0x0F-load_balancer

0x0F. Load balancer

Requirements

• Allowed editors: vi, vim, emacs
• All your files will be interpreted on Ubuntu 16.04 LTS
• All your files should end with a new line
• A README.md file, at the root of the folder of the project, is mandatory
• All your Bash script files must be executable
• Your Bash script must pass Shellcheck (version 0.3.7) without any error
• The first line of all your Bash scripts should be exactly #!/usr/bin/env bash
• The second line of all your Bash scripts should be a comment explaining what is the script doing

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0. Double the number of webservers

In this first task you need to configure web-02 to be identical to web-01. Fortunately, you built a Bash script during your web server project, and they’ll now come in handy to easily configure web-02. Remember, always try to automate your work!

Since we’re placing our web servers behind a load balancer for this project, we want to add a custom Nginx response header. The goal here is to be able to track which web server is answering our HTTP requests, to understand and track the way a load balancer works. More in the coming tasks.

Requirements:

• Configure Nginx so that its HTTP response contains a custom header (on web-01 and web-02)
  • The name of the custom HTTP header must be X-Served-By
  • The value of the custom HTTP header must be the hostname of the server Nginx is running on
• Write 0-custom_http_response-header so that it configures a brand new Ubuntu machine to the requirements asked in this task
  • Ignore SC2154 for shellcheck

Example:

sylvain@ubuntu$ curl -sI 34.198.248.145 | grep X-Served-By
X-Served-By: 03-web-01
sylvain@ubuntu$ curl -sI 54.89.38.100 | grep X-Served-By
X-Served-By: 03-web-02
sylvain@ubuntu$

If your server's hostnames are not properly configured, follow this tutorial

1. Install your load balancer

Install and configure HAproxy on your lb-01 server.

Requirements:

• Configure HAproxy with version equal or greater than 1.5 so that it send traffic to web-01 and web-02
• Distribute requests using a roundrobin algorithm
• Make sure that HAproxy can be managed via an init script
• Make sure that your servers are configured with the right hostnames: [STUDENT_ID]-web-01 and [STUDENT_ID]-web-02. If not, follow this tutorial.
• For your answer file, write a Bash script that configures a new Ubuntu machine to respect above requirements

Example:

sylvain@ubuntu$ curl -Is 54.210.47.110
HTTP/1.1 200 OK
Server: nginx/1.4.6 (Ubuntu)
Date: Mon, 27 Feb 2017 06:12:17 GMT
Content-Type: text/html
Content-Length: 30
Last-Modified: Tue, 21 Feb 2017 07:21:32 GMT
Connection: keep-alive
ETag: "58abea7c-1e"
X-Served-By: 03-web-01
Accept-Ranges: bytes

sylvain@ubuntu$ curl -Is 54.210.47.110
HTTP/1.1 200 OK
Server: nginx/1.4.6 (Ubuntu)
Date: Mon, 27 Feb 2017 06:12:19 GMT
Content-Type: text/html
Content-Length: 612
Last-Modified: Tue, 04 Mar 2014 11:46:45 GMT
Connection: keep-alive
ETag: "5315bd25-264"
X-Served-By: 03-web-02
Accept-Ranges: bytes

sylvain@ubuntu$

2. Add a custom HTTP header with Puppet

Just as in task #0, we’d like you to automate the task of creating a custom HTTP header response, but with Puppet.

• The name of the custom HTTP header must be X-Served-By
• The value of the custom HTTP header must be the hostname of the server Nginx is running on
• Write 2-puppet_custom_http_response-header.pp so that it configures a brand new Ubuntu machine to the requirements asked in this task

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Author

• abdelhamed atef - abdelhamedatef2