DevOps

Introduction

Unlike Caddy, which focuses on simplicity, Traefik (pronounced Traffic) was built to solve one specific task: routing traffic in dynamic environments.

It is a reverse proxy and load balancer designed specifically for Docker, Kubernetes, and other orchestrators. The main difference from Nginx is not static configuration, but the ability to automatically discover and serve services.

Key Concepts: Dynamic Configuration

The philosophy of Traefik is built on the principle of Service Discovery.

Introduction

Logrotate is a powerful tool for log management in Linux, but its interaction with Docker has its own specifics. This guide explains how to properly use logrotate with Docker containers and when it’s better to rely on Docker’s built-in log management tools.

Docker Containers and Logs

Docker collects logs from the standard output streams (stdout and stderr) of containers and, by default, stores them as JSON files:

/var/lib/docker/containers/\<container\_id>/\<container\_id>-json.log

If a container generates a lot of logs, these files can take up gigabytes and quickly consume all available disk space.

Introduction

In a world where setting up a web server often requires studying complex configuration files, Caddy offers a radically different approach. It is a modern, multifunctional web server, reverse proxy, and certificate authority in one package.

Caddy was created with a single goal: to provide maximum simplicity. If you are tired of the redundancy of Nginx or Apache, then Caddy is what you’re looking for. Its main “killer feature” is fully automatic SSL certificate management, making it an indispensable tool for developers.

Introduction: A Hidden Network Issue

Developers and system administrators using servers on the OpenStack platform (for example, the C*-M*-D* hosting plans from reg.ru) sometimes encounter mysterious network problems. The internet seems to work, but when trying to transfer large amounts of data or establish connections to certain services, requests may hang or fail due to timeouts.

The provider explains this issue as a feature of their infrastructure:

Servers on the OpenStack platform use VxLAN technology, which reserves 50 bytes for service information. Because of this, the maximum transmission unit (MTU) on the server’s main network interface (ens3) is 1450 bytes.

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Loki + Grafana: A Lightweight and Cost-Effective Logging Solution for the Cloud

We’re wrapping up our series on centralized logging with a modern and innovative solution: Loki together with Grafana. Developed by Grafana Labs, this stack reimagines how logging works — making it simple, efficient, and especially appealing for those already using Prometheus.

What Is Loki and How Does It Work?

Loki is a log aggregation system designed to minimize resource usage. It indexes only metadata (labels), while the log messages themselves are stored in compressed form — following the same philosophy as Prometheus, but for logs.

Graylog: A Flexible and User-Friendly Log Management Solution

We’ve already covered ELK Stack and OpenSearch — powerful logging tools with scalable architectures. Now let’s take a look at Graylog — a dedicated log management platform offering convenience, powerful processing, and flexible alerting.

What Is Graylog and How Does It Work?

Graylog is a centralized log management system designed for ease of use and rich capabilities. Unlike the ELK Stack, Graylog was built from the ground up as a unified platform.

We’ve explored the ELK Stack, its power — and, unfortunately, its licensing changes. These changes sparked debate within the open-source community and led to the creation of a worthy alternative — OpenSearch.

OpenSearch is a fully open-source fork of the last open versions of Elasticsearch and Kibana, released under the Apache 2.0 license. The project was initiated by Amazon Web Services (AWS) in 2021 and has since evolved as an independent open-source initiative under the OpenSearch Project.

ELK Stack (Elasticsearch, Logstash, Kibana): The Classic Stack for Log Collection and Analysis

After establishing that centralized logging is not just a convenience but a necessity, it’s time to dive into specific tools. Let’s start with one of the most well-known and widely adopted solutions in the logging world — the ELK Stack.

The ELK Stack is a set of three open-source components developed by Elastic. It provides a powerful, flexible, and scalable solution for log collection, processing, storage, search, and visualization.

Why Do We Need Centralized Logging? Making Sense of Log Chaos

We’ve already discussed the importance of metrics monitoring for understanding the health of your IT infrastructure. But metrics are only part of the picture. To truly understand what’s happening inside your systems and applications, you need logs.

Logs are records of events generated by operating systems, applications, network devices, and nearly any software component. They capture what, when, where, and why something happened. Think of them as the “black box” of your infrastructure — an invaluable source of information for debugging, auditing, and incident investigation.

In our series on monitoring systems, we’ve reviewed Munin, Prometheus with Grafana, and Zabbix. Now it’s time to talk about a solution that addresses one of the main pain points of Prometheus users — long-term, scalable, and efficient time-series storage. Meet VictoriaMetrics, a high-performance and cost-effective TSDB (time-series database) that perfectly complements the Prometheus ecosystem when paired with Grafana for visualization.

What Is VictoriaMetrics and Why Do You Need It?

Prometheus handles real-time monitoring and storage well, but its built-in TSDB isn’t designed for long-term retention or scaling to terabytes or petabytes of data. That’s where VictoriaMetrics comes in.