# Installation – web UI

This guide sets up the web UI on a Docker host, step by step. The agents on your
fail2ban hosts are covered in [agent.md](agent.md); you need both.

- Source: <https://git.retronerd.at/schiwagoa/fail2ban-webui>
- Image: `git.retronerd.at/schiwagoa/fail2ban-webui` (`amd64`, `arm64`)
- Tags: `1.0.0` (exact), `1` (latest 1.x), `latest`

## 1. Prerequisites

- Docker Engine with Compose v2 (`docker compose version`)
- Outgoing SSH (TCP 22 or your port) from the Docker host to every fail2ban host
- A DNS name and a reverse proxy with TLS for the UI (see [reverse-proxy.md](reverse-proxy.md))

Check that the subnet used in the example (`172.23.51.0/24`) is free:

```bash
docker network inspect $(docker network ls -q) --format '{{.Name}} {{range .IPAM.Config}}{{.Subnet}}{{end}}' | grep 172.23.51 \
  || echo "172.23.51.0/24 is free"
```

If it is taken, pick another `/24` and change it in step 3.

## 2. Directories

```bash
mkdir -p /opt/fail2ban-webui/config /opt/fail2ban-webui/data
cd /opt/fail2ban-webui
# the container runs as UID 10050 and needs to write to data/
chown -R 10050:10050 data
chmod 700 data
```

| Path | Content |
|---|---|
| `docker-compose.yaml` | the service |
| `.env` | settings and secrets (password hash, OIDC secret) |
| `config/hosts.yaml` | the fail2ban hosts (mounted read-only) |
| `data/` | SSH key, `known_hosts`, session secret, audit log, GeoIP database |

## 3. docker-compose.yaml

```bash
nano docker-compose.yaml
```

```yaml
# =====================================================================
# fail2ban-webui – example docker-compose.yaml
#
#   mkdir -p fail2ban-webui/{config,data} && cd fail2ban-webui
#   (copy this file, .env.example as .env and hosts.yaml.example as config/hosts.yaml)
#   chown -R 10050:10050 data
#
# The UI listens on 127.0.0.1:8080 only – put a reverse proxy with TLS in front of it.
# The network uses its own /24 subnet; change it if it collides with an existing one
# (docker network inspect $(docker network ls -q) | grep Subnet).
# =====================================================================
name: fail2ban-webui

services:
  fail2ban-webui:
    image: git.retronerd.at/schiwagoa/fail2ban-webui:latest
    # build: { context: .., dockerfile: docker/Dockerfile }   # build from the repository instead
    container_name: fail2ban-webui
    restart: unless-stopped
    env_file: .env
    environment:
      TZ: ${TZ:-Europe/Vienna}
    read_only: true
    tmpfs:
      - /tmp
    cap_drop:
      - ALL
    security_opt:
      - no-new-privileges:true
    volumes:
      - ./config:/config:ro
      - ./data:/data
    ports:
      - "127.0.0.1:8080:8080"
    extra_hosts:
      # lets the container reach an agent on the Docker host itself (address: host.docker.internal)
      - "host.docker.internal:host-gateway"
    deploy:
      resources:
        limits:
          memory: 256M
    networks:
      fail2ban-webui.dockernetwork.local:
        ipv4_address: 172.23.51.10

networks:
  fail2ban-webui.dockernetwork.local:
    name: fail2ban-webui.dockernetwork.local
    driver: bridge
    ipam:
      config:
        - subnet: 172.23.51.0/24
          gateway: 172.23.51.1
          ip_range: 172.23.51.128/25
```

If the reverse proxy runs on another machine, bind the port to the LAN address instead,
e.g. `"192.168.1.10:8080:8080"` – never to `0.0.0.0` without a firewall in front.

## 4. .env

Start with this minimal file; every option is described in
[configuration.md](configuration.md) and in [`examples/.env.example`](../examples/.env.example).

```bash
nano .env
chmod 600 .env
```

```ini
PUBLIC_URL=https://fail2ban.example.org
DEFAULT_LANG=en
TRUSTED_PROXY_HOPS=1

AUTH_MODE=local
AUTH_USER=admin
AUTH_PASSWORD_HASH='set in the next step'

SSH_USER=f2bweb
MANUAL_JAIL=manual-block
GEOIP_AUTO_DOWNLOAD=1
```

### Password hash

```bash
docker compose run --rm -it fail2ban-webui hash-password
```

Copy the printed line (`AUTH_PASSWORD_HASH='scrypt:…'`) into `.env` and replace the
placeholder. **Keep the single quotes** – the hash contains `$` signs that Docker Compose
would otherwise try to expand. For single sign-on instead see
[authentication.md](authentication.md).

## 5. SSH key

```bash
docker compose run --rm fail2ban-webui keygen
```

The command creates `data/ssh/id_ed25519` and prints the public key
(`ssh-ed25519 AAAA… fail2ban-webui`). Copy it – you need it for the agent installer.

## 6. Agents

Install the agent on every fail2ban host as described in [agent.md](agent.md). In short:

```bash
# on each fail2ban host, as root
git clone https://git.retronerd.at/schiwagoa/fail2ban-webui.git /tmp/fail2ban-webui
echo 'ssh-ed25519 AAAA… fail2ban-webui' > /tmp/webui.pub
bash /tmp/fail2ban-webui/agent/install.sh --key-file /tmp/webui.pub --from <public IP of the web UI host>
```

## 7. config/hosts.yaml

```bash
nano config/hosts.yaml
```

```yaml
hosts:
  - name: web01
    address: web01.example.org

  - name: lxc-proxy
    address: 192.168.1.20
    port: 2222

  # fail2ban on the Docker host itself
  - name: dockerhost
    address: host.docker.internal
```

`user` defaults to `SSH_USER` (`f2bweb`). Set `user: root` for hosts where the agent was
installed with `--user root`.

## 8. Host keys and connection test

```bash
docker compose run --rm -it fail2ban-webui keyscan
```

`keyscan` shows the fingerprint of every host and asks before writing
`data/ssh/known_hosts`. Compare the fingerprints with the hosts:

```bash
# on the fail2ban host
ssh-keygen -lf /etc/ssh/ssh_host_ed25519_key.pub
```

Then test every agent:

```bash
docker compose run --rm fail2ban-webui check
```

```
OK    web01                agent 1.0.0, 3 jails, 12 bans
OK    lxc-proxy            agent 1.0.0, 2 jails, 0 bans
OK    dockerhost           agent 1.0.0, 4 jails, 7 bans
```

Every host must show `OK` – see [operations.md](operations.md#troubleshooting) otherwise.

## 9. Start

```bash
docker compose up -d
docker compose ps                      # STATUS: Up … (healthy)
docker compose logs -f fail2ban-webui  # Ctrl+C to leave
```

The log shows a summary like
`fail2ban-webui 1.0.0 – hosts: web01, lxc-proxy, dockerhost – auth: local – loki: off – geoip: on`.

Local test without the proxy:

```bash
curl -s http://127.0.0.1:8080/healthz    # ok
```

## 10. Reverse proxy

Publish `http://127.0.0.1:8080` (or the LAN address from step 3) under your DNS name with
TLS – examples for Nginx Proxy Manager, Caddy, Traefik and nginx are in
[reverse-proxy.md](reverse-proxy.md). Then open `PUBLIC_URL` and sign in.

## Next steps

- [Protect the login with fail2ban](operations.md#protecting-the-login-with-fail2ban)
- [Updates and backups](operations.md)
- Optional: [Loki history and Grafana links](configuration.md#loki-and-grafana)