CHG-0033: An Album Asked For on the Bus


Date	2026-10-23
Change type	Upgrade
Status	In progress
Systems	The tenant’s services workload (`services.eds.mobile.deevnet.net`): the four services rebuilt and restarted. `dv02rpi002p01`, the relay: `npagent` replaced
How	`make -C deploy ship WHERE=builder` and `make -C deploy/relay push`, from the branch `voice-play-album`
Risk	Low. Most likely to go wrong: a service not coming back, which leaves the mobile site’s stand and screen without a current track until shipped again. The home back-end Pi is not touched
Decisions	ADR-0040, whose command this puts on the bus
Related	CHG-0032, the last change, made on the back-end Pi

Summary

play_album is the first command that chooses what plays (ADR-0040). npagent play-album has already played Van Halen’s first album from the relay by hand; this puts the same request behind the bus. nowplayd passes play_album to itunes whatever is current, and the iTunes driver asks for the album and then asks what plays.

Nothing in the settings changes: NP_ALBUM_SOURCE defaults to itunes. The workload is shipped from main with this branch’s two commits on it, so it also takes whatever has merged since it was last shipped.

Goal

The four services are active after the ship, and npagent after the push.
{"v":1,"command":"play_album","artist":"Van Halen","album":"Van Halen"} on eds/nowplaying/source/itunes/command plays the album, and current says Van Halen.
An album the library does not have is logged as driver.command_failed, “the library played no album by those names”.

Procedure

make -C deploy ship WHERE=builder.
make -C deploy status.
make -C deploy/relay push, then make -C deploy/relay status.
Publish the command above with nowplayd’s account, which may publish to a source’s command topic. No account yet may publish play_album to nowplaying/command but the cover screen’s; nowplayd’s routing of it is tested in internal/command and is proved when its sender has an account.
Publish one for an album not in the library.

Undo

Ship and push main again: git switch main, then the two commands above.

Outcome

When (UTC)	What happened
00:00:45–00:02:25	`ship WHERE=builder` from `22889ba`: the four images built on the Builder and loaded; all four services active at 00:02:24. nowplayd at once had iTunes playing Van Halen, “Ain’t Talkin’ ‘Bout Love”, and listed the Discogs collection (227 records).
00:02:49	`make -C deploy/relay push`: installed `22889ba`; `npagent` active, iTunes followed again.
00:02:57	`play_album` for Aerosmith by Aerosmith, asked for by the owner, published with nowplayd’s account on `eds/nowplaying/source/itunes/command`. Within a second the driver reported Aerosmith, “Make It”, the album’s first track, and nowplayd published it as `current`. At 00:02:59, after the check, the driver logged `command: play_album` as done.
00:23:00	Asked for by the owner: Guns N’ Roses’ first album, named by `cmd/discography` (ADR-0041) as Appetite for Destruction and published the same way. At 00:23:01 the driver reported “Welcome To The Jungle”, Appetite For Destruction, as the library capitalizes it; at 00:23:02 the command was done.

Departures from the plan

Step 5, an album the library does not have, was not run: it would have emptied the queue under the album the owner had just asked for.

Follow-ups

Step 5, when nothing is being listened to: what iTunes does with an album it does not have, and that the driver logs it.
An account that may publish nowplaying/command for whatever sends play_album by voice, in the tenant’s Terraform.