Puppet
If there was ever a ubiquitous tool for DevOps software deployment, it is Puppet. Even if an organization isn’t “doing DevOps,” it probably is using Puppet somewhere. Puppet is very good at getting applications deployed to pre-built infrastructure. For those just getting started with deployment automation, Puppet is a good place to start. But it is not just for beginners: According to the company, more than 3 in 4 Fortune 100 companies use Puppet for application deployment
Puppet automates the installation and configuration of applications on target servers. By writing scripts that define and install application prerequisites, setting the server variables the application requires and writing configuration scripts for applications and daemons, a team can then simply rerun the script to reinstall. A large user community has already scripted many application installations. For a large number of software applications — particularly in the open source realm — users merely need to download the relevant puppet script files and change what is written to the configuration files to reflect their project.
[Puppet Master] |192.0.0.20 ---------------- 192.0.0.30| [Puppet Agent]
Master.example.com <---------------------> Agent.example.com
Lets start to configure Puppet:-
Configure Puppet Master:-
Step:1 Update Hostname
[root@master ~]# vim /etc/hosts
192.0.0.20 master.example.com
192.0.0.30 agent.example.com
#Now try to ping by name, make sure you get the server IP address
[root@master ~]# ping master.example.com
[root@master ~]# ping agent.example.com
Step:2 Configure NTP Server
[root@master ~]# yum -y install ntp ntpdate
[root@master ~]# ntpdate 0.centos.pool.ntp.org
[root@master ~]# systemctl start ntpd
[root@master ~]# systemctl enable ntpd
Step:3 Disable SELinux
[root@master ~]# vim /etc/sysconfig/selinux
SELINUX=disabled
Step:4 Add Puppet Repository
[root@master ~]# rpm -Uvh https://yum.puppetlabs.com/puppet5/puppet5-release-el-7.noarch.rpm
[root@master ~]# reboot
Step:5 Install and Configure Puppetserver
[root@master ~]# yum -y install puppetserver
[root@master ~]# vim /etc/sysconfig/puppetserver
JAVA_ARGS="-Xms1g -Xmx1g ...."
# go to the puppet configuration directory and edit the 'puppet.conf' file.
cd /etc/puppetlabs/puppet
[root@master ~]# vim puppet.conf
# add the following configuration
[master]
dns_alt_names=master.example.com,puppet
[main]
certname = master.example.com
server = master.example.com
environment = production
runinterval = 1h
[root@master ~]# systemctl start puppetserver
[root@master ~]# systemctl puppetserver
[root@master ~]# firewall-cmd --add-port=8140/tcp --permanent
[root@master ~]# firewall-cmd --reload
Configure Puppet Agent:-
Step:1 Install and Configure Puppet Agent
[root@agent ~]# yum install -y puppet-agent
[root@agent ~]# systemctl puppetserver
[root@agent ~]# cd /etc/puppetlabs/puppet
[root@agent ~]# vim puppet.conf
# Paste the following configuration.
[main]
certname = agent.example.com
server = master.example.com
environment = production
runinterval = 1h
Step:2 # Next, we will register the puppet agent to the puppet master.
# Run the command below on the puppet agent shell.
[root@agent ~]# /opt/puppetlabs/bin/puppet resource service puppet ensure=running enable=true
The puppet agent is now running on the server, and it's attempting to register itself to the puppet master.
Step:3 Now back to the puppet master shell and run the command below.
[root@master ~]# /opt/puppetlabs/bin/puppet cert list
Step:4 Sign the certificate using the command below.
[root@master ~]# /opt/puppetlabs/bin/puppet cert sign agent.example.com
Step:5 Verify the Puppet Agent Configuration from agent machine
[root@agent ~]# /opt/puppetlabs/bin/puppet agent --test
The puppet master and agent installation and configuration have been completed.
Create Your First Manifest
we will create a simple manifest for testing.
We will create the manifest for Apache httpd web server installation.