octoturgeandClaude Opus 5
4f37384706
Reporting a detected printer as `prusa_link` asserted a product nothing on
the wire mentions. What a probe observes is that something speaks the
OctoPrint REST API; PrusaLink is one implementation of it, OctoPrint itself
is another, and without a credential the two are indistinguishable - every
PrusaLink identity endpoint requires digest auth.
So discovery now reports `vendor = "octoprint"`, the protocol it actually
saw, and carries `ambiguous_with` so the rendered entry prints a comment
offering `prusa_link` directly above the `vendor` line. Changing it is a
one-word edit in the file the operator is already pasting into, which is the
right place for a question only they can answer. The exception is a body
that names itself: `/api/version`'s `text` field reads "PrusaLink 0.7.0" or
"OctoPrint 1.9.3", so on the rare unauthenticated 200 the answer is known
and no choice is offered.
For that to mean anything, `octoprint` had to become a vendor `fleet.rs`
accepts - otherwise discovery printed a block that would not load. It maps
to the same client as `prusa_link`, because they speak the same API, with an
`OctoPrintFlavour` recording which. The flavour is stored now, while the
client is still a stub, precisely because no probe can settle it: it is the
operator's answer, and without somewhere to keep it the real client would
have to ask them a second time. `PrusaLinkPrinter` is accordingly now
`OctoPrintPrinter` - one client for the API family - since a struct called
PrusaLink holding a flavour that says "Generic" is a contradiction someone
would later have to unpick.
**Found by the new test, and the reason it exists:** `fleet::load` did *not*
reject an entry whose credential was blank. `require_field` took an
`Option`, so `access_code = ""` arrived as `Some("")` and loaded happily -
which falsified the claim this feature was built on, that printing a block
with an empty credential is safe because pasting it in unfinished fails
loudly at startup. It does now. An empty credential is not a usable one; it
only moves the failure somewhere worse, where a Bambu printer is refused at
MQTT and a PrusaLink one 401s on every poll with nothing saying the field is
blank. This is the same trap as `??`-instead-of-`||` on an environment
variable that ships empty, which the backend's `auth/edge_secret.ts` and
`s3/index.ts` both document; it bites identically on a TOML key.
tests/discovery_to_fleet.rs is new and closes the loop: discovery and fleet
are coupled by nothing but a string, unit tests on either side cannot catch
a drift between them, and the symptom of a drift is an operator pasting in
exactly what they were told to and the gateway refusing to start. It renders
a candidate for every vendor, fills in the credential the way a human would,
loads it for real, and checks the handle matches the vendor asked for - not
merely that something loaded, since `octoprint` and `prusa_link` share a
client and a mapping that collapsed them would still load and still be
wrong.
Verification: the Moonraker probe now runs end to end over real HTTP against
a stand-in serving Moonraker's documented `/printer/info`, and correctly
reports a klipper entry named from the returned hostname. Port 80 cannot be
bound without root here, so the PrusaLink path is covered by a test that
takes a real socket answering a real digest challenge - the one link unit
tests on the classifier cannot reach, and the one PrusaLink is identified by.
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/). - Camera restreaming - generates go2rtc's configuration from the camera
URLs the printers report, and restarts go2rtc when it changes
(
src/camera.rs+src/go2rtc.rs). Only the X1/H2 class publishes an RTSP URL: confirmed against two real machines, an H2C reportsrtsps://<ip>:322/streaming/live/1and a P1P reports a camera with no URL for it. A P1/A1 camera needs Bambu's proprietary port-6000 JPEG stream, which this crate does not speak, so those printers advertise no stream rather than one that will not play. Note the stream is reachable on the gateway's LAN only - there is no relay. - 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 routes between the cloud and the printers
The uplink and the printer fleet are wired together, in both directions
(uplink/mod.rs):
- Up: every 5s, one
PrinterTelemetrysnapshot per printer that has reported, batched into a singleTelemetrymessage. Verified live against a P1P and an H2C. - Down: a
Commandfrom the cloud is looked up by our own printer id, executed, and answered with aCommandResult. The set of commands is deliberately small - a fan speed and a single gcode line - and deliberately has no "start a print" variant; seePrinterCommand.
One quirk worth knowing: a Bambu on protocol v1 only sends a complete
status when asked, so each telemetry tick also fires a pushing.pushall for
the next one. A v1 printer's telemetry is therefore one tick behind, which
is why it shows up on the second frame rather than the first.
What's still a stub
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. upload_file is proven, but
only with a small text file, not a multi-megabyte sliced .3mf.
PrusaLink (REST) and Klipper/Moonraker (WebSocket) - printer/prusa.rs
and printer/klipper.rs just println! what they'd send. Also not built
yet: local buffering for telemetry across connectivity gaps (so telemetry
produced while the uplink is down is simply lost), 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, camera config, watchdog and completion watcher 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
camera.rs Writes go2rtc's config from the camera URLs the printers report
go2rtc.rs Restarts the go2rtc camera-restreaming process if it dies, or when the config changes
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.