Changing name of salt minion CentsOS 7

We run into situation when we needed to change name of already added salt minion. Here is few simple steps that will get this done. On Salt minion Stop the Salt-Minion Service systemctl stop salt-minion Delete the current keys cd /etc/salt/pki/minion/ rm -rf minion.pub minion.pem Change the minions id in /etc/salt/minion_id vim /etc/salt/minion_id myminion.prolinuxhub.com On…

Building MariaDB Master Salve replication cluster CentOS 7

Assumptions: We have 2 Linux VMs with 5.5.56-MariaDB. IP address 192.168.0.222(cluster1.local) and 192.168.0.223(cluster2.local) We have 3 existing databases on cluster1.local – mydb1, mydb2, mydb3 Setup Master (cluster1.local) Edit my.cnf file vi /etc/my.cnf bind-address = 0.0.0.0 server_id=1 log-basename=master1 log-bin replicate-do-db = mydb1 replicate-do-db = mydb2 Restart MariaDB systemctl restart mariadb Inside MariaDB prompt GRANT REPLICATION SLAVE…

Basic salt on CentOS7 both server and client

Very quick look at how to install and use Saltstack on one vm both server and minion. Also we loot at some basic commands that are needed to manage salt deployment Installing salt Salt server can be installed in many ways Option 1 (saltstack repo) yum install https://repo.saltstack.com/yum/redhat/salt-repo-latest-2.el7.noarch.rpm yum clean expire-cache yum install salt-master yum…

Using Vagrant, VirtualBox and Ansible with CentOS 7

This would be the case when you need to test playbooks locally before using Ansible to deploy them. We assume you already have installed Vagrant, Ansible and VirtualBox. Ansible is one of many provisioners integrated with Vagrant. Lets see how it works Create Vagrant box with CentOS 7 mkdir centtest cd centtest sudo vagrant init…

Installing and using docker CentOS7

We will not cover what docker does and how it works. We assume you already familiar with basic concepts. We will look into basics of installing and operating docker on CentOS 7. We will be looking into CE )(Community Edition) Installation We will go over install using repositories yum install -y yum-utils device-mapper-persistent-data lvm2 yum-config-manager…

Installing and using LXC Containers on CentOS 7

LXC allows us to share Linux kernel to run application in something similar to chroot environment. Lets take a look at how to install and manage LXC on CentOS 7. Containers reside in /var/lib/lxc/ directory Installation yum install epel-release yum install debootstrap perl libvirt yum install lxc lxc-templates systemctl start lxc.service systemctl start libvirtd systemctl…

Zimbra Collaboration 8.8 blank screen after install

After installing Zimbra Collaboration 8.8 or upgrading from previous version you may get blank screen in some cases when accessing your management URL or Web interface. In our example we are using mysite.com smtp domain with server named mail.mysite.com Troubleshooting In the nginx log file you will see following entries cat /opt/zimbra/log/nginx.log …………client closed connection…

Bash script to test websites with curl

We will look at very basic script which will make sure multiple websites are up and running. This is very basic script that utilities power of Linux tool called curl. Curl is well know tool used to automate url related tasks and much more. The basic script will use variable called $LIST_OF_WEBSITES which will contain…

CentsOS Upgrade Nagios to 4.3.4

We had NAGIOS installed from CentOS repositories version 4.x.x. But we upgraded nrpe to version 3 which did not support old NAGIOS version that comes with repository. This is how we upgraded to veriosn 4.3.4 yum install rsync wget rsync -rav /usr/local/nagios/ /opt/nagios411backup/ wget https://assets.nagios.com/downloads/nagioscore/releases/nagios-4.3.4.tar.gz tar xf ./nagios-4.3.4.tar.gz && cd ./nagios-4.3.4 ./configure –with-command-group=nagcmd make all…

Setting up your own Monero mining pool with node-cryptonote-pool and Ubuntu 14

Feel free to use our Monero mining pool. mnrpool.tekyhost.com In this how to we will be setting up Monero mining pool with node-cryptonote-pool. We will be using Ubuntu-14.04 VPS running on VirtualBox Monero Monero first came around in April 2014. One of its main attractions is anonymity and security. Monero incorporates features into the cryptocurrency…