pict-rs/releases/0.4.0.md

pict-rs 0.4.0

I am excited to announce a new stable version of pict-rs, version 0.4.0. There's a few big things in 0.4 that might be exciting to developers and admins. Below you'll find a list of changes from 0.3 to 0.4.

Overview

Headline Features:

• Reworked Configuration
• Reworked Commandline
• Object Storage
• Backgrounded Uploads
• Full Video

Other Features:

• Published Dependencies
• HEAD Endpoints
• Healthcheck Endpoints
• Image Preprocessing
• GIF configuration
• JXL and AVIF
• H265, VP8, VP9, and AV1
• 404 Image
• DB Export
• Variant cleanup endpoint
• Client pool configuration

Fixes

• GIF/webm Transparency
• Image Orientation
• io_uring file write
• Blur Sigma

Removals

• Purge by disk name
• Aliases by disk name

Upgrade Notes

TODO

Descriptions

Reworked Configuration

Starting off with the most important information for server admins: The configuration format has changed. The pict-rs.toml is now far better organized, and includes more configuration options than before. Every field has been moved, so please take a look at the example pict-rs.toml file for information on how configuration works in 0.4.

Notable changes:

• RUST_LOG no longer has an effect, see PICTRS__TRACING__LOGGING__TARGETS and PICTRS__TRACING__OPENTELEMETRY__TARGETS for configuring log levels.
• PICTRS__ADDRESS has become PICTRS__SERVER__ADDRESS
• PICTRS__PATH has become PICTRS__OLD_DB__PATH, PICTRS__REPO__PATH and PICTRS__STORE__PATH

Reworked Commandline

Also notable for server admins: the commandline interface has changed. All configuration that can be expressed via the pict-rs.toml file or related environment variables can be set via the commandline as well.

Running the pict-rs server now requires invoking the run subcommand. Here are some examples:

$ pict-rs run
$ pict-rs -c /etc/pict-rs.toml run
$ pict-rs run filesystem -p /path/to/files sled -p /path/to/metadata

There is one flag that I will call out here: --save-to <path>. This can be incredibly helpful when debugging pict-rs. It dumps the configuration that pict-rs is currently using to a file of your choosing. Example:

$ PICTRS__SERVER__ADDRESS=127.0.0.1:1234 pict-rs --save-to debug.toml run
CTRL^C
$ cat debug.toml

It can also be useful to save your existing commandline arguments into a reusable configuration:

$ pict-rs --save-to config.toml \
    --log-targets warn \
    --log-format json \
    --console-address '127.0.0.1:6669' \
    --opentelemetry-url 'http://localhost:4317' \
    run \
        -a '127.0.0.1:1234' \
        --api-key "$API_KEY" \
        --client-pool-size 10 \
        --media-max-width 200 \
        --media-max-height 200 \
        --media-max-file-size 1 \
        --media-enable-full-video true \
        --media-video-codec av1 \
        --media-format webp \
    filesystem \
        -p /opt/pict-rs/files \
    sled \
        -p /opt/pict-rs/metadata \
        -e /opt/pict-rs/exports
CTRL^C
$ cat config.toml
$ pict-rs -c config.toml run

Object Storage

This is the biggest feature for pict-rs 0.4, but it isn't new. pict-rs 0.3 had initial support for uploading to object storage hidden behind the object-storage compile flag. My docker images and provided binaries did not enable this feature, so only folks compiling from source could even have tried using it. In 0.4 I am now much more confident in the object storage support, and use it myself for my personal setup.

Although pict-rs now supports object storage as a backend for storing uploaded media, it doesn't support generating URLs that bypass the pict-rs server for serving images. I've seen this misconception a couple times during the release candidate process and I would like to put these rumors to rest.

Using object storage when you're in a cloud environment is sensible. The cost for adding object storage is far less than for adding block storage, and although there are egress fees, they are typically very low. Admins currently running pict-rs on a VPS should consider moving to object storage if they find their disk usage is quickly growing.

Using object storage does not fully remove pict-rs' dependence on a local disk. pict-rs stores its metadata in an embedded key/value store called sled, which means it still requires disk access to function.

For new admins, using object storage from the start might be worth considering, but is not required. pict-rs provides a built-in migration path for moving from filesystem storage to object storage, which is documented in the pict-rs readme.

Backgrounded Uploads

This feature is important for keeping pict-rs fast. Since media needs to be processed on upload, upload times may grow long. This is especially true when considering pict-rs' other new features like full video and image preprocessing.

Backgrounded uploads work by deferring the image processing work to a background task in pict-rs, and responding to the upload HTTP request as soon as the provided file has been stored successfully. Instead of returning a file alias like the inline upload endpoint, it instead returns a UUID that represents the current upload process. That UUID can be given to a new claim endpoint to retrieve the uploaded media's alias, or an error in the event the media was rejected or failed to process. The claim endpoint uses a technique called "long polling" in order to notify clients on completion of the background processing. Clients can request to claim uploaded media as soon as the backgrounded endpoint reponds with an upload ID, and the server will hold the connection open for at most 10 seconds while it waits for processing to complete. If processing did not complete in time, the client can request again to claim the upload.

Full Video

pict-rs now supports uploading video with audio. In 0.3, pict-rs would always strip audio from uploaded videos. This was intended as a gif-like feature, since pict-rs' primary use is for storing pictures and not videos. By default, full video is disabled in pict-rs 0.4, but server admins can opt into full video uploads by setting PICTRS__MEDIA__ENABLE_FULL_VIDEO=true.

Along with supporting full video, an additional configuration option has been added to help keep down on file sizes and processing time: PICTRS__MEDIA__MAX_FRAME_COUNT. This option limits how many frames an uploaded video is allowed to have, rejecting the upload if it exceeds the provided value.

It is important to note that while pict-rs is capable of storing videos, it's processing functionality is limited to just the video's thumbnail.

Published Dependencies

pict-rs 0.3's experimental object storage support relied on a custom fork of the rust-s3 library, which did useful things like enable re-use of an HTTP Client between connections, and making the Client a trait, so it could be implemented for any arbitrary HTTP Client. Since then, the PR that was meant to upstream those changes was closed, and so pict-rs needed to find a replacement that suited it's needs.

pict-rs now relies on the rusty-s3 library for enabling object storage. This library takes a sans-io approach, and was simple to integrate with awc, my HTTP Client of choice.

HEAD Endpoints