- Docker – Writing a Dockerfile
The instructions that actually matter: `FROM`, `WORKDIR`, `COPY`, `RUN`, `ENV`, `EXPOSE`, `USER`, and the `CMD` versus `ENTRYPOINT` distinction that trips up everyone once. Built up line by line into the real Dockerfile that produces the pizza API image.
- Hasura – What It Is and Why It Exists
Start here. What Hasura actually does — point it at a Postgres database and get a GraphQL API with filtering, pagination, relationships and permissions without writing a resolver — and, just as important, what it does not do. Why v2 and v3 (DDN) are two different products rather than two releases of one, the exact versions this track is written against, the booking app every example comes from, and the full lesson index in reading order.
- Java String
String is the type you will use more than any other, and it has one property that explains nearly all of its behaviour: a String is immutable . Once created, its characters can never change. Every method that appears to modify a string actually returns a new one. Immutability, and what it means in…
- Spring Boot – Configuration, Profiles and Properties
Where configuration comes from and which source wins, @Value versus @ConfigurationProperties and why typed records beat scattered strings, profiles for local versus production, and how to keep secrets out of the repository without making the app impossible to run.
- Java Operators
Operators are the symbols that do things to values. Most of them behave exactly as you would guess from school arithmetic. This post covers all of them quickly, then spends its time on the four that do not behave as you would guess — which is where the bugs are. Arithmetic Trap 1: integer division…