Web Server Rescue
Read-onlySmoke Check an HTTP Status
You need a quick status-code check after a deployment.
Command
curl -fsS -o /dev/null -w '%{http_code} %{time_total}s\n' https://example.com/healthBefore you run this
System impact: Read-only. Low when scoped to the shown target.
When not to use it: Do not use it for endpoints where a GET request has side effects.
Expected output
A status code and total request time, such as 200 0.183s.
System impact
Read-only. Nothing changes locally. The command sends one HTTP GET request.
Recovery / rollback: no state is changed.
When to use it
Use after deployments, restarts, or DNS changes.
When not to use it
Do not use it for endpoints where a GET request has side effects.
Explanation-only example
Illustrated output, not a live lab run
This example is intentionally illustrative. It shows the command shape without killing real processes or changing your machine.
$ printf 'Checking endpoint status\n'
Checking endpoint status$ curl -fsS -o /dev/null -w '%{http_code} %{time_total}s\n' https://example.com/health
200 0.042000sView commands shown
These are the commands shown in the sanitized transcript.
Commands shown
printf 'Checking endpoint status\n'curl -fsS -o /dev/null -w '%{http_code} %{time_total}s\n' https://example.com/health
next steps
Related commands
Your Site Is Not Down. DNS Might Be Lying.
The browser said the site was gone. The server was answering fine.
curl --resolve example.com:443:203.0.113.10 https://example.com/
Check the Certificate Served for SNI
The IP was right. The SNI name selected the wrong certificate.
openssl s_client -connect 203.0.113.10:443 -servername wrong.edge.test </dev/null 2>/dev/null | openssl x509 -noout -subject -ext subjectAltName
Show TLS Certificate Dates
The outage was not the web server. The edge certificate had expired.
openssl s_client -connect edge.test:443 -servername edge.test </dev/null 2>/dev/null | openssl x509 -noout -dates
Show TLS Certificate Names
The cert was valid, but not for this hostname.
openssl s_client -connect edge.test:443 -servername edge.test </dev/null 2>/dev/null | openssl x509 -noout -subject -ext subjectAltName
Show TLS Protocol and Cipher
The certificate was fine. The TLS negotiation told the rest of the story.
openssl s_client -connect edge.test:443 -servername edge.test </dev/null 2>/dev/null | awk '/Protocol|Cipher|Verify return code/ {print}'
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.
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.