What Are Extensions?
Dynatrace Extensions 2.0 let you monitor anything Dynatrace doesn't cover out of the box — network switches, firewalls, UPS devices, custom APIs. You write a YAML file, Dynatrace does the rest.
Two flavors:
- SNMP — Pure YAML. Polls network devices. This course.
- Python — Custom code for REST APIs, CLI, etc. Next course.
The Extension File
Every extension starts with extension.yaml. Here's the minimum:
name: custom:com.dynatrace.extension.my-device
version: 0.0.1
minDynatraceVersion: "1.318.0"
author:
name: Your Name
Rules: name starts with custom:, version is major.minor.patch, minDynatraceVersion is in quotes.
Fill in the 3 header fields. Remember: name starts with custom:, version is X.Y.Z, and minDynatraceVersion needs quotes.
How It Works
Your extension.yaml → Upload to Dynatrace → EEC polls the device → Metrics flow in → Entities appear → Screens show data
The EEC (Extension Execution Controller) runs on an ActiveGate. It reads your YAML, polls SNMP devices on a schedule, and sends metrics to Dynatrace.
What's in the Package?
bundle.zip (what you upload)
├── extension.zip
│ ├── extension.yaml ← your code
│ ├── snmp/ ← MIB files (if needed)
│ └── dashboards/ ← dashboard JSON
└── extension.zip.sig ← digital signature
Adding SNMP Polling
To actually collect data, add an snmp: section. This tells Dynatrace what to poll:
snmp:
- group: Device Default
interval:
minutes: 1
dimensions:
- key: device.address
value: this:device.address
This polls every 1 minute and captures the device IP. No metrics yet — we'll add those next.
Add a sys.name dimension that reads the device hostname. The OID is 1.3.6.1.2.1.1.5.0 — use the oid: prefix.
What's Next
In Module 1, you'll learn about OIDs — the "addresses" that tell SNMP which data to read from a device. Then in Module 2, you'll turn those OIDs into real metrics.