Back to commands

Hosting Operations

Read-only

List Certbot Certificates

You need to see Certbot-managed certificates and included domains.

Command

certbot certificates

Before you run this

System impact: Read-only. Low when scoped to the shown target.

When not to use it: Do not assume public DNS is correct just because a certificate exists locally.

Expected output

Certificate names, domains, and expiry details.

System impact

Read-only. Nothing changes. The command prints certificate inventory.

Recovery / rollback: no state is changed.

When to use it

Use this before renewing, expanding, or debugging Let's Encrypt certificates.

When not to use it

Do not assume public DNS is correct just because a certificate exists locally.

Watch this command run

Command transcript

This sanitized transcript shows the commands and output shape without exposing host details.

demo@lab:~$

$ certbot certificates

Certificate Name: example.com
    Domains: example.com example.com
    Expiry Date: 2026-09-23 10:00:00+00:00 (VALID: 90 days)

$ curl -sI https://example.com

HTTP/2 200
server: lab-nginx
x-content-type-options: nosniff

$ dig +short example.com A

203.0.113.10
View commands shown

These are the commands shown in the sanitized transcript.

Commands shown

  1. certbot certificates
  2. curl -sI https://example.com
  3. dig +short example.com A

next steps

Related commands

Hosting Operations Read-only

Find Top 404 URLs

The missing file was not random. The access log had a pattern.

awk '$9==404 {print $7}' /var/log/nginx/access.log | sort | uniq -c | sort -nr | head
Hosting Operations Read-only

Show Enabled Nginx Sites

The config existed, but it was not enabled.

ls -l /etc/nginx/sites-enabled/
Hosting Operations Read-only

See Top Referrers

LinkedIn traffic was not a guess. The referrer field showed it.

awk -F'"' '{print $4}' /var/log/nginx/access.log | sort | uniq -c | sort -nr | head
Hosting Operations Can be slow

List Nginx Listen Directives

The site was configured, but the port was not.

grep -RInE '^[[:space:]]*listen[[:space:]]' fixtures/nginx/conf.d fixtures/nginx/sites-enabled
Hosting Operations Can be slow

Show Nginx Include Lines

The config was valid; it just was not included.

grep -RInE '^[[:space:]]*include[[:space:]]' fixtures/nginx/nginx.conf fixtures/nginx/conf.d fixtures/nginx/sites-enabled
Study mapping

Use this as independent command practice: read the notes, predict the output, then compare it with the example before using a real shell.

  • lfcs:operations-deployment
  • lfcs:services-logs
  • risk:read-only

Useful for

  • LPIC-1 style command-line practice
  • LFCS style performance tasks
  • Linux+ style troubleshooting review

Independent study support only. No affiliation, endorsement, exam dumps, or real exam questions.