There is a static website of Nautilus project running in Stratos Datacenter. Based on the infrastructure, they have already configured app servers and code is already deployed there. To make it work properly, they need to configure LBR server. There are number of options for that, but team has decided to go with HAproxy.
a. So install and configure HAproxy on LBR server using yum only and make sure all app servers are added to HAproxy load balancer. HAproxy must serve on default http port (Note: Please do not remove stats socket /var/lib/haproxy/stats entry from haproxy default config.).
b. You can access the website on LBR link—to do so click on the + button on top of your terminal, select option Select port to view on Host 1, and after adding port 80 click on Display Port.
Sample Answer:
#first you need to log in to all the app servers and find the Listen port ( as per the question app servers are already configured ) also need to start the httpd services too.
#login to a server
ssh <user><server>
#switch to root user
sudo su
#run below
cat /etc/httpd/conf/httpd.conf | grep Listen
*the output look likes as below ( your port might be different make a note of it we need to use in our haproxy conf file)
Listen 8084
#now start the httpd service ( make sure you started in all the app servers)
systemctl enable httpd
systemctl start httpd
systemctl status httpd
* do the above steps in all the app servers
# now login to LBR server
ssh <user>@<server>
#switch to root user
sudo su
# install the haproxy using yum
yum -y install haproxy
#copy eixting conf file before making any changes
cp /etc/haproxy/haproxy.cfg /etc/haproxy/haproxy.cfg.backup
#make sure that you do not change the below entry in the haproxy conf file (mentioned in the question)
cat /etc/haproxy/haproxy.cfg | grep haproxy/stats
#now let's add the configuration
vi /etc/haproxy/haproxy.cfg
frontend main *:80
acl url_static path_beg -i /static /images /javascript /stylesheets
acl url_static path_end -i .jpg .gif .png .css .js
use_backend static if url_static
default_backend app
backend app
balance roundrobin
server stapp01 172.16.238.10:8084 check
server stapp02 172.16.238.11:8084 check
server stapp03 172.16.238.12:8084 check
save the conf file
* make sure that your configuration as above but (port should be as per your app servers port)
#now validate the haproxy configuration file by running the below command(if there is any error it will show you otherwise its fine)
haproxy -f /etc/haproxy/haproxy.cfg
#now enable and start the haproxy service
systemctl enable haproxy
systemctl start haproxy
#let's verify, run below command from jump server ( port as per your app servers)
curl 172.16.238.10:8084
curl 172.16.238.11:8084
curl 172.16.238.12:8084
curl 172.16.238.14:80
#also verify as below
Click on the + button on top of your terminal, select the option Select port to view on Host 1, and after adding port 80 clicks on Display Port.
Note: **The Question copied it for learning purposes.** Commands are correct but based on your question the server, user name, and other details might differ, so please do check.