Install Nagios Plugins on CentOS 8

Installation Nagios plugins from the CentOS 8 repository.

Install epel repository;
# dnf install epel-release

Check Nagios plugins;
# dnf list nagios-plugins-*

Install nrpe agent;
# dnf install nrpe

# dnf install gcc glibc glibc-common make gettext automake autoconf wget openssl-devel

Install Nagios plugins;
# dnf install nagios-plugins-{nt,apt,dbi,dig,dns,fts,log,ntp,rpc,ssh,tcp,ups,disk,load,nrpe,swap,dhcp,disk,hpjd,http,icmp,ircd,ldap,load,mrtg,nrpe,perl,ping,real,smtp,snmp,swap,time,wave,fping,mysql,procs,users,dummy,fping,mailq,mysql,pgsql,procs,users,uptime,breeze,by_ssh,flexlm,nagios,nwstat,oracle,overcr,radius,uptime,cluster,sensors,bonding,cluster,sensors,file_age,mrtgtraf,ide_smart,remove_perfdata}

Nagios plugins will be installed in /usr/lib64/nagios/plugins/ directory;
# ls -1 /usr/lib64/nagios/plugins/

------------------------------------------------------------

Or you can try the second method installing Nagios plugins on CentOS 8;

Install nrpe agent and required programmes;
# dnf install nrpe gcc glibc glibc-common make gettext automake autoconf wget openssl-devel

Download plugins;
# wget https://nagios-plugins.org/download/nagios-plugins-2.2.1.tar.gz

Unpack the plugins;
# tar -xvzf nagios-plugins.org/download/nagios-plugins-2.2.1.tar.gz

# cd nagios-plugins-2.2.1

Define the user and group to use;
# ./configure --with-nagios-user=nagios --with-nagios-group=nagios

Compile the software;
# make
# make install

Nagios plugins are installed in /usr/local/nagios/libexec/ directory;
# ls /usr/local/nagios/libexec/

Create Let's Encrypt Certificate Authority (CA), SSL Certificate in openSUSE Leap 15.x

If you're running apache2 web server in openSUSE Leap 15.x,
create a virtual host config file named /etc/apache2/conf.d/mydomain.example.com.conf

1. Configure apache2 for https:

# vim /etc/apache2/conf.d/mydomain.example.com.conf

 <VirtualHost *:443> 
 DocumentRoot "/srv/www/htdocs/owncloud" 
 ServerName mydomain.example.com 
 SSLEngine On 
 SSLCertificateFile /etc/certbot/live/mydomain.example.com/fullchain.pem 
 SSLCertificateKeyFile /etc/certbot/live/mydomain.example.com/privkey.pem 
 <Directory "/srv/www/htdocs/owncloud"> 
 DirectoryIndex index.html info.php index.php 
 Options FollowSymLinks 
 AllowOverride All 
 Require all granted 
 </Directory> 
 </VirtualHost> 

----------------------------------------

# systemctl restart apache2

----------------------------------------

2. Install certboot:

# zypper in certbot python-certbot python-certbot-apache

----------------------------------------

3. Configure data for certboot:

# vim /etc/certbot/cli.ini

    rsa-key-size = 4096
    server = https://acme-v01.api.letsencrypt.org/directory
    email = mailaddress@something.com
    domain = mydomain.example.com
    authenticator = webroot
    webroot-path = /srv/www/htdocs/owncloud

----------------------------------------

3.1. Configure data for letsencrypt:

# vim /etc/letsencrypt/cli.ini

    rsa-key-size = 4096
    server = https://acme-v01.api.letsencrypt.org/directory
    email = mailaddress@something.com
    authenticator = webroot
    webroot-path = /srv/www/htdocs/owncloud
    domain = mydomain.example.com

----------------------------------------

4. Create cert:

# certbot --authenticator webroot --installer apache
# certbot --apache

# systemctl stop apache2
# systemctl start apache2

----------------------------------------

5. Auto renew cert with cron, every 30 days in 2:00 AM:

# crontab -e

# SSL certificates renew
0 2 1 * *  /usr/bin/certbot renew

----------------------------------------

How to manually delete old kernel on Ubuntu, Mint, Debian...

Open command line, and enter:

$ sudo uname -a
$ sudo dpkg --list | grep linux-image
$ sudo dpkg --purge linux-image{,-extra}-4.x.x-xxx-generic
$ sudo apt update && apt upgrade && apt autoremove

KDE mount USB device fails at OpenSuse

KDE mount USB device fails at OpenSuse

An error occured while accesiing , the system responded: An unspecified error has occured. An read ACL for if 1000 to failed: invalid argument

$ sudo mkdir -p /run/media/my_user
$ sudo chown my_user:users /run/media/my_user
$ sudo chmod 775 /run/media/my_user

Disable Network Manager on Mint

$ sudo stop network-manager
$ echo "manual" | sudo tee /etc/init/network-manager.override
$ sudo vi /etc/NetworkManager/NetworkManager.conf
$ sudo vi /etc/network/interfaces

# The loopback network interface
auto lo
iface lo inet loopback

# network interface not managed by Network Manager
allow-hotplug eth0
iface eth0 inet static
address 192.168.1.10
netmask 255.255.255.0
gateway 182.168.1.1
dns-nameservers 8.8.8.8

$ nmcli dev status

Games for KDE OpenSUSE

# zypper install bomber bovo granatier kapman katomic kblackbox kblocks kbounce kbreakout kdiamond kfourinline kgoldrunner kigo killbots kiriki kjumpingcube klickety klines kmahjongg kmines knavalbattle knetwalk kolf kollision konquest kpat kreversi kshisen ksirk ksnakeduel kspaceduel ksquares ksudoku ktuberling kubrick lskat palapeli picmi kajongg

Dolphin - Super User Mode

Application Menu >
    Dolphin >
        Edit Applications >
            New Item >
                General >
                    Name: Dolphin - Super User Mode
                    Command: dbus-launch dolphin -qwindowtitle "%c" "%u"

                Advanced > Run as a different user

Change vendor and update all packages from Packman repo in OpenSuse 15.0

Add all Packman repo into OpenSuse Leap 15.0:
$ sudo zypper ar -f http://packman.jacobs-university.de/suse/openSUSE_Leap_15.0/ Packman-repo-15.0

Show all repos in OpenSuse:
$ sudo zypper repos

$ sudo zypper install --from [repository] [package]

In my case update gstreamer-plugins-bad-lang package from Packman repo:
$ sudo zypper install --from Packman-repo-15.0 gstreamer-plugins-bad-lang

Change vendor and update all packages from Packman repo:
$ sudo zypper dup --from Packman-repo-15.0

Refresh repo, update packages and upgrade and clean OpenSuse:
$ sudo zypper ref && sudo zypper update -y && sudo zypper dup -y && sudo zypper clean

Allow CUPS to install printer in Chrome browser

This procedure will allow CUPS to install printer in Chrome browser. If Chrome shows unauthorized message, do the following.

CUPS > Administration > Add printer on Chrome shows:
Unauthorized
Enter your username and password or the root username and password to access this page. If you are using Kerberos authentication, make sure you have a valid Kerberos ticket.



Create a copy of the CUPS config file:
# cp /etc/cups/cupsd.conf /etc/cups/cupsd.conf-BAK



Edit CUPS:
# vim /etc/cups/cupsd.conf

Change:

AuthType Default
Require user @SYSTEM
Order deny,allow


To:

AuthType None
# AuthType Default
# Require user @SYSTEM
Order deny,allow




Restart CUPS after editing:
# systemctl restart cups

CTRL key stopped working on HP ProBook 450

Left CTRL key stopped working on HP ProBook 450 G2

My laptop runs on Linux and Windows 10 and on both systems the CTRL key did
not work properly.

BIOS was the problem.

If your CTRL key does not work, first check if you can use FN key
instead of CTRL.
For example, FN+C is the same as CTRL+C or FN+V is the same as CTRL+V.
You can try this with a line from a text.
If the FN key works as CTRL key then

turn off your laptop,
unplug it,
TAKE OUT THE BATTERY for 10-15 seconds and then put it back in and turn
the laptop on.

The CTRL key should work normally now.

How to install Popcorn Time on Linux, Watch torrent movies instantly

Linux 32 bit - Installation with CLI, Terminator
1. $ cd ~/Downloads
2. $ mkdir popcorn-time && cd popcorn-time
3. $ wget https://github.com/PopcornTime-CE/desktop/releases/download/v0.4.0-2/popcorn-time-community-v0.4.0-2-32bit.tar.xz
tar --xz -xvf popcorn-time-community-v0.4.0-2-32bit.tar.xz
4. $ ./install

Linux 64 bit - Installation with CLI, Terminator
1. $ cd ~/Downloads
2. $ mkdir popcorn-time && cd popcorn-time
3. $ wget https://github.com/PopcornTime-CE/desktop/releases/download/v0.4.0-2/popcorn-time-community-v0.4.0-2-64bit.tar.xz
tar --xz -xvf popcorn-time-community-v0.4.0-2-64bit.tar.xz
4. $ ./install

UFW on Raspbian, Raspberry Pi iptables-persistent

After upgrading Raspbian OS, and after restarting Raspberry Pi iptables is empty.
I can't connect to Raspberry PI with NFS. 

To normally start UFW after boot do the following:

$ sudo apt-get install iptables-persistent
$ sudo invoke-rc.d iptables-persistent save

How to upgrade OpenSuse 13.1 to 13.2

How to upgrade OpenSuse 13.1 to 13.2




$ su

# cat /etc/os-release

# cp -Rv /etc/zypp/repos.d /etc/zypp/repos.d.orig

# sed -i 's/13.1/13.2/g' /etc/zypp/repos.d/*

# zypper lr --uri

# zypper ref

# zypper refresh && zypper update && zypper dup

# cat /etc/os-release

configure NFS server and NFS client in OpenSuse

Example:
NFS Server IP: 192.168.1.5
NFS Client IP: 192.168.1.100
/home/user/folder : /home/your_username/your_folder


----------------------------------------
Configure NFS Server in OpenSuse 13.1:

SERVER nfs:
----------------------------------------

# zypper install nfs-kernel-server yast2-nfs-server

# systemctl enable rpcbind.service
# systemctl start rpcbind.service
# systemctl enable nfsserver.service
# systemctl start nfsserver.service

----------------------------------------

# vi /etc/exports

### share for all subnet:
/home/user/folder 192.168.1.0/24(rw,async,insecure,no_root_squash,no_subtree_check,nohide)
### share for one ip:
/home/user/folder 192.168.1.100(rw,async,insecure,no_root_squash,no_subtree_check,nohide)

----------------------------------------

# systemctl restart rpcbind.service
# systemctl restart nfsserver.service
# exportfs -a


----------------------------------------
----------------------------------------
Configure NFS Client in OpenSuse 13.1:

CLIENT nfs:
----------------------------------------

# systemctl enable rpcbind.service
# systemctl start rpcbind.service

----------------------------------------

# showmount -e 192.168.1.5

----------------------------------------

# vi /etc/fstab

192.168.1.5:/home/user_server/folder_server /client_home/client_username/client_folder   nfs     rw,async,hard,intr 0 0


----------------------------------------

Allow ports in firewall for nfs clients:
# yast > Security and Users > Firewall > Allowed Services > Add

----------------------------------------

How to create in command line qrcode with qrencode

OpenSuse 13.1

# su
# zypper refresh && zypper update && zypper dup
# zypper install qrencode

$ qrencode -o ~/Desktop/example.png "This is a example"

Distro upgrade Mint 17.1 to 17.2

$ sudo sed -i 's/rebecca/rafaela/' /etc/apt/sources.list

$ sudo sed -i 's/rebecca/rafaela/' /etc/apt/sources.list.d/official-package-repositories.list

$ sudo apt update && sudo apt upgrade && sudo apt-get -f install && apt dist-upgrade && sudo apt-get -f install

How to Huawei E173s work on OpenSuse 13.2 KDE

How to Huawei E173s-2 work on OpenSuse 13.2 KDE

------------------------------------------------------
$ lsusb
ID 12d1:1c05 Huawei Technologies Co., Ltd. E173s 3G broadband stick (modem off)

------------------------------------------------------
$ su

# mkdir /etc/usb_modeswitch.d

------------------------------------------------------
# vi /etc/usb_modeswitch.d/12d1:1c0b


#######################################################
# Huawei E173s

DefaultVendor= 0x12d1
DefaultProduct= 0x1c0b

TargetVendor= 0x12d1
TargetProduct= 0x1c0b

CheckSuccess=20

MessageEndpoint= 0x0f
MessageContent= "55534243123456780000000000000011062000000100000000000000000000"

------------------------------------------------------
# vi /lib/udev/rules.d/40-usb_modeswitch.rules

# Huawei E173s
ATTRS{idVendor}=="12d1", ATTRS{idProduct}=="1c0b", RUN+="/usr/sbin/usb_modeswitch -c /etc/usb_modeswitch.d/12d1:1c0b"

------------------------------------------------------
# vi /etc/modules


# manual override for Huawei E173s to work
usbserial vendor=0x12d1 product=0x1c0b

------------------------------------------------------
Unplug and plug the USB device type lsusb
$ lsusb
ID 12d1:1c05 Huawei Technologies Co., Ltd. E173s 3G broadband stick (modem on)

How to install Virtual Machine Manager to Mint or Ubuntu

Install Virtual Machine Manager on Mint or Ubuntu:

$ sudo apt-get install qemu-system qemu-utils libvirt-bin virt-manager python-spice-client-gtk virt-viewer

Exit fullscreen from Virtual Machine Manager on CentOS, Mint, Ubuntu

Exit fullscreen from Virtual Machine Manager on CentOS, Mint, Ubuntu

 
hit Ctrl-Alt to 'unhinge' the mouse and move the mouse to the top-middle of the screen.
A little applet drops down to allow you to leave full screen.

How to reconfigure time zone

Open a commad line, Terminal:

$ sudo dpkg-reconfigure tzdata