Let's Encrypt with Certbot in Nginx - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the command to install Certbot on Ubuntu.

Nginx

sudo apt-get install [1]

Drag options to blanks, or click blank then click option'

Acertbot

Bnginx

Cdocker

Dmysql

Attempts:

3 left

💡 Hint

Common Mistakes

Installing nginx instead of certbot.

Trying to install unrelated packages like docker or mysql.

The package certbot is used to obtain Let's Encrypt certificates.

2fill in blank

medium

Complete the command to obtain a certificate for example.com using Certbot with nginx plugin.

Nginx

sudo certbot --[1] nginx -d example.com

Drag options to blanks, or click blank then click option'

Arenew

Bnginx

Crun

Dcertonly

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'renew' when you want to get a new certificate.

Using 'certonly' which does not install the certificate automatically.

The run command tells Certbot to obtain and install the certificate automatically using the nginx plugin.

3fill in blank

hard

Fix the error in the nginx server block to enable SSL by completing the directive.

Nginx

listen 443 ssl [1];

Drag options to blanks, or click blank then click option'

Ahttp2

Bproxy_pass

Cserver_name

Droot

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'proxy_pass' which is for reverse proxy settings.

Using 'server_name' or 'root' which are unrelated here.

The http2 directive enables HTTP/2 protocol on the SSL port 443.

4fill in blank

hard

Fill both blanks to configure Certbot to automatically renew certificates and reload nginx after renewal.

Nginx

0 3 * * * certbot renew --[1]-hook "systemctl [2] nginx"

Drag options to blanks, or click blank then click option'

Apost

Brestart

Creload

Dpre

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'pre-hook' which runs before renewal.

Using 'restart' which causes downtime.

The post-hook runs after renewal, and reload reloads nginx to apply new certificates without downtime.

5fill in blank

hard

Fill all three blanks to create a secure nginx server block snippet for SSL with Let's Encrypt certificates.

Nginx

server {
    listen 443 ssl [1];
    server_name [2];
    ssl_certificate /etc/letsencrypt/live/[3]/fullchain.pem;
}

Drag options to blanks, or click blank then click option'

Ahttp2

Bexample.com

Cmydomain.com

Ddefault

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'default' as server_name which is not a domain.

Mismatching domain names in server_name and certificate path.

Enable http2 on port 443, set server_name to your domain (here 'mydomain.com'), and use the same domain folder for the certificate path.

Practice

1. What is the main purpose of using Certbot with nginx when working with Let's Encrypt?

easy

A. To create backups of nginx configuration files

B. To configure nginx to serve static files faster

C. To monitor server performance and uptime

D. To automatically obtain and install SSL certificates for secure HTTPS connections

Solution

1. Step 1: Understand Certbot's role

   Certbot is a tool designed to automate the process of obtaining SSL certificates from Let's Encrypt.

2. Step 2: Connect Certbot with nginx

   Certbot can automatically configure nginx to use these certificates, enabling HTTPS.

3. Final Answer:

   To automatically obtain and install SSL certificates for secure HTTPS connections -> Option D

4. Quick Check:

   Certbot = SSL automation [OK]

Hint: Certbot automates SSL setup for nginx [OK]

Common Mistakes:

• Thinking Certbot monitors server performance
• Confusing Certbot with backup tools
• Believing Certbot speeds up static file delivery

2. Which of the following is the correct command to obtain and install a certificate for nginx using Certbot?

easy

A. certbot renew --nginx

B. certbot --nginx -d example.com

C. certbot --apache -d example.com

D. certbot install --nginx example.com

Solution

1. Step 1: Identify the command to obtain and install

   The command to get and install a certificate for nginx is 'certbot --nginx -d domain'.

2. Step 2: Check options correctness

   certbot --nginx -d example.com uses '--nginx' and '-d example.com' correctly. certbot --apache -d example.com is for Apache, A is for renewal, D is invalid syntax.

3. Final Answer:

   certbot --nginx -d example.com -> Option B

4. Quick Check:

   Certbot obtain + nginx = certbot --nginx -d [OK]

Hint: Use '--nginx' flag with '-d' domain to get cert [OK]

Common Mistakes:

• Using '--apache' flag for nginx
• Confusing 'renew' with 'obtain' commands
• Using invalid 'install' subcommand

3. After running certbot --nginx -d example.com successfully, what will be the expected change in the nginx configuration?

medium

A. nginx config will include SSL directives and listen on port 443

B. nginx will stop serving HTTP requests

C. nginx config will remove all server blocks

D. nginx will only serve HTTP on port 80

Solution

1. Step 1: Understand Certbot's nginx plugin effect

   Certbot modifies nginx config to add SSL settings and enable HTTPS on port 443.

2. Step 2: Analyze expected config changes

   It does not remove server blocks or disable HTTP; it adds SSL directives alongside HTTP.

3. Final Answer:

   nginx config will include SSL directives and listen on port 443 -> Option A

4. Quick Check:

   Certbot adds SSL and port 443 config [OK]

Hint: Certbot adds SSL and port 443 to nginx config [OK]

Common Mistakes:

• Thinking HTTP is disabled after certbot run
• Believing server blocks are deleted
• Assuming nginx only listens on port 80

4. You ran certbot --nginx -d example.com but got an error: Failed authorization procedure. What is the most likely cause?

medium

A. Certbot version is too new

B. nginx is not installed on the server

C. Port 80 is blocked or not accessible from the internet

D. The domain name is misspelled in the command

Solution

1. Step 1: Understand the error meaning

   'Failed authorization procedure' means Let's Encrypt could not verify domain ownership.

2. Step 2: Identify common cause

   Let's Encrypt uses HTTP challenge on port 80; if blocked, verification fails.

3. Final Answer:

   Port 80 is blocked or not accessible from the internet -> Option C

4. Quick Check:

   Port 80 open = authorization success [OK]

Hint: Check port 80 accessibility for HTTP challenge [OK]

Common Mistakes:

• Assuming nginx absence causes authorization error
• Ignoring domain spelling mistakes
• Blaming Certbot version without checking network

5. You want to automate renewal of your Let's Encrypt certificates on nginx using Certbot. Which approach is best?

hard

A. Set up a cron job to run certbot renew --quiet regularly

B. Manually run certbot --nginx -d example.com every month

C. Restart nginx daily to trigger automatic renewal

D. Delete old certificates and request new ones weekly

Solution

1. Step 1: Understand Certbot renewal process

   Certbot can renew certificates automatically using the 'renew' command.

2. Step 2: Automate renewal with cron

   Setting a cron job to run 'certbot renew --quiet' regularly ensures certificates renew before expiry without manual work.

3. Final Answer:

   Set up a cron job to run certbot renew --quiet regularly -> Option A

4. Quick Check:

   Automate renewal with cron + certbot renew [OK]

Hint: Use cron with 'certbot renew --quiet' for auto-renewal [OK]

Common Mistakes:

• Manually renewing certificates often
• Restarting nginx does not renew certs
• Deleting certs causes downtime and errors