Main configuration file (nginx.conf) - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the nginx.conf file?

The nginx.conf file is the main configuration file for the NGINX web server. It controls how NGINX behaves, including server settings, modules, and how requests are handled.

beginner

Name the main blocks inside nginx.conf.

The main blocks are: events (handles connection processing), http (handles web traffic), and server (defines virtual hosts).

beginner

What does the worker_processes directive control?

It sets how many worker processes NGINX will run. More workers can handle more connections, like having more cashiers in a store to serve customers faster.

beginner

Explain the role of the server block in nginx.conf.

The server block defines a virtual server. It tells NGINX how to respond to requests for a specific domain or IP, including ports, root folders, and rules.

beginner

How do you reload NGINX after changing nginx.conf without downtime?

Use the command nginx -s reload. This tells NGINX to apply changes smoothly without stopping the server, like changing a light bulb without turning off the room.

Which block in nginx.conf handles web traffic settings?

A http

B events

C server

D location

The http block manages web traffic settings like headers, compression, and proxy settings.

What does the worker_connections directive specify?

A Number of worker processes

B Number of connections each worker can handle

C Port number for the server

D Timeout for client connections

worker_connections sets how many connections each worker process can handle at the same time.

Where do you define the root folder for your website in nginx.conf?

A Inside the <code>http</code> block only

B Inside the <code>events</code> block

C In the <code>worker_processes</code> directive

D Inside the <code>server</code> block

The root folder is set inside the server block, telling NGINX where to find website files.

What command reloads NGINX configuration without downtime?

A nginx -s reload

B nginx -s stop

C nginx -s start

D nginx -s restart

nginx -s reload reloads the config smoothly without stopping the server.

Which directive controls how many worker processes NGINX runs?

A server_name

B worker_connections

C worker_processes

D listen

worker_processes sets the number of worker processes.

Describe the main sections of the nginx.conf file and their roles.

Think of how NGINX organizes its tasks like a team with different roles.

Explain how to safely apply changes made to nginx.conf without stopping the web server.

Imagine changing a part of a machine while it keeps running.

Practice

1. What is the primary purpose of the nginx.conf file in NGINX?

easy

A. To manage user accounts and permissions

B. To store website content like HTML and images

C. To log errors and access information

D. To configure how NGINX handles web requests and server behavior

Solution

1. Step 1: Understand the role of nginx.conf

   The nginx.conf file is the main configuration file that controls how NGINX behaves and processes requests.

2. Step 2: Differentiate from other files

   Files like logs store errors or access info, and website content files hold HTML/images, but nginx.conf sets server rules.

3. Final Answer:

   To configure how NGINX handles web requests and server behavior -> Option D

4. Quick Check:

   Main config file = server behavior [OK]

Hint: Remember: nginx.conf sets server rules, not content or logs [OK]

Common Mistakes:

• Confusing nginx.conf with website files
• Thinking nginx.conf stores logs
• Assuming nginx.conf manages users

2. Which of the following is the correct syntax to include another configuration file inside nginx.conf?

easy

A. include /etc/nginx/conf.d/*.conf;

B. import /etc/nginx/conf.d/*.conf;

C. load /etc/nginx/conf.d/*.conf;

D. attach /etc/nginx/conf.d/*.conf;

Solution

1. Step 1: Recall the directive for including files

   NGINX uses the include directive to add other config files inside nginx.conf.

2. Step 2: Check syntax correctness

   The correct syntax is include path; with a semicolon. Other words like import, load, attach are invalid in NGINX.

3. Final Answer:

   include /etc/nginx/conf.d/*.conf; -> Option A

4. Quick Check:

   Include directive = include [OK]

Hint: Use 'include' to add files, ends with semicolon [OK]

Common Mistakes:

• Using 'import' or 'load' instead of 'include'
• Forgetting the semicolon at the end
• Wrong directive names

3. Given this snippet from nginx.conf:

http {
    server {
        listen 80;
        server_name example.com;
        location / {
            root /var/www/html;
        }
    }
}

What will happen when a user visits http://example.com/?

medium

A. NGINX serves files from /var/www/html directory

B. NGINX returns a 404 error because root is missing a semicolon

C. NGINX redirects to HTTPS automatically

D. NGINX blocks the request due to missing listen directive

Solution

1. Step 1: Analyze the server block

   The server listens on port 80 and responds to requests for example.com. The location / block sets the root directory to /var/www/html.

2. Step 2: Understand the effect of root directive

   When a user visits the site root, NGINX serves files from /var/www/html. The semicolon is present, so syntax is correct.

3. Final Answer:

   NGINX serves files from /var/www/html directory -> Option A

4. Quick Check:

   Root directive sets file location = serve files [OK]

Hint: Root directive points to file folder served [OK]

Common Mistakes:

• Assuming missing semicolon causes error (it's present)
• Thinking HTTPS redirect happens automatically
• Ignoring listen directive presence

4. Identify the error in this nginx.conf snippet:

http {
    server {
        listen 80
        server_name mysite.com;
        location / {
            root /usr/share/nginx/html;
        }
    }
}

medium

A. root directive path is incorrect

B. server_name directive is invalid

C. Missing semicolon after listen 80

D. location block cannot be inside server block

Solution

1. Step 1: Check syntax of directives

   Each directive must end with a semicolon. The line listen 80 is missing a semicolon.

2. Step 2: Validate other directives

   The server_name and root directives are correctly written. The location block is correctly nested inside server.

3. Final Answer:

   Missing semicolon after listen 80 -> Option C

4. Quick Check:

   Every directive ends with semicolon [OK]

Hint: Check every directive ends with semicolon [OK]

Common Mistakes:

• Ignoring missing semicolon errors
• Thinking server_name syntax is wrong
• Misunderstanding block nesting rules

5. You want to serve two websites on the same NGINX server using nginx.conf. Which configuration correctly sets up two server blocks for site1.com and site2.com on port 80?

hard

A. http {
server {
listen 80;
server_name site1.com site2.com;
root /var/www/site1;
}
}

B. http {
server {
listen 80;
server_name site1.com;
root /var/www/site1;
}
server {
listen 80;
server_name site2.com;
root /var/www/site2;
}
}

C. http {
server {
listen 80;
server_name site1.com;
root /var/www/site1;
}
location /site2 {
root /var/www/site2;
}
}

D. http {
server {
listen 80;
server_name site1.com;
root /var/www/site1;
}
server {
listen 8080;
server_name site2.com;
root /var/www/site2;
}
}

Solution

1. Step 1: Understand multiple server blocks

   To serve two sites on the same port, create two separate server blocks each with its own server_name and root.

2. Step 2: Evaluate each option

   http {
       server {
           listen 80;
           server_name site1.com;
           root /var/www/site1;
       }
       server {
           listen 80;
           server_name site2.com;
           root /var/www/site2;
       }
   }

   correctly defines two server blocks both listening on port 80 with different server_name and root.

   http {
       server {
           listen 80;
           server_name site1.com site2.com;
           root /var/www/site1;
       }
   }

   combines names in one block, serving only one root.

   http {
       server {
           listen 80;
           server_name site1.com;
           root /var/www/site1;
       }
       location /site2 {
           root /var/www/site2;
       }
   }

   uses location incorrectly for separate site.

   http {
       server {
           listen 80;
           server_name site1.com;
           root /var/www/site1;
       }
       server {
           listen 8080;
           server_name site2.com;
           root /var/www/site2;
       }
   }

   uses different ports, not both on 80.

3. Final Answer:

   Two server blocks on port 80 with separate server_name and root -> Option B

4. Quick Check:

   Separate server blocks = separate sites [OK]

Hint: Use separate server blocks with unique server_name for each site [OK]

Common Mistakes:

• Combining multiple domains in one server block with one root
• Using location blocks instead of server blocks for separate sites
• Assigning different ports when same port is required