SEC.01
The playbook
The run starts read-only: the recon probes decide what happens next. The steps that follow are adapted to the distribution and state found — a real machine is rarely clean.
- 01recondistro and version: apt (Debian/Ubuntu) or dnf (RHEL/Fedora/Rocky/Alma)?
- 02reconMosquitto already present? which version?
- 03reconservice active?
- 04reconexisting config: listeners, allow_anonymous, password_file, include_dir conf.d?
- 05reconis port 1883 already taken (by which process)?
- 06reconis a firewall (ufw or firewalld) active?
- 07actInstall Mosquitto (if missing)verify
- 08actCreate the ${mqtt_user} userverify
- 09actListen with authenticationverify
- 10actEnable and restartverify
- 11actOpen 1883 (only if public exposure and an active firewall)verify
- 12actPublish with authenticationverify
SEC.02
What it verifies
Each step ships its own check. The run only moves on when the check passes, so what the recipe reports as done is what is actually on the server.
- 01verifyInstall Mosquitto (if missing)Verified by
command -v mosquitto mosquitto_passwd - 02verifyCreate the ${mqtt_user} userVerified by
grep -c "^${mqtt_user}:" /etc/mosquitto/passwd - 03verifyListen with authenticationVerified by
grep -rh "allow_anonymous false" /etc/mosquitto/ | head -1 - 04verifyEnable and restartVerified by
systemctl is-active mosquitto - 05verifyOpen 1883 (only if public exposure and an active firewall)Verified by
ufw status 2>/dev/null | grep -c "^1883/tcp"; firewall-cmd --list-ports 2>/dev/null; true - 06verifyPublish with authenticationVerified by
mosquitto_pub -h 127.0.0.1 -t servor/test -m ok -u ${mqtt_user} -P "$(cat /root/.servor/mosquitto-${mqtt_user}.pass)" && echo ok
SEC.03
Guardrails
Non-negotiable instructions the run must respect, whatever it finds on the server.
Never allow anonymous access (allow_anonymous false). Do not rewrite /etc/mosquitto/passwd with -c if it exists. The generated password stays in /root/.servor/ and is never shown in a report. For public exposure, recommend TLS (8883) for remote clients.
SEC.04
Variables
What you choose before launching — the recipe fills in the rest.
| Name | Meaning |
|---|---|
| ${mqtt_user} | MQTT user |
| ${exposure} | Exposure |
SEC.05
How a recipe runs in Servor
Servor is zero-knowledge: the platform cannot execute anything on its own. When you launch this recipe, a run reads the reconnaissance, plans the steps and asks for your approval. Each approved command is signed by your browser — with a key the server never sees — then relayed verbatim to the agent, which verifies the signature locally before executing.
search by intent — type “firewall”, get ufw
- 01Read-only reconnaissance before any change
- 02Every command signed by your browser, approved by you
- 03Each step verified before the run moves on, every run kept in the history
SEC.06
Deploy on Servor button
Maintain Mosquitto (MQTT) or a project that needs it? Put this button in your README or on your site: one click and your users install it on their own server.
SEC.07
More cache & queues recipes
Verified recipe
Run this recipe on your server
Connect a server, launch the recipe, and approve each step as Servor executes and verifies it. Free plan, no card required.