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.

  1. 01reconversion (server_version_num), data_directory, config_file and hba_file of the running cluster
  2. 02reconcurrent pg_hba rules (trust? md5? 0.0.0.0/0?)
  3. 03reconcurrent listen_addresses, ssl and password_encryption
  4. 04reconroles whose password is still md5-hashed (blocks the move to scram)
  5. 05reconactive remote connections not to cut
  6. 06actBack up the configverify
  7. 07actForce scram-sha-256 for new passwordsverify
  8. 08actRestrict pg_hbadestructiveverify
  9. 09actEnable SSLverify
  10. 10actReloadverify

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.

  1. 01Back up the configVerified byls <hba_file>.bak.* | tail -1
  2. 02Force scram-sha-256 for new passwordsVerified bygrep password_encryption <data_directory>/postgresql.auto.conf
  3. 03Restrict pg_hbaVerified bysudo -u postgres psql -tAc "select count(*) from pg_hba_file_rules where error is not null or (type <> 'local' and auth_method = 'trust')"
  4. 04Enable SSLVerified byls <data_directory>/server.crt /etc/ssl/certs/ssl-cert-snakeoil.pem 2>/dev/null | head -1
  5. 05ReloadVerified bysudo -u postgres psql -tAc 'show ssl'

SEC.03

Guardrails

Non-negotiable instructions the run must respect, whatever it finds on the server.

Do NOT cut off the running application’s access — check active connections first. Always back up pg_hba.conf and postgresql.conf before changing them. Do not change listen_addresses (report only). If pg_hba_file_rules shows an error, restore the .bak and do not reload.

SEC.04

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.

recipe — fail2ban_setup150+ in catalogue
security4 steps · low risk · idempotentrun
reconsshd present? ufw active? existing jails?✓
actinstall fail2ban · write default jails✓
actenable service · restart sshd (safe)✓
verifytest ban 60s · jails active · sshd alive✓

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.05

Deploy on Servor button

Maintain Postgres Hardening 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.

Deploy on ServorDark background
Deploy on ServorLight background
[![Deploy on Servor](https://servor.app/badges/deploy-on-servor.svg)](https://servor.app/deploy/harden-postgres)

SEC.06

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.