Installing Caddy 2 on Amazon Linux 2
aws aws-ec2
Notes about installation problems

Relevant Whitespace in Markdown Lists
Have “fun” with some spurious spaces in Markdown lists.

Email Standards – basic and lesser known
What was SMTP, SPF, DKIM, DMARC, SRS and ARC again? …

Long term code
code-fun java
Sometimes you discover code which excels in thinking really long-term: …

Dynamic DNS with AWS Route 53 – the Good, the Bad and the Ugly
What to do with an AWS account, an own domain and the desire to fiddle with some AWS services? One obvious thing is to abandon dynamic DNS services like FreeDNS and host the names of two DSL routers (a Fritz!Box 9490 and a Fritz!Box 3270) in Route 53. So what are the options? …

Fritz!Box DynDNS – some gory details
Fritz!Box DynDNS
Usually a Fritz!Box can use existing Dynamic DNS services like DynDNS or No-IP without problems. It supports a bunch of predefined services but you can also specify a custom URL with some placeholders. The “fun” started when/if I wanted to implement a custom DynDNS service for my own domain and had to find out some non-obvious things. …

Setup a new PostgreSQL database on AWS-RDS
postgresql aws aws-rds
There are some differences between self-hosted Postgres and an AWS-RDS instance. Show how to setup a new database with a separate “owner” user. …

Date Gettime
code-fun java
Bad code with currentMillis

Boolean to String
code-fun java
Bad code with Boolean

Useless throwing Exceptions
code-fun java
Bad code with try/throw/catch

Synchronized New Object
code-fun java
My favorite “baddest piece of code encountered” is this one: …