In some situation, we may want to delegate a sudo capability to Linux users or groups without completely giving them full access to the operating system. We can achieve this by using User_Alias inside the /etc/sudoers configuration file. I will share the simple settings that I used in my RHEL server. ## Sudoers allows particular users to run various commands as ## the root user, without needing the root password. ## ## Examples are provided at the bottom of the file for collections ## of related commands, which can then be delegated out to particular ## users or groups....

I would like to share the Golang’s build flag to remove the source path (GOPATH) from panic stack trace output. In production environments or commercial projects it is sometimes not ideal to display the source path because of privacy, security or other reasons. Below is an example of a stack trace output that reveals the GOPATH location which is located inside the developer’s home directory. In this case /home/johnpili/go/ panic: Aw, snap goroutine 1 [running]: main....

In this blog post, I’ll share how to generate text to image in Go programming language (Golang). I have a previous and similar blog post using Python. You can check that post here I created this application to generate images of my Linux configuration files or source code snippets and share it via WhatsApp or other messaging platforms. Another reason is to generate featured images for my social media posts in Twitter, Facebook or LinkedIn....

Systemd is a Linux software suite that handles system services (daemon) and timers; it enables you to start, stop and restart your application using systemctl command. It can also start your application during operating systems boot-up sequence. Note that you will need to have root or sudo privileges for this operation. To create a systemd unit file, create a service file inside the directory /etc/systemd/system/. The filename must end with ....

Setting up a static IP address in your RHEL or CentOS is simple. Prerequisite This how-to guide requires that you have administrative access to the Linux operating system. Steps Inside the RHEL Operating system, open the terminal and head to /etc/sysconfig/network-scripts. Using ls command, you can see the available network devices in the directory. cd /etc/sysconfig/network-scripts ls Use a text editor to edit the specific network device configuration...

In some MySQL installation in Ubuntu. You cannot login as root because it is not configured to use mysql_native_password. In this post, I will teach you how to enable mysql_native_password. Log in to MySQL via terminal with sudo mysql -u root Once inside MySQL, we will need to change the default plugin authentication to mysql_native_password and set a password for root. mysql> ALTER USER [email protected] IDENTIFIED BY 'password'; mysql> exit You can now login in MySQL as root using the password you set....

You may need to setup an SSH keys or environment variables to your Jenkins installations. One of the easy way to do this is to setup those environment variables inside the jenkins user account. If you installed Jenkins in CentOS or Ubuntu via YUM or APT; These package managers will setup a jenkins user account without login capability and shell. That means you cannot simply SSH to it. Using your other Linux account you can login as jenkins using the command snippet below....

You build your first Golang web application and running in a remote server via SSH. The problem with that is once the SSH session is terminated it also kill any running programs associated with that SSH session. Using nohup solves this problem but I think this is okay during development and testing phase. A better way to deploy your Golang application into a Linux production environment is create a systemd entry making it as a daemon program....

To randomly create a time.Sleep in Golang you can use the code snippet below. You may want to simulate a load in your web server and have an arbitrary seconds or minutes before getting the reply. package main import ( "log" "math/rand" "time" ) func main() { rand.Seed(time.Now().UnixNano()) for i := 0; i < 15; i++ { delta := rand.Intn(6 + 1) // randomly generates numbers 1 to 6 time....

In response to this facebook post. I created a simple bus seat reservation user interface using Vue.js and SVG. I started by preparing an SVG image of the bus seat and then render the SVG elements using Javascript (VueJS). You can use a raster image (sprite) for this but I prefer to use vector graphics (SVG) because it allows me to control the stroke and background color programmatically. The bus seat vector image looks like this...