Using Terraform is a great way to manage infrastructure as code. To map all the different types of resources in a deployment, Terraform uses plugins. Plugins are executable binaries written in Go that communicate with Terraform Core via an RPC interface. Each plugin provides an implementation for a specific service.

Sometimes there is no specific plugin for a service, but if the service provides a REST API, the generic REST API provider can be helpful. This time, I was looking for a way to manage DNS records on a Univention Corporate Server (UCS) using Terraform. The Univention Directory Manager (UDM) API is well documented and can be used with the RESP API provider, but there are a few minor pitfalls to be aware of.

Terraform is an open source infrastructure-as-code tool for creating, modifying, and extending infrastructure in a secure and predictable way. Terraform needs to store a state about the managed infrastructure and configuration. This state is used by Terraform to map real-world resources to your configuration and track metadata. By default, this state is stored in a local file, but it can also be stored remotely.

Terraform supports multiple remote backend provider including S3. I already use Backblaze for backups and have had good experiences with it. Since Backblaze also provides an S3 Compatible API, I wanted to use it for Terraform. How to use S3 as a state backend is well documented, but as it’s focused on Amazon S3 there are a few things to take care of. A basic working configuration will look like this:

Sometimes it can be helpful if single actions or entire automation in your Home Automation can be triggered with a physical button and not only from the Web UI. I’m using Zigbee2MQTT as a generic Zigbee to MQTT bridge as it supports a lot of different Zigbee devices and integrates flawlessly into Home Assistant. As I have a lot of different Tradfri Lamps in use already, I have bought a few of the Tradfri Shortcut Button (E1812).

Graylog is a centralized log management solution to capture, store and analyze log files in real-time. Starting with the latest minor release 4.3 Graylog announced to no longer support Elasticsearch (ES) due to licensing and structural changes Elastic introduced in v7.11. For this reason, the last supported ES version is 7.10, which has already reached EOL on May 11, 2022.

Telegraf is a powerful, plugin based metrics collector that also provides Prometheus compatible outputs. For various purposes, there are a number of input plugins that can collect metrics from various sources. Even more powerful are the processor plugins that allow metrics to be processed and manipulated as they pass through, and immediately output results based on the values they process. In this short blog post I’ll explain how to fetch JSON metrics from the Docker registry API to track some data of a DockerHub Repository.