Dotfiles/docs/md/ansipa-setup.md

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ansipa Setup Guide

ansipa = Ansible + FreeIPA: a GPO-like management plane for Linux fleets. FreeIPA provides identity, Kerberos, sudo/HBAC and host/user groups; a lightweight client-side enforcer turns group membership into enforced policy; CheckMK monitors the fleet; Keycloak adds SSO; and an nginx gateway fronts all the web UIs behind one hostname.

This guide covers a full deployment: architecture, every port, the reverse-proxy gateway, the exact snippet to expose it behind your own reverse proxy, the NAT / behind-firewall behaviour, and known distro caveats. For the policy catalogue and playbook reference see FreeIPA & Ansible.


Architecture

                    ┌─────────────────────────── docker host ───────────────────────────┐
                    │  docker network ipa-net (172.30.0.0/24)                            │
   your reverse     │                                                                    │
   proxy (TLS)      │   ┌── ansipa-nginx (gateway) ──┐                                   │
        │           │   │  /      portal start page  │                                   │
   https://ansipa ──┼──►│  /ipa/  ─► freeipa  :443 ───┼──► 172.30.0.10  FreeIPA          │
   .example.com     │   │  /cmk/  ─► checkmk  :5000 ──┼──► 172.30.0.12  CheckMK          │
   (:443)           │   │  /auth/ ─► keycloak :8080 ──┼──► keycloak     Keycloak         │
                    │   └────────────────────────────┘         │                        │
                    │        :8088 (http)                       └─ postgres (KC backend) │
                    └────────────────────────────────────────────────────────────────────┘
                                     ▲                                   ▲
              client-initiated only  │ (enroll, kinit, policy pull,      │
              — works across NAT     │  CheckMK push :8000)              │
                    ┌────────────────┴───────────┐        ┌──────────────┴─────────────┐
                    │ enrolled client (Arch)     │        │ enrolled client (Fedora…)  │
                    │ ansipa-enforce-policies     │        │ SSSD + Kerberos + enforcer │
                    │ .timer (every 30 min)       │        │                            │
                    └─────────────────────────────┘        └────────────────────────────┘

The design is pull-based: the server never initiates connections to clients. Every enrolled host runs ansipa-enforce-policies.sh on a 30-minute timer, does kinit -k host/$FQDN, reads its own group memberships from FreeIPA, and applies the matching policies locally. This is what makes the whole system work when clients are behind NAT (see Clients behind NAT).


Bringing up the server stack

cd setup/modules/FreeipaAnsible/image
cp .env.example .env && $EDITOR .env      # set domain, realm, passwords, ports

# cgroup v2 hosts (WSL2, modern Fedora/Ubuntu/Arch): use the run.sh wrapper —
# the FreeIPA container needs --cgroupns host, which compose cannot express.
./run.sh all        # freeipa + postgres + keycloak + checkmk + nginx gateway
#   ./run.sh        # freeipa only
#   ./run.sh down   # stop everything

# plain cgroup v1 hosts can use compose directly:
docker compose up -d

docker compose logs -f freeipa      # watch first-boot (~10 min)
./keycloak-configure.sh             # wire Keycloak → FreeIPA LDAP (once healthy)

Ports

Server (published on the docker host)

Port Proto Service Notes
389 TCP LDAP FreeIPA directory
636 TCP LDAPS FreeIPA directory (TLS)
88 TCP+UDP Kerberos KDC
464 TCP+UDP kpasswd password changes
443 TCP HTTPS FreeIPA web UI (also proxied at /ipa/)
445 TCP SMB Samba shares (scans, LUKS keys, policy store)
137 UDP NetBIOS name Samba
138 UDP NetBIOS datagram Samba
139 TCP NetBIOS session Samba
8090 TCP CheckMK web UI container :5000 → host 8090 (also proxied at /cmk/)
8000 TCP CheckMK agent receiver push-mode target for NAT clients
6557 TCP CheckMK livestatus optional, external tooling
8080 TCP Keycloak HTTP dev mode (also proxied at /auth/)
8443 TCP Keycloak HTTPS needs a cert for the start command
8088 TCP nginx gateway single entry for the portal + all UIs (ANSIPA_HTTP_PORT)

Client (only needed for CheckMK pull mode)

Port Proto Service Notes
6556 TCP check_mk agent socket server → client; unreachable across NAT, use push mode instead
22 TCP sshd if the client is in dev_daemon-enable-sshd and you manage over SSH

The nginx gateway (portal + reverse proxy)

The ansipa-nginx service fronts all three web UIs on one hostname/port and serves a portal landing page. Each backend is proxied at the path it already uses natively, so there is no path rewriting to fight:

Path Backend Notes
/ portal start page static, links to the three UIs
/ipa/ FreeIPA :443 Host + Referer pinned to the IPA hostname (IPA anti-CSRF)
/cmk/ CheckMK :5000 CheckMK already serves under /cmk
/auth/ Keycloak :8080 Keycloak runs with KC_HTTP_RELATIVE_PATH=/auth

The gateway speaks plain HTTP on ANSIPA_HTTP_PORT (default 8088) and trusts X-Forwarded-*, so it is designed to sit behind your own TLS-terminating reverse proxy.

Exposing ansipa behind your main reverse proxy

Point one hostname at the gateway. TLS is terminated by your proxy; ansipa receives plain HTTP and reads X-Forwarded-Proto to build correct URLs.

nginx (add to your main reverse proxy):

server {
    listen 443 ssl;
    server_name ansipa.example.com;
    # ssl_certificate / ssl_certificate_key ...

    location / {
        proxy_pass http://DOCKER_HOST_IP:8088;
        proxy_set_header Host              $host;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_set_header X-Forwarded-For   $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Host  $host;
    }
}

Caddy (one line):

ansipa.example.com {
    reverse_proxy DOCKER_HOST_IP:8088
}

Traefik (docker labels on the nginx service): route the host rule to the ansipa-nginx service on port 80.

Both CheckMK and Keycloak generate some absolute URLs from their own configured hostname rather than the forwarded one. For a clean deployment behind a public name, set:

  • Keycloak: KC_HOSTNAME=https://ansipa.example.com/auth in .env.
  • CheckMK: set the site's URL prefix / base URL to your public https://ansipa.example.com/cmk/ (OMD → Global settings → User interface → Base URL), so login redirects use https and the public host.

Without these the UIs are still reachable through the proxy; only some redirects fall back to the container-internal scheme/host.


Clients behind NAT

The controller can live on the public internet while clients sit behind NAT — the architecture is client-initiated end to end:

Function Direction Works behind NAT?
Enrollment (ipa-client-install) client → server
Policy enforcement (30-min timer) client → server (kinit + ipa reads)
Policy store sync client → server SMB
CheckMK pull (:6556) server → client — blocked by NAT
CheckMK push (cmk-agent-ctl:8000) client → server

So policies and identity Just Work across NAT. For monitoring, NAT clients must use push mode: the server records a push request for each host in dev_mon_base (ansipa-checkmk-setup.sh writes /cmk-creds/push-mode-<host>.req, the CheckMK container consumes it and flips the host to cmk_agent_connection: push-agent), and the client registers with cmk-agent-ctl register --server <host>:8000. Advertise a client-routable CheckMK URL so agents can reach the server — set CMK_ADVERTISED_URL in .env (e.g. http://mon.example.com:8090); it is stored in the dev_mon_base group description and must NOT be the container-internal 172.30.0.12.

Note: push mode needs the full CheckMK agents cmk-agent-ctl binary. RPM/DEB distros ship it in the agent package; on Arch the portable check_mk_agent fallback lacks it, so an Arch NAT client enrolls and gets policies but needs cmk-agent-ctl installed manually for push monitoring.


Deploying as a Proxmox LXC container

To run the whole stack as a single Proxmox container, use the generator:

bash setup/tools/ansipa-proxmox-lxc.sh [OUT_DIR]   # default ~/ansipa-lxc-out

It prompts for domain/realm/VMID/resources, generates all secrets, and writes:

File Purpose
pct-create-<vmid>.sh pct create command — run on the Proxmox host
ansipa-<vmid>.conf LXC options to append to /etc/pve/lxc/<vmid>.conf
ansipa-provision.sh first-boot provisioner (installs Docker, brings the stack up)
.env filled-in stack environment (generated passwords — mode 600)
DEPLOY-<vmid>.md step-by-step guide

The container is privileged with nesting=1,keyctl=1,fuse=1 — required for FreeIPA's systemd + Kerberos keyrings and Docker's overlay2. It runs the same tested docker-compose stack inside the CT ("Docker-in-LXC"), so it is the full ansipa deployment in one Proxmox container. Size it ≥6 GB RAM.

setup/tools/freeipa-image.sh has a separate proxmox-lxc target that exports a FreeIPA-only CT rootfs (no CheckMK/Keycloak/nginx) — use that if you want just the identity server; use ansipa-proxmox-lxc.sh for the full stack.


Client enrollment

# on the client, as root:
sudo ./freeipa-enroll.sh --domain ansipa.example.com --realm ANSIPA.EXAMPLE.COM \
     --server ipa.ansipa.example.com --hostname client01.ansipa.example.com
# (IPA_PASSWORD env var or --password; --no-dns-update if IPA does not run DNS)

Supported distros: Arch, Fedora, RHEL/Rocky/AlmaLinux, Debian/Ubuntu. The script picks the right package manager and package names automatically.

Arch caveat — autofs / freeipa-client from the AUR

On Arch, ipa-client-install comes from the AUR freeipa-client package, which pulls the entire FreeIPA suite plus autofs from source — a long build (tens of minutes on a small VM). ansipa bundles its own autofs-pkgbuild/ that builds autofs from upstream git, because the stock AUR autofs currently fails (its pinned autofs-5.1.9.tar.xz was pruned from kernel.org). freeipa-enroll.sh builds and installs it automatically before the AUR freeipa-client step, so no manual intervention is needed — just expect the first enrollment to take a while.


Verifying a deployment

# server
docker compose ps                         # all healthy
curl -fsS http://DOCKER_HOST_IP:8088/ | grep ansipa   # portal
# client (after enrollment + one enforcer run)
id admin                                  # SSSD resolves IPA users
kinit admin && klist                      # Kerberos works
sudo /usr/local/bin/ansipa-enforce-policies.sh   # apply policies now
sudo systemctl list-timers ansipa-enforce-policies.timer