want, as shown in the image below:

Note

If you have changed the default port of MariaDB from 3306 to 4306, for example, then you don’t need to write the port in the Linux command to access MariaDB if you access from localhost:

But, if you access MariaDB from another host, you have to write the option for the port, like in the picture below:

References

geeksforgeeks.org
stackoverflow.com
tecmint.com

By default, PostgreSQL uses port 5432. But for security’s sake, I want to change the default port to another one.

Problem

How to change the default port in PostgreSQL?

Solution

If you want to see the port used by PostgreSQL, you can see it in the postgresql.conf file by using the command (I’m using Ubuntu distro and PostgreSQL version 18):

cat /etc/postgresql/18/main/postgresql.conf | grep 'port ='

Or you can use the command below to see the PostgreSQL port:

sudo ss -ptuln | grep postgres

Or you can use the query in this post to see the port used by PostgreSQL:

SHOW PORT;

From the images above, you can see that PostgreSQL uses port 5432. If you want to change the PostgreSQL port to port 6543, for example, then go to the /etc/postgresql/18/main/postgresql.conf file if you use the Ubuntu distro and PostgreSQL version 18, and change the port value from 5432 to 6432.

sudo find / -type f -name "*postgresql.conf"

Then restart PostgreSQL using the command:

sudo systemctl restart postgresql

After that, you can check the PostgreSQL port by using one of the commands above, and the PostgreSQL port should have changed according to the port you want as shown in the image below:

Note

If you have changed the default port of PostgreSQL from 5432 to 6432, for example, then you don’t need to write the port in the Linux command to access PostgreSQL if you access from localhost: 

But, if you access PostgreSQL from another host, you have to write the option for the port, like in the picture below:

References

stackoverflow.com
dbvis.com
geeksforgeeks.org