Category: Infrastructure

Suppose you have to list all the tables of PostgreSQL database. You can achieve this by various means. [Read more...]

Amazon / AWS S3 is an object storage. You can imagine it as a cloud file system. This article shows you how you can download files from Amazon S3 to your local machine. [Read more...]

I have come accross this question many times: “If I delete a Postgres table, do I also have to delete it’s indexes, triggers and constraints before or afterwards?“. The short answer is no. When a table is dropped, Postgres will also delete it’s related indexes, triggers and constraints. In the following article a docker-compose.yml file and some code snippets are provided if you want to validate this behaviour. [Read more...]

TLS (X.509) certificates can be stored directly in a Kubernetes cluster using secrets. In this article you will find a nifty bash one-liner which allows you to examine the expiration dates of such certificates. [Read more...]

If you want to backup the emails from your Microsoft Office 365 mailbox you can utilize the execellent OfflineIMAP program. In this article I will outline how you can configure and use OfflineIMAP for this specific use case. [Read more...]

Recently I ran into a situation where log messages from a service implemented in Golang were missing from a Linux system. To be able to easily troubleshoot this problem and quickly iterate over possible solutions I utilized Docker and ran systemd inside a Docker container. [Read more...]

Suppose before starting a service you have to set an environment variable containing the current date and time. Furthermore this environment variable should only be propagated to the service you are just going to start. [Read more...]

Suppose you have to change the primary key of a PostgreSQL database. You can achieve this by executing the following statements: [Read more...]

When using ssh to connect to a server the ssh client checks the identity of the server by using one or more so called known_hosts files. In these files the public keys are stored on a host name or IP address basis. This article shows you how you can make proper use of this mechanism. [Read more...]

Current versions of Ubuntu and Kubuntu install a package named apt-btrfs-snapshot by default. This package creates a btrfs snapshot each time packages are installed or removed. These snapshots can take up a lot of space if not cleaned up regularly. [Read more...]