10 items tagged “thomas-ptacek”
2024
Run a prompt to generate and execute jq programs using llm-jq
llm-jq is a brand new plugin for LLM which lets you pipe JSON directly into the llm jq command along with a human-language description of how you’d like to manipulate that JSON and have a jq program generated and executed for you on the fly.
Making Machines Move. Another deep technical dive into Fly.io infrastructure from Thomas Ptacek, this time describing how they can quickly boot up an instance with a persistent volume on a new host (for things like zero-downtime deploys) using a block-level cloning operation, so the new instance gets a volume that becomes accessible instantly, serving proxied blocks of data until the new volume has been completely migrated from the old host.
Macaroons Escalated Quickly (via) Thomas Ptacek’s follow-up on Macaroon tokens, based on a two year project to implement them at Fly.io. The way they let end users calculate new signed tokens with additional limitations applied to them (“caveats” in Macaroon terminology) is fascinating, and allows for some very creative solutions.
2023
Carving the Scheduler Out of Our Orchestrator (via) Thomas Ptacek describes Fly’s new custom-built alternative to Nomad and Kubernetes in detail, including why they eventually needed to build something custom to best serve their platform. In doing so he provides the best explanation I’ve ever seen of what an orchestration system actually does.
2022
[SQLite is] a database that in full-stack culture has been relegated to "unit test database mock" for about 15 years that is (1) surprisingly capable as a SQL engine, (2) the simplest SQL database to get your head around and manage, and (3) can embed directly in literally every application stack, which is especially interesting in latency-sensitive and globally-distributed applications.
Reason (3) is clearly our ulterior motive here, so we're not disinterested: our model user deploys a full-stack app (Rails, Elixir, Express, whatever) in a bunch of regions around the world, hoping for sub-100ms responses for users in most places around the world. Even within a single data center, repeated queries to SQL servers can blow that budget. Running an in-process SQL server neatly addresses it.
SOC2 is about the security of the company, not the company’s products. A SOC2 audit would tell you something about whether the customer support team could pop a shell on production machines; it wouldn’t tell you anything about whether an attacker could pop a shell with a SQL Injection vulnerability.
2021
API Tokens: A Tedious Survey. Thomas Ptacek reviews different approaches to implementing secure API tokens, from simple random strings stored in a database through various categories of signed token to exotic formats like Macaroons and Biscuits, both new to me.
Macaroons carry a signed list of restrictions with them, but combine it with a mechanism where a client can add their own additional restrictions, sign the combination and pass the token on to someone else.
Biscuits are similar, but “embed Datalog programs to evaluate whether a token allows an operation”.
2020
Sandboxing and Workload Isolation (via) Fly.io run other people’s code in containers, so workload isolation is a Big Deal for them. This blog post goes deep into the history of isolation and the various different approaches you can take, and fills me with confidence that the team at Fly.io know their stuff. I got to the bottom and found it had been written by Thomas Ptacek, which didn’t surprise me in the slightest.
How CDNs Generate Certificates. Thomas Ptacek (now at Fly) describes in intricate detail the challenges faced by large-scale hosting providers that want to securely issue LetsEncrypt certificates for customer domains. Lots of detail here on the different ACME challenges supported by LetsEncrypt and why the new tls-alpn-01 challenge is the right option for operating at scale.
2007
A Roundup Of Leopard Security Features (via) Thomas Ptacek’s overview of the new security features in Leopard. Guest Accounts are worthless from a security P.O.V., but I still plan to use one for our PowerBook that’s now just a media player.