Deploy and Host PromLens PromQL Explorer on Railway

Build and explain PromQL queries with persistent shared query links.

Draft status: Configuration and upstream documentation reviewed. Container startup, Railway application workflows, restart behavior, backup restoration and costs remain unverified.

About Hosting

Build and explain PromQL queries with persistent shared query links.

Service	Role	Persistent path
`app`	Private application or dependency	`/data`
`promlens`	Public owner gateway	`None`

Why Deploy

Run this application in your own Railway project, with explicit configuration and storage under your control.

Common Use Cases

Build and explain PromQL queries with persistent shared query links.

Dependencies for PromLens PromQL Explorer

Deployment Dependencies

The application images are pinned by registry digest. Database services, when included, stay on the private network. One replica is supported for each volume-backed service.

First use

Open the promlens service's HTTPS domain. Sign in to the owner gateway with username admin and its generated ACCESS_PASSWORD. Complete the application's own setup afterward.

API calls must also send X-Template-Key with that owner password. The gateway forwards native Bearer tokens, strips Basic Authorization, and limits requests to 32 MiB. Browser sessions receive a secure owner cookie. Native clients, webhooks and public sharing require specific compatibility checks before use. Gateway /healthz only checks the proxy, not application readiness.

Sign into the gateway and enter the URL of your Prometheus-compatible server. Build a query and use Share to retain its state in the mounted SQLite database.

Scope and limitations

Prometheus and Grafana are not included. The selected metrics endpoint must be reachable by the browser and allow its origin, or be integrated through your own Grafana configuration.
Shared links remain protected by the owner gateway; they do not grant anonymous access.

Acceptance checks before use

Run up against a test Prometheus endpoint and inspect the query tree.
Create a shared link, restart, and confirm the link still loads.
Confirm generated credentials are distinct on a second fresh deployment.
Back up every listed persistent path and database, then restore into a separate test project.
Measure Railway usage with representative data and workload before estimating operating costs.

Backups and upgrades

Back up databases, file volumes, encryption keys and configuration together. Keep a copy outside the running project. Review upstream migration notes before changing a digest; rollback can require restoring a compatible database and files, not just selecting an older image.

Sources and selection evidence

Upstream documentation: Official prom/promlens image, port 8080 and SQLite link storage flags.
Upstream documentation: Current CLI flags and external URL behavior.
Upstream project

Product and alias searches found no matching public Railway listing during this research. This is a bounded search result; private, unindexed or differently named listings may exist. It is not evidence of demand or revenue.

Upstream software retains its own license and edition restrictions. This deployment draft does not imply upstream endorsement.