eu-grid-frequency-scraper

Important

The script only uses one source of information.

A simple Python script, that scrapes the current frequency of the EU-Grid from this API: https://dat.netzfrequenzmessung.de:9080/frequenz.xml. It sends alert-messages of two different types (WARNING or CRITICAL) when the parsed frequency has been reached or exceeded the configured thresholds.

Table of contents

• Table of contents
• Alert-Thresholds
  • WARNING Alert-Threshold
  • CRITICAL Alert-Threshold
• NTFY
• Netzfrequenz-API
• Installation
  • Prepare env & Install dependencies
• Usage
  • Create systemd-timed-service (recommended)
• Future plans

Alert-Thresholds

There are two types of configurable frequency Alert-thresholds:

• WARNING
• CRITICAL

WARNING Alert-Threshold

Env value-name	Default value	Description
WARNING_MIN_HZ_ALERT_THRESHOLD	"49.850"	The minimum frequency (in Hz) that triggers a WARNING alert.
WARNING_MAX_HZ_ALERT_THRESHOLD	"50.150"	The maximum frequency (in Hz) that triggers a WARNING alert.

CRITICAL Alert-Threshold

Env value-name	Default value	Description
CRITICAL_MIN_HZ_ALERT_THRESHOLD	"49.600"	The minimum frequency (in Hz) that triggers a CRITICAL alert.
CRITICAL_MAX_HZ_ALERT_THRESHOLD	"50.400"	The maximum frequency (in Hz) that triggers a CRITICAL alert.

NTFY

Note

NTFY is a simple HTTP-based pub-sub notification service.

It can be self-hosted: https://github.com/binwiederhier/ntfy

Env value-name	Default value	Description
ENABLE_NTFY	false	Whether to enable NTFY-alerts.
NTFY_TOPIC_URL	""	URL to the NTFY-topic where the alerts should be sent to. Required when ENABLE_NTFY=true.
NTFY_AUTH_TOKEN	""	Authentication-Token for the NTFY-topic. Required when ENABLE_NTFY=true
NTFY_HTTP_REQUEST_TIMEOUT	10	HTTP-request-timeout in seconds.
NTFY_HTTP_REQUEST_CERT_VERIFY	false	Whether to verify the SSL/TLS-Certificate of NTFY.

Netzfrequenz-API

Env value-name	Default value	Description
NETZFREQUENZ_DE_API_URL	""	URL to the netzfrequenzmessung.de-API.
API_HTTP_REQUEST_TIMEOUT	10	HTTP-request-timeout in seconds.
API_HTTP_REQUEST_CERT_VERIFY	true	Whether to verify the SSL/TLS-Certificate of the API-URL.

Installation

Prepare env & Install dependencies

python3 -m venv .venv && source .venv/bin/activate && pip3 install -r requirements.txt

Usage

.venv/bin/python3 scraper.py --help

Create systemd-timed-service (recommended)

# /etc/systemd/system/eu-grid-frequency-scraper.service
[Unit]
Description=eu-grid-frequency-scraper
After=network.target

[Service]
Type=simple
User=my-user
Group=my-user
WorkingDirectory=/home/my-user/eu-grid-frequency-scraper
ExecStart=/home/my-user/eu-grid-frequency-scraper/.venv/bin/python /home/my-user/eu-grid-frequency-scraper/scraper.py -l info
Restart=no
StandardOutput=journal
StandardError=journal

# /etc/systemd/system/eu-grid-frequency-scraper.timer
[Unit]
Description=Run eu-grid-frequency-scraper

[Timer]
# Every two minutes starting from the minute 0
OnCalendar=*:0/2
Unit=eu-grid-frequency-scraper.service
Persistent=true

[Install]
WantedBy=timers.target

Future plans

• Add time-values-database (e.g. influxdb)
  • Store parsed frequency and timestamp in db
  • Send (low priority) alert at the end of the day about lowest & highest 'measured' frequency