Docker - Grafana, InfluxDB and Collectd with FritzBox plugin

A fully self-contained monitoring stack for AVM FritzBox routers. Collects router metrics via the fritzcollectd plugin, stores them in InfluxDB, and displays them in a pre-provisioned Grafana dashboard — no manual Grafana configuration needed.

What's included

• compose.yml — Docker Compose stack (Grafana, InfluxDB, collectd-fritzbox)
• collectd-fritzbox/ — Dockerfile and config for the collectd container
• influxdb.conf / types.db — InfluxDB configuration and collectd type definitions
• grafana/provisioning/ — Auto-provisioned datasource and dashboard (no manual import needed)
• .env.example — Template for all required environment variables

Requirements

• Docker with Docker Compose
• A host machine IP reachable from the collectd container (used for INFLUXDB_HOST)
• A FritzBox router with TR-064 / UPnP enabled and a dedicated user

Getting started

1. Clone the repository

2. Copy .env.example to .env and fill in your values:

   cp .env.example .env
   

3. Key variables to set in .env:

   Variable	Description
   INFLUXDB_HOST	Host machine IP (not localhost — collectd uses host networking)
   INFLUXDB_ADMIN_USER / INFLUXDB_ADMIN_PASSWORD	InfluxDB credentials
   FRITZBOX_IP	FritzBox LAN IP (usually 192.168.178.1)
   FRITZBOX_USER / FRITZBOX_PASSWORD	FritzBox user with TR-064 access
   GRAFANA_ADMIN_USER / GRAFANA_ADMIN_PASSWORD	Grafana login (default: admin/admin)

4. Start the stack (builds the collectd-fritzbox image locally):

   docker compose up -d --build
   

5. Open Grafana at http://<your-host>:3000 and log in with your configured credentials.

   • The InfluxDB datasource is auto-provisioned on first start
   • The FritzBox dashboard is auto-provisioned on first start — no import needed

Data persistence

Grafana and InfluxDB data are stored in grafana_data/ and influxdb_data/ on the host. To start completely fresh, stop the stack and remove those directories:

docker compose down
rm -rf grafana_data/* influxdb_data/*
docker compose up -d --build

Software versions

Component	Version
Ubuntu	26.04 LTS (collectd base image)
InfluxDB	1.12 (v2+ removed the native collectd UDP listener)
Grafana	13.0.1
collectd	system package
fritzcollectd	0.7.0 (pinned)
fritzconnection	0.8.5 (pinned; patched for lxml ≥5)
Python	3

Patches applied to upstream dependencies

fritzconnection-lxml5.patch — fritzconnection 0.8.x + lxml ≥5 compatibility

File: collectd-fritzbox/fritzconnection-lxml5.patch
Applied to: fritzconnection 0.8.x (fritzconnection/fritzconnection.py)
Applied during: Docker image build (collectd-fritzbox/Dockerfile)

The problem

fritzconnection 0.8.x fetches TR-064 XML configuration files from the FritzBox using lxml. In FritzXmlParser.__init__:

source = 'http://192.168.178.1:49000/igddesc.xml'
tree = etree.parse(source)   # lxml fetches the URL directly
self.root = tree.getroot()

lxml ≥5.0 (released ~2024) introduced a security hardening change: it no longer allows etree.parse() to fetch remote HTTP URLs. It raises:

OSError: failed to load "http://192.168.178.1:49000/igddesc.xml": Attempt to load network entity

Ubuntu 24.04 ships with lxml ≥5, so any fresh install pulls the incompatible version. The FritzBox is perfectly reachable — the issue is entirely inside Python.

Call flow

Before (broken with lxml ≥5):

FritzConnection.__init__()
  └─ _read_descriptions()
       └─ FritzDescParser(address, port, 'igddesc.xml')
            └─ FritzXmlParser.__init__()
                 ├─ builds source = "http://192.168.178.1:49000/igddesc.xml"
                 └─ etree.parse(source)  ← lxml ≥5 BLOCKS this, raises OSError
                      ↓
                 fritzcollectd catches OSError → "Failed to connect"

After the patch:

FritzConnection.__init__()
  └─ _read_descriptions()
       └─ FritzDescParser(address, port, 'igddesc.xml')
            └─ FritzXmlParser.__init__()
                 ├─ builds source = "http://192.168.178.1:49000/igddesc.xml"
                 ├─ detects it starts with "http"
                 ├─ requests.get(source)  ← plain HTTP fetch, always worked
                 └─ etree.fromstring(response.content)  ← parse bytes in memory, no URL loading
                      ↓
                 self.root populated correctly → collectd reads FritzBox data

The else branch keeps etree.parse(source) for the local-file case (used in unit tests where a filename path is passed instead of an address).

Why the patch lives in the Dockerfile

fritzconnection 0.8.5 is abandoned (last release 2018) and its API changed incompatibly in 1.0, which fritzcollectd 0.7.0 doesn't support. Upgrading either package would require rewriting the collectd plugin config. The patch is the minimal surgical fix.