Linux

How to set your Domain name in Linux

Resume to set a domain name in Linux concepts: FQDN (Fully Qualified Domain Name) eg: hostname = server1 // FQDN = server1.example.com 1. First add FQDN to your hostname in /etc/hosts file. # cat /etc/hosts 10.120.68.23 server1.example.com server1 confirm the FQDN issue the following command: # hostname -f server1.example.com 2.1. Configure domain name (Red Hat RHEL, Fedora and CentOS) From these path add the parameters needs vi /etc/sysconfig/network DOMAINNAME=<domainname> vi /etc/sysctl.conf kernel.domainname = <domainname> 2.2. figure domain name ( Ubuntu, Debian) #vi /etc/hostname server1 Then restart the service: ...

Add your app into the Gnome Desktop Menu

I’ve been looking for a encryptation app open source, to encrypt my files into Cloud with a touch of off-online control, and I found this nice app called Cryptomator. I downloaded the extension .Appimage, so the following instruction I will explain is how to set the .appimage into the app menu in Gnome. Download the Cryptomator by the link above. Set the permission below: #chmod a+x cryptomator-1.4.15-x86_64.AppImage The try to execute the file by a shell terminal or just double click on it ( to confirm it was downloaded fined) ...

How to create a docker-compose.service

Here are the steps I made to set a service into my Fedora server to start/stop my Docker-compose (Wikijs) Why I decided to use a docker-compose into a Linux VM machine? —> for make it more stable, faster,portable, isolated, etc. First I stared using Docker for Windows and it was a little bit unstable and not quite easy to handled, so when I switched to Docker compose into a Fedora VM and in that point it was a huge different(I do not recommend to use Docker in Windows); I use a Vmware hypervisor ( in the office we use it ). ...

Closing opened ports on Linux (Fedora 29)

Using the Nmap to list our opened port in our machine, how described the official website: Nmap “..is an utility for network discovery and security auditing..” Regarding CUPS from the official website: “is an open source printing system developed by Apple Inc. for macOSÂ® and other UNIXÂ®-like operating systems. CUPS uses the Internet Printing Protocol (IPP) to support printing to local and network printers.” By default we have the cups service running in the system’s startup we could check out issue the following commands: ...

Setup Grafana in Raspbian (Raspberrypi)

The below post is a simple explanation I did time ago, if you want further info and better explanation about how to setup a monitoring system into your Raspberripy please go to here. Raspbian version:9.8 $ uname -r 4.14.98-v7+ $ uname -m armv7l Version installed on my RasPi: Grafana v6.0.2 (3f4c2e7) Download Grafana package for your correct Raspi ARM $sudo dpkg -i grafana_6.1.3_armhf.deb $systemctl start grafana-server $systemctl status grafana-server then you will see from the status propmt the address=0.0.0.0:3000 msg="HTTP Server Listen" logger=http.server address=0.0.0.0:3000 To check the site is working go through localhost:3000 ...

Create a job using crontab

To automate tasks or create some monitoring job we can use the older and efficient tool the “CronJob”. For our example, I’ve created a simple script to detect the cache memory and clean it if raise to a condition then send a notification by mail. Library used: exim4 (mail server) or ssmtp (mail server). Both uses the same “mail” command. Script: # grab the buff/cache memory mem="$(free -m | grep 'Mem:' | awk '{print $6}')" if (( $mem > 350 )) then echo 'wooo is more than 250M' echo 3 | sudo tee /proc/sys/vm/drop_caches echo 'cache dropped' echo "Memory buff/cache cleaned last value:" $mem | mail -s "cache_memory" target_mail@local.com else echo 'be cool man, memory lower' fi script path: /user/Documents/script/memory ...

Disable live-restore to run Docker Swarm

The following instruction is a solution when you got an error response with live-restore using Docker Swarm in Fedora 28 or highter $ docker swarm init Error response from daemon: --live-restore daemon configuration is incompatible with swarm mode That’s not possible to enable Live-restore and Swarm-mode together. First make sure that the SElinux is Permissive or Disabled. $ sestatus SELinux status: enabled SELinuxfs mount: /sys/fs/selinux SELinux root directory: /etc/selinux Loaded policy name: targeted Current mode: permissive Mode from config file: enforcing Policy MLS status: enabled Policy deny_unknown status: allowed Memory protection checking: actual (secure) Max kernel policy version: 31 Then remove the –live-restore line from the /etc/sysconfig/docker ...

Enable "Kubectl" auto-completion in the Shell (Linux)

When you’ve done the SDK installation in your Linux workstation. list the components you have installed, then you will see the full list additional components from gcp SDK: gcloud components list gcloud components install <COMPONENT_ID> gcloud components install kubectl Then follow the instruction from the kubernetes official documentation, check the “bash-completion” and finally issue the command below: echo "source <(kubectl completion bash)" >> ~/.bashrc Even you can go directly through your .bashrc (sudo) to add manually, it should look like: ...