19 items tagged “asgi”
2023
asgi-replay. As part of submitting LLM to Homebrew core I needed an automated test that demonstrated that the tool was working—but I couldn’t test against the live OpenAI API because I didn’t want to have to reveal my API token as part of the test. I solved this by creating a dummy HTTP endpoint that simulates a hit to the OpenAI API, then configuring the Homebrew test to hit that instead. As part of THAT I ended up building this tiny tool which uses my asgi-proxy-lib package to intercept and log the details of hits made to a service, then provides a mechanism to replay that traffic.
Writing a chat application in Django 4.2 using async StreamingHttpResponse, Server-Sent Events and PostgreSQL LISTEN/NOTIFY (via) Excellent tutorial by Víðir Valberg Guðmundsson on implementing chat with server-sent events using the newly async-capable StreamingHttpResponse from Django 4.2x.
He uses PostgreSQL’a LISTEN/NOTIFY mechanism which can be used asynchronously in psycopg3—at the cost of a separate connection per user of the chat.
The article also covers how to use the Last-Event-ID header to implement reconnections in server-sent events, transmitting any events that may have been missed during the time that the connection was dropped.
datasette-granian (via) Granian is a new Python web server—similar to Gunicorn—written in Rust. I built a small plugin that adds a “datasette granian” command starting a Granian server that serves Datasette’s ASGI application, using the same pattern as my existing datasette-gunicorn plugin.
2022
Deploying Python web apps as AWS Lambda functions. After literally years of failed half-hearted attempts, I finally managed to deploy an ASGI Python web application (Datasette) to an AWS Lambda function! Here are my extensive notes.
Weeknotes: Datasette Lite, nogil Python, HYTRADBOI
My big project this week was Datasette Lite, a new way to run Datasette directly in a browser, powered by WebAssembly and Pyodide. I also continued my research into running SQL queries in parallel, described last week. Plus I spoke at HYTRADBOI.
[... 1,434 words]Automatically opening issues when tracked file content changes
I figured out a GitHub Actions pattern to keep track of a file published somewhere on the internet and automatically open a new repository issue any time the contents of that file changes.
[... 1,211 words]2021
Weeknotes: sqlite-utils updates, Datasette and asgi-csrf, open-sourcing VIAL
Some work on sqlite-utils, asgi-csrf, a Datasette alpha and we open-sourced VIAL.
Notes on streaming large API responses
I started a Twitter conversation last week about API endpoints that stream large amounts of data as an alternative to APIs that return 100 results at a time and require clients to paginate through all of the pages in order to retrieve all of the data:
[... 1,692 words]2020
Weeknotes: datasette-ics, datasette-upload-csvs, datasette-configure-fts, asgi-csrf
I’ve been preparing for the NICAR 2020 Data Journalism conference this week which has lead me into a flurry of activity across a plethora of different projects and plugins.
[... 834 words]Async Support—HTTPX (via) HTTPX is the new async-friendly HTTP library for Python spearheaded by Tom Christie. It works in both async and non-async mode with an API very similar to requests. The async support is particularly interesting—it’s a really clean API, and now that Jupyter supports top-level await you can run ’(await httpx.AsyncClient().get(url)).text’ directly in a cell and get back the response. Most excitingly the library lets you pass an ASGI app directly to the client and then perform requests against it—ideal for unit tests.
2019
Logging to SQLite using ASGI middleware
I had some fun playing around with ASGI middleware and logging during our flight back to England for the holidays.
[... 2,535 words]Datasette 0.31. Released today: this version adds compatibility with Python 3.8 and breaks compatibility with Python 3.5. Since Glitch support Python 3.7.3 now I decided I could finally give up on 3.5. This means Datasette can use f-strings now, but more importantly it opens up the opportunity to start taking advantage of Starlette, which makes all kinds of interesting new ASGI-based plugins much easier to build.
Single sign-on against GitHub using ASGI middleware
I released Datasette 0.29 last weekend, the first version of Datasette to be built on top of ASGI (discussed previously in Porting Datasette to ASGI, and Turtles all the way down).
[... 1,612 words]datasette-cors (via) My other Datasette ASGI plugin: this one wraps my asgi-cors project and lets you configure CORS access from a list of domains (or a set of domain wildcards) so you can make JavaScript calls to a Datasette instance from a specific set of other hosts.
datasette-auth-github (via) My first big ASGI plugin for Datasette: datasette-auth-github adds the ability to require users to authenticate against the GitHub OAuth API. You can whitelist specific users, or you can restrict access to members of specific GitHub organizations or teams. While it’s structured as a Datasette plugin it also includes ASGI middleware which can be applied to any ASGI application.
Porting Datasette to ASGI, and Turtles all the way down
This evening I finally closed a Datasette issue that I opened more than 13 months ago: #272: Port Datasette to ASGI. A few notes on why this is such an important step for the project.
[... 1,082 words]asgi-cors (via) I’ve been trying out the new ASGI 3.0 spec and I just released my first piece of ASGI middleware: asgi-cors, which lets you wrap an ASGI application with Access-Control-Allow-Origin CORS headers (either “*” or dynamic headers based on an origin whitelist).
Hello world for ASGI running on Glitch (via) I’m continuing to experiment with Python 3 running on Glitch. This evening on my walk home from work I built this “hello world” demo on my phone, partly to see if Glitch was a workable mobile development environment—it passed with flying colours! The demo is a simple hello world implemented using the new ASGI 3.0 specification, running on the daphne reference server. Click the “via” link for my accompanying thread on Twitter, which includes a short screencast (also recorded on my phone) showing Glitch in action.
2018
The ASGI specification provides an opportunity for Python to hit a productivity/performance sweet-spot for a wide range of use-cases, from writing high-volume proxy servers through to bringing large-scale web applications to market at speed.