There are two ways to install Golang in Ubuntu. But to install the latest one, I highly recommend to download the binary file from the official go website.

golang website downloadDownload Golang binary file$ sudo wgetExtract the files from the downloaded tar file.$ sudo tar xvzf go1.15.6.linux ...


Add the following entry in “http{}” block on the/etc/nginx/nginx.conflog_format debug_val_format "$debug_val";In the “server{}” block , for example, set the following entries.#For debuggingset $debug_val "value is :$valiable";access_log/var/log/nginx/debug_val.log debug_val_f ...


Install MySQL Yum Repository

Example: Download “mysql80-community-release-el8-1.noarch.rpm“


Install “mysql80-community-release-el8-1.noarch.rpm“

yum install mysql80-community-release-el8-1.noarch.rpm

Add “sudo”, if needed.

Check Repo list# yum ...


Mongoose is Object – Database modeling library with mongodb and node.js.

mongoosejs websiteHow to set “OR” and “AND” query in find methods?

You can set “OR” operator in the find method like the following syntax.


Example 1. Use “$or&# ...

Visual Studio Code

What is “Prettier”

Prettier is a code formatter and can work on Visual Studio Code as an extension.

By using this tool, your code is automatically formatted when you save it.

How to install Prettier on VSCode.

You can install it on > > .

Search “Prettier& ...


If GUI is not installed on Ubuntu, you need to setup Network configuration by editing some files.

Here is an example of how to set static IP address on Ubuntu 20.04.Move the default configuration file.$ mv/etc/netplan/00-installer-config.yaml/etc/netplan/00-installer-config.yaml.bkupEdit Netwo ...


Complex filter “orderBy” and “equalTo” doesn’t work

For example, if you send query with the simple REST API like ,


You may encounter the following Errors;

Error Message 1.

constraint index field must be a json ...


“Nested VT-x/AMD-V” can not be changed by default

On page of the Virtual Box 6.x, “Enable Nested VT-x/AMD-V” is grayed out and cannot be changed.

Solution : Execute a VBoxManage command

Move to the directory where Virtual Box is installed on. Then execute the followin ...


If you want to know how to setup a basic HTTP reverse proxy server with NGINX, please visit “How To Setup HTTP Reverse Proxy with Nginx” at first.

In this article, we assumed that the basic setup for a basic http reverse proxy is already finished.

Obtain Certificates for HTTP ...


Problem: MySQL 5.7 is down.

MySQL server is shutdown unexpectedly once a month. It happened when we updated MySQL to 5.7.24. In the/var/mysql.log, the following logs are shown. What is wrong?

2020-07-09T05:54:41.056589Z 0 Giving 0 client threads a chance to die gracefully2020-07-09T05:54:41.05 ...


If you want to know how to install NGINX, please visit “How To Install Nginx on Ubuntu 20.04” at first.

Setup HTTP Reverse Proxy!

Let’s try to setup a HTTP reverse proxy server with Nginx as the following picture.

Understand Nginx’s configuration files.

NginxR ...

Visual Studio Code

Adjust Indent

You can adjust indents manually with Alt + Shift + F keys.

But if you don’t want to type them every time, I recommend the auto indent feature.

Move to >>. Then, Enter “formaton”. You can see the following setting items.

Check the each items.

Ope ...

Development,React Native

If you haven’t read “Which is Better? ExpoCLI Tool or React Native CLI“, please visit this post at first.

Start Expo CLI Tool

After Install, start Expo CLI with the “npm start” command.


npm start>@ start C:\test-project>expo startStarting proje ...


Option 1. Use the “/etc/localtime” file

Mounting the “localtime” file is the most popular way to change the timezone of containers. Here is an example.

Example: By using host server’s “/etc/localtime” file, change container’s timezone.

sudo ...


Port Forwarding Feature on Docker

As you know, on Docker, you can set port forwarding between host server and containers with the following command.

$ docker container run -p :

Example: Create Nginx container. In this case the packets coming to 80 port on the host server will be forwarded to ...


Check Current Timezone$ timedatectl


$ timedatectl Local time: Wed 2020-07-01 01:35:04 UTC Universal time: Wed 2020-07-01 01:35:04 UTC RTC time: Wed 2020-07-01 01:35:05 Time zone: Etc/UTC (UTC, +0000)System clock synchronized: yes NTP service: active RTC in local TZ: noChange Timezone


Nginx is one of the most popular and highest performance web servers in the world.
In most cases it is used a web server or HTTP/HTTPS reverse proxy. Also recently it can become a proxy of UDP stream.

Install Nginx on Ubuntu 20.04sudo apt updatesudo apt install nginxCheck If Your Nginx is ...


Create Swap File

Here, as an example, create a 400MB swap file “/swpfile”.

dd if=/dev/zero of=/swapfile bs=1M count=1048mkswap/swapfilechmod 600/swapfile

After the swap file “/swpfile” is created, enable the file.


You can check the status with the ...


Install Samba Server on Ubuntu 20.04

Install the Samba from Ubuntu repository with following commands in your Ubuntu terminal.

sudo apt upgradesudo apt install samba

After install, check status and version.

smbd --versionsystemctl status smbdsystemctl status nmbd


Edit/etc/sam ...


Basically, there are 2 options to control containers with shells without SSH login.

Option 1. Use -t (pseudo-tty) option without ssh

Example: Create a new nginx container named “webnode“, and run it interactively. By using “-t” option that simulates a terminal, you ca ...