Professional · Node.js / Linux Services / DevOps
UTEST Web App Updater
A shared update service that keeps the UTEST operator web applications current on industrial touch panels.
- Status
- Delivered professional work
- Source
- Private source
- Period
- 2026 — present
- Role
- Designer and developer of the service
- Node.js
- TypeScript
- ARM64 Debian
- Debian packaging
- GitHub Actions
- Software Architecture & System Design
- Full-Stack Software Development
- systemd
- GitHub Releases
- HTTP API
01Interactive exhibit
Stages
Optional / parallel path
Registry · release.json
Detect the application
Finds which operator application is installed, from an explicit setting, from its release file or from its installed package. If several match, it waits for the application to be named.
02
Context & challenge
Industrial touch panels run one of several operator applications, and some applications ship on more than one release track. Keeping every panel on the right version cannot rely on someone updating each device by hand.
The update path also has to be understandable from the application itself: an operator should be able to see whether a newer version exists and how an installation is going.
03
Approach
One small service per device owns the whole update path: application detection, release-track resolution, release discovery, package download, optional verification, installation, status and backup metadata. The operator applications only talk to its HTTP API.
Which applications the service can update is data, not code. A registry lists each application's package name, release source and optional tracks, so adding an application is a registry change.
04
My role
I designed and built the service, its packaging and its CI workflow.
05
What was delivered
Detection and release tracks
Identifies the installed application and resolves which release track it follows, so the right package is considered. A demo launcher can pin the application and track when several are installed.
Release discovery
Reads the release source, skips drafts and prereleases, and selects the highest valid semantic version that has the expected package. A manifest source is supported as well.
Install and status
Downloads the Debian package, verifies it when a digest is available, installs it and reports progress with stable error codes. Transient network failures are retried once.
Backup and restore
Records the version being replaced so the previous release can be installed again on request.
06
Engineering decisions
One owner for the update path
The service owns detection, resolution and installation. The product applications own their own interface, machine APIs and packages.
Applications are data
A registry describes the applications and tracks the service can update, so new applications do not need a new service build.
Designed for the device
It runs as a systemd service on ARM64 Debian, ships as a Debian package and is covered by a package smoke test in CI.
Honest recovery
Restore reinstalls a recorded version. It is not presented as a transactional rollback.
07
Status & outcome
A single update service shared by the UTEST operator applications, with one update path for every release track.
08
Attribution & publication notes
- The service installs software with elevated privileges and is meant to sit behind the device's own web server. Repository is private.
- No claims of zero-downtime updates, atomic installs or guaranteed rollback are made.
Next project
UTEST Web App Launcher