Simon Willison’s Weblog


Tuesday, 30th January 2024

Beej’s Guide to Networking Concepts (via) Beej’s Guide to Network Programming is a legendary tutorial on network programming in C, continually authored and updated by Brian “Beej” Hall since 1995.

This is NOT that. Beej’s Guide to Networking Concepts is brand new—started in March 2023—and illustrates a whole bunch of networking concepts using Python instead of C.

From the forward: “Is it Beej’s Guide to Network Programming in Python? Well, kinda, actually. The C book is more about how C’s (well, Unix’s) network API works. And this book is more about the concepts underlying it, using Python as a vehicle.” # 10:08 pm

pgroll (via) “Zero-downtime, reversible, schema migrations for Postgres”

I love this kind of thing. This one is has a really interesting design: you define your schema modifications (adding/dropping columns, creating tables etc) using a JSON DSL, then apply them using a Go binary.

When you apply a migration the tool first creates a brand new PostgreSQL schema (effectively a whole new database) which imitates your new schema design using PostgreSQL views. You can then point your applications that have been upgraded to the new schema at it, using the PostgreSQL search_path setting.

Old applications can continue talking to the previous schema design, giving you an opportunity to roll out a zero-downtime deployment of the new code.

Once your application has upgraded and the physical rows in the database have been transformed to the new schema you can run a --continue command to make the final destructive changes and drop the mechanism that simulates both schema designs at once. # 9:27 pm

urllib3 2.2.0. Highlighted feature: “urllib3 now works in the browser”—the core urllib3 library now includes code that can integrate with Pyodide, using the browser’s fetch() or XMLHttpRequest APIs to make HTTP requests (to CORS-enabled endpoints). # 4:31 pm