Table of Contents

1. Challenge

   Create a Snapshot of the Provided Container

   Take a snapshot of the container:

   lxc snapshot web01 1.0
   

2. Challenge

   Create Four Duplicate Containers

   We now want to create four web## containers based on this snapshot. We can do this manually by running lxc copy web/1.0 web## for each container, or by using a Bash script:

   vim /tmp/container-script.sh
   

   containers="web02 web03 web04 web05"
   
   for c in $containers
   do
   	lxc copy web01/1.0 $c
   	lxc start $c
   done
   

   sh /tmp/container-script.sh
   

   Confirm:

   lxc list
   

3. Challenge

   Create and Configure a Load Balancer Container

   Create a lb01 container, also based on the existing web01/1.0 snapshot:

   lxc copy web01/1.0 lb01
   lxc start lb01
   

   Open and edit the /etc/nginx/conf.d/default.conf file, and set up the load balancer. Remember that host records are set up between containers, so we can use the container names here:

   lxc file edit lb01/etc/nginx/conf.d/default.conf
   

   upstream lb {
           server web01;
           server web02;
           server web03;
           server web04;
           server web05;
   }
   
   server {
           listen 80 default_server;
           listen [::]:80 default_server;
   
           location / {
                   proxy_pass http://lb;
           }
   
   }
   

   Restart nginx:

   lxc exec lb01 -- rc-service nginx restart
   

   Test that we can access the website using curl and the IP of the load balancer:

   lxc list
   curl <lb_ip>
   

4. Challenge

   Map Ports

   Ensure that when the host's IP is accessed, it forwards to the load balancer container:

   sudo iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 80 -j DNAT --to <lb_ip>:80
   

   Navigate to the public IP of your server in your browser to ensure the load balancer works.