How to add a cron job in Linux?

How to add a cron job in Linux?

February 17, 2024Posted inSRE, Tutorials
Every day we perform chronic tasks, akin to Unix Cron jobs that automate recurring tasks on a schedule. Users define jobs in a 'crontab' with a specific syntax, utilizing special characters for precise timing. An example job to run hourly is "0 * * * * /opt/aggregator/job.sh". To add a job, edit 'cronjob1' with a text editor, then load it using 'crontab cronjob1'. Verify it with 'crontab -l'. Monitoring cron jobs is crucial for SREs, a topic for a future post.
Inserting custom code to WordPress Header/Footer

Inserting custom code to WordPress Header/Footer

February 16, 2024Posted inObservability, Tutorials
Inserting code into WordPress headers/footers requires caution due to security risks. Legitimate reasons include tracking, ads, and SEO. Direct PHP edits are risky; using compatible plugins is safer. WPCode can insert code without manual theme edits. Ensure compatibility with WordPress versions and maintain updates. The WPCode plugin simplifies this process. Compatibility with WordPress 6.4.3 and eG Innovations 7.2.
Removing Amazon LightSail VMs properly without billing leakage

Removing Amazon LightSail VMs properly without billing leakage

February 15, 2024Posted inCloud Computing, Tutorials
Creating and tearing down a Virtual Private Server on Amazon LightSail involves not only the server but also its related resources like public IP, DNS zones, containers, storages, and databases to avoid additional charges. Users should methodically delete instances, containers, databases, static IP, and DNS zones to prevent unexpected costs and clean up the environment.
How to access JMX port of Docker container from outside?

How to access JMX port of Docker container from outside?

February 13, 2024Posted inDevOps, java, Tutorials
JMX is a Java API for managing Java applications, used for monitoring and performance control. The post details steps to containerize a Spring Boot application including setting up the JMX port within a Docker container. Additional parameters in `Dockerfile` and `management.properties` are provided, and instructions are given for building the image, running the container, exposing ports via the Linux firewall, and connecting with JMX clients, with a note that while the web port is accessible, JMX client connection issues are pending resolution.
3 Steps to containerize your Spring Boot Application

3 Steps to containerize your Spring Boot Application

February 12, 2024Posted inDevOps, java, Tutorials
Spring Boot's popularity stems from its ease of creating standalone, production-ready applications and its support for container environments, featuring auto-configuration and embedded web servers. Moreover, a large developer community offers support. The post demonstrates containerizing a simple Spring Boot app using Docker in three steps: creating a Dockerfile, building a Docker image, and running a Docker container. The process includes setting up the Java environment, exposing ports, and specifying runtime commands. The successful deployment allows access to the application via port mapping between the host and the container.
Docker installation on Linux

Docker installation on Linux

February 11, 2024Posted inDevOps, Tutorials
Docker is a platform that uses containers to streamline app development and deployment. This guide details Docker installation on Linux, comparing containerization to KVM, a full virtualization solution. While Docker Desktop requires KVM, Docker CE on servers does not. The tutorial concludes by demonstrating a successful Docker installation with a 'hello-world' test.
getting started with observability

Getting started with observability

February 8, 2024Posted inCloud Computing, Observability, Tutorials
This tutorial explains monitoring cloud infrastructure using eG Innovations' SaaS, detailing steps from signing up for a trial to monitoring AWS cloud instances. The process, utilizing a remote agent, covers discovering cloud resources, installing agents for converged monitoring (Metrics, Events, Logs, Traces), and receiving alerts for anomalies. Observability without writing scripts through Metrics-Events-Logs-Traces (MELT) is emphasized, with the promise to later discuss different monitoring methods.