Skip to content

2024

  • in Linux
  • 3 min read

How to Verify Email Delivery to a Remote Mail Server: A Step-by-Step Guide

Ensuring that an email reaches its intended recipient’s mail server is crucial for effective communication. One way to manually verify this is by using Telnet to simulate the sending process. Below, we provide a detailed guide on how to use Telnet to check if a remote mail server is set up to receive emails for a specific mailbox. We will also include possible responses from the mail server, both correct and incorrect, to help you troubleshoot common issues such as spam filters, full mailboxes, and more.

  • in Linux
  • 2 min read

How to Fix Yum Error Caused by Python Version Conflict on CentOS

Are you encountering the following error when trying to use yum on your CentOS system?

File "/bin/yum", line 30
except KeyboardInterrupt, e:
^
SyntaxError: invalid syntax

This error typically occurs when the default Python interpreter has been switched from Python 2 to Python 3. Since yum relies on Python 2, pointing the /usr/bin/python symlink to Python 3 causes syntax incompatibilities. In this article, we’ll guide you through resolving this issue and restoring your system’s package manager to working order.

  • in Linux
  • 2 min read

How to Secure SSHD Configuration to Prevent Unauthorized Access

Securing your server’s SSH daemon (SSHD) is crucial to protect against unauthorized access and potential security threats. In this article, we’ll explore the best practices for SSHD configuration, specifically focusing on methods to enhance security by leveraging public key authentication, disabling password authentication, preventing empty passwords, disallowing root login via SSH, and specifying the location for authorized keys. These settings ensure a robust defense mechanism for your server’s SSH access.

  • in Devops
  • 2 min read

How to Debug HTTP Headers Using Nginx: A Step-by-Step Guide

Debugging HTTP headers is a crucial task for many web developers and system administrators. This guide will walk you through setting up Nginx to capture and inspect HTTP headers in real-time. Understanding how to efficiently debug these headers using Nginx can save you time and help troubleshoot issues more effectively.

  • in Devops
  • 1 min read

Resolving Elasticsearch Service Token Authentication Error

Elasticsearch, a widely used open-source search and analytics engine, often requires the creation of service tokens for authentication purposes. These tokens are typically generated via the command-line interface (CLI) without any issues. However, a recurring problem has been identified when these tokens are used with curl or other types of authentication methods, such as Kibana login.

The error message received is as follows:

received token fails with error
cannot authenticate with auth token to Elasticsearch, error: failed to authenticate service account [elastic/kibana] with token name [<token name>]