`native_metrics_target` was a Jinja filter, so it could not read
DEPLOYMENT_MODE: filters see no Ansible variables. It returned
`<services.<key>.name>:<port>` unconditionally, which is `matrix-synapse:9000`
for matrix. Compose serves that name; swarm does not, because `docker stack
deploy` ignores `container_name` and the alias never exists. This repository
says as much itself, through `lookup('compose_only', 'container_name', ...)`.
The target was therefore scraped and refused, and `playwright.spec.js:274`
reported `web-app-matrix: 1 matching target(s) reporting up != 1`, meaning one
matching target whose `up` value is not 1.
It becomes a lookup that delegates host resolution to `scrape_target`, which
was already mode-aware, so exactly one plugin knows the difference between the
two modes. The port has to be handed over explicitly: matrix exposes metrics on
9000 while `services.synapse.ports.internal.http` is 8008, so the existing
internal-port lookup cannot serve this case on its own.
`scrape_target` now refuses `port` together with an explicit `port_kind`.
Before, `port` won silently and the error text still named the
`ports.internal.<port_kind>` path that the call had never consulted.
`native_metrics_apps` drops an app that pins itself to compose through
`compose_mode_force` while the cluster runs swarm, because the scrape target
would then name the wrong object. Only the literal case: matrix declares that
override as a Jinja expression over its flavour, which this lookup cannot
resolve from the scraping role's variable scope, so variant 0 on swarm stays a
latent mismatch.
The two comment lines claiming `container_name:port` went with the change;
after it they state the opposite of what the code does.
Verified by mutation: with the swarm branch of `scrape_target` disabled, the
new test emits `matrix-synapse:9000`, the exact string CI reported.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
kevinveenbirkenbachandClaude Opus 5
Alejandro Roman