Server-side apply - Levelrail

Server-side apply lets several tools (CI, an operator, the dashboard, a person running edit) each own part of one resource without overwriting each other. Each sends only the fields it cares about. The server merges them, remembers who set which field, and refuses a change to a field someone else owns. Supported kinds: apps and databases. Other kinds answer 405. Stack resources keep changing through their stack apply, and an app or database a stack owns is refused with 409.

API

PATCH /api/v2/apps/{name}?fieldManager=ci
PATCH /api/v2/databases/{name}?fieldManager=ci
Content-Type: application/apply-patch+yaml   (or application/apply-patch+json, application/json)

The body is a partial resource document in the same shape export writes:

kind: App
metadata:
  name: web
  resourceVersion: "42"   # optional precondition
spec:
  service:
    port: 8080

Query parameters:

Parameter	Meaning
`fieldManager`	Required. Who owns the fields this request sends.
`force=true`	Take over fields another manager owns instead of failing.
`dryRun=All`	Merge, validate and plan, but write nothing. The response holds the merged spec and the plan.
`resourceVersion`	Precondition, same as `metadata.resourceVersion`: the request fails with `409` unless the object is still at this version.

The route uses the same per-object authorization as the v1 write routes (write ability plus any IAM policy on app:NAME or database:NAME).

Merge rules

Fields are tracked at leaf level, as JSON pointers such as /spec/service/port. Lists are one field.
A field sent with the same value another manager set is shared by both.
A field sent with a different value than another manager set is a conflict. The 409 body lists each path and manager. Pass force=true to take it over.
A field a manager set before and no longer sends is removed, unless another manager still owns it.
A field sent as null is removed.
Env values you cannot read are kept as they are when you do not send them.

Ownership is returned in metadata.managedFields by the PATCH response and by GET /api/v2/{kind}/{name}. Applied changes appear on the watch stream as MODIFIED events.

CLI

levelrail-cli apply -f web.yaml --server-side [--field-manager NAME] [--force-conflicts] [--dry-run=server]

The field manager defaults to the command name. edit app NAME uses server-side apply too: it sends only the fields you changed, forces ownership of them, and carries the version you opened as a precondition, so a concurrent change makes the save fail instead of being overwritten.

Limits

One server-side apply runs at a time per control plane, so the version check and the write happen together. A write through a v1 route in between can still land; the precondition catches it on the next apply.
Database applies read the full export to find the database, which is slower on large installs.

​API

​Merge rules

​CLI

​Limits

API

Merge rules

CLI

Limits