octoturgeandClaude Opus 5
1d95451c4c
Pointed at a real H2C that was 20% into a job, `print_status()` returned
nothing at all. The printer was in fact pushing a full status object every
second; every one was arriving, failing to deserialize, and being dropped
invisibly by an `if let Ok(report) = ..` with no `else`.
That silence produced two confidently-wrong claims in our own comments,
both corrected here:
- `pushall`'s doc said whether v2 emits `push_status` unprompted was "an
open question". It is not: v2 pushes a full 97-field object roughly once
a second from the moment you subscribe, no trigger needed. There is no
missing "other trigger" to hunt for.
- The "sequence gap" warning blamed the network for dropped v1 updates.
Those updates were not dropped in transit - they failed to parse, so
they never reached the counter, making the next one that did look like a
skip. Confirmed: seq 57, 62, 64 and 69 all arrived. After the fix, zero
gaps and zero parse failures across a 25s run against both printers.
Two concrete causes, both found with captured payloads:
- v1 trays carry `tray_temp`/`tray_time`; v2 trays carry
`drying_temp`/`drying_time`. All four were required, so *every* v1 push
carrying AMS data failed.
- A third tray shape existed that nothing modelled: an empty v2 slot sends
`{"id": "2", "state": 0}`, which matched neither `EmptyTray` (it denies
unknown fields, deliberately) nor `LoadedTray` (16 fields short).
A parse failure now reports itself, naming the printer, the sequence id and
the serde error. A report this process cannot parse is a defect in
`PrintReport`, and the only way to fix it is to be told which field.
`PrintReport` itself modelled 9 of 97 top-level fields, and none of them
were progress or temperature - it was built from a truncated example. It
now carries gcode_state, percent, layer counts, remaining time, nozzle/bed
temperatures, fan gears, wifi and HMS entries. `merge_from`'s two dozen
four-line blocks collapse to `newer.x.or(self.x.take())` one-liners: the
old shape made adding a field a three-place edit, and forgetting the merge
half produced a field that silently never survived a partial update.
Two scale traps documented where they bite: reported fan speeds are 0-15
gears, not percent and not the 0-255 PWM we send (`set_fan_speed(50)`
reads back as "7"); and v2 pins `sequence_id` to one value for minutes
while contents change, so it orders and identifies nothing there.
Two examples, and the distinction between them is the point. `live_reports`
is read-only and safe against a printer mid-job. `bambu_idle_checks`
writes, so it requires an explicit printer id and refuses to run unless
that printer reports `gcode_state: "IDLE"`.
Regression fixtures are verbatim captures off both printers, hardware
identifiers scrubbed - the only way to keep this from regressing without a
printer plugged in.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
continuum-proxy
Edge gateway daemon for the Continuum print farm platform. Runs on a Linux
SBC on-site, talks to printers over the LAN, and keeps a connection to the
cloud control plane (continuum-backend).
What's real right now
- Bambu MQTT - a real client for both protocol generations (MQTT
v3.1.1+BambuMQTT v1 on older firmware, MQTT v5+BambuMQTT v2 on current
firmware), auto-detected per printer on connect (a firmware update can
move the same physical printer between them, so this isn't something
config can hard-code once and forget - see
printer/bambu.rs'sBambuProtocolPreference::Auto). Request/reply correlation viasequence_id, an in-memoryprint.push_statuscache that merges v1's partial updates and replaces on v2's full ones, and TLS trust that auto-pins a printer's certificate via trust-on-first-connect the first time the bundled CA doesn't verify (printer/bambu.rs'sensure_trusted) - seeprinter/bambu_mqtt.rs's doc comment for the full protocol write-up. - Marlin/RepRap serial - a real held-open serial connection that paces
gcode lines by Marlin's own "ok" acknowledgment (
printer/marlin_serial.rs). - Wire shapes from schemas, not hand duplication - Bambu's raw MQTT
JSON is built straight from
continuum-schemas' JSON Schema files viacontinuum-schema-instance, instead of a second hand-written copy of every request shape drifting out of sync with the schema. - Cloud uplink - a WebSocket client to
continuum-backendthat connects, sends a heartbeat on a timer, and reconnects on drop (src/uplink/). - go2rtc watchdog - restarts the camera-restreaming subprocess if it
dies (
src/go2rtc.rs). - Bambu file upload - implicit FTPS (port 990) into the printer's own
cache/directory (src/printer/bambu_ftps.rs, viaBambuPrinter::upload_file). Confirmed live against a P1P on 2026-10-03: login, binary mode, and the transfer all work, byte count matched exactly. - Print status -
print.push_statusparsed intoPrintReportwith real job progress, temperatures, fans and HMS entries. Confirmed live on both generations (idle P1P on v1, H2C 20% into a job on v2); regression fixtures from those captures are intests/fixtures/.
Examples worth knowing
cargo run --example live_reports [printer-id]- read-only, safe against a printer that is mid-print. Connects, reports firmware, and watches the status stream. Redirect stderr to capture raw payloads.cargo run --example bambu_idle_checks -- <printer-id>- writes (FTPS upload, fan speed). Requires an explicit printer id and refuses to run unless that printer reportsgcode_state: "IDLE".
What's still a stub (cont.)
start_uploaded_file - the MQTT command that actually starts a print from
an uploaded file - is written but has deliberately never been fired, since
that commits a machine to hours of work. Its doc comment lists the three
details to confirm on the first real attempt.
What's still a stub
PrusaLink (REST) and Klipper/Moonraker (WebSocket) - printer/prusa.rs
and printer/klipper.rs just println! what they'd send. Also not built
yet: dispatching a cloud-issued command to a connected printer (the uplink
and the printer fleet run side by side in main.rs, but nothing routes
between them yet), local buffering for telemetry across connectivity gaps,
LAN printer discovery (SSDP/mDNS), and the mechanical plate-changer
interface.
Getting started
cp .env.example .env
cargo run # the daemon: connects every configured printer, then runs the cloud uplink + go2rtc watchdog
cp printers.example.toml printers.toml # fill in your real printers (gitignored)
cargo run --example auto_connect_bambu # checks/auto-pins each Bambu printer's certificate, no MQTT needed
cargo run --example test_bambu_certs # narrower: just the raw TLS handshake, no auto-pinning
cargo run --example printer_polymorphism # standalone trait+enum demo, fake data, no network/env needed
cargo run --example bambu_commands_demo # round-trips hand-written structs against real captured Bambu JSON
Structure
src/
main.rs Loads+connects the printer fleet, then runs the uplink and go2rtc watchdog side by side
config.rs Loads settings from environment variables
fleet.rs Loads printers.toml into ready-to-use PrinterHandles
uplink/ WebSocket client to continuum-backend: connect, heartbeat, reconnect on drop
go2rtc.rs Restarts the go2rtc camera-restreaming process if it dies
printer/
mod.rs GenericPrinter trait + PrinterBase + PrinterHandle enum - the trait+enum
"inheritance" pattern this project uses instead of class inheritance
bambu.rs The real Bambu printer type: cert trust, protocol version auto-detect, commands
bambu_mqtt.rs The real MQTT wiring underneath bambu.rs - see its doc comment for the protocol details
bambu_commands/ Hand-written serde structs mirroring continuum-schemas' bambulab/ shapes
marlin_serial.rs A real held-open Marlin/RepRap serial connection
prusa.rs, klipper.rs Still stubs - see "What's still a stub" above
examples/
auto_connect_bambu.rs Checks/auto-pins every Bambu printer's certificate (no MQTT)
test_bambu_certs.rs Narrower: just a raw TLS handshake per Bambu printer
printer_polymorphism.rs Standalone trait+enum demo, five fake printers, no network needed
bambu_commands_demo.rs Round-trips bambu_commands' structs against real captured Bambu JSON
printers.toml (gitignored - copy from printers.example.toml) holds real
per-printer connection details: host, access code/API key/serial port
depending on vendor, and - for Bambu - an optional per-printer CA
certificate override (see certs/README.md; most printers don't need one,
since connect() auto-pins automatically).
Learning Rust through this repo
src/printer/mod.rs's doc comment is where the "how do I do inheritance
without classes" question lives - trait (shared behavior) + struct
(shared fields) + enum (the closed set of concrete types), instead of
GenericPrinter -> BambuPrinter/PrusaLinkPrinter/... class inheritance.
Run printer_polymorphism to see it work end to end without needing any
real printer on the network.