PMM-15362 Disable default-on node_exporter collectors

[theTibi]

Feature Build for PMM-15362 — --disable-collectors had no effect for node_exporter collectors that node_exporter enables by default.

Builds PMM Server and Client from the fix branch so the change can be tested as an image. The fix is server-side (pmm-managed generates the exporter command line) plus a one-line pmm-admin change, so only the pmm monorepo is pinned.

Component PRs

• percona/pmm — PMM-15362 Disable default-on node_exporter collectors percona/pmm#5839

ci.yml

deps:
  - name: pmm
    branch: PMM-15362-disable-default-node-collectors
    url: https://github.com/percona/pmm

What to check on the built image

1. Register a client, then: pmm-admin inventory change agent node-exporter <agent_id> --disable-collectors=diskstats
2. The exporter command line should now carry --no-collector.diskstats (before the fix, the --collector.diskstats enable flag was merely removed, which is a no-op for a default-on collector).
3. curl -s http://pmm:<agent_id>@127.0.0.1:<port>/metrics | grep -c '^node_disk_' → 0 (was 324).
4. --disable-collectors=cpu,cpu must not stop node_exporter from starting — a repeated flag is rejected by its flag parser, so the server de-duplicates.
5. --disable-collectors="cpu, meminfo" (with a space) must disable both — the change agent path now trims, as add already did.
6. Control: --disable-collectors=processes (a non-default collector) must keep working and must not gain a --no-collector.processes flag.

Full evidence, including a live before/after on an isolated PMM 3.10.0 server, is in the component PR's test plan.

🤖 Generated with Claude Code

[JNKPercona]

Server docker: perconalab/pmm-server-fb:PR-4547-6c80a3e
Client docker: perconalab/pmm-client-fb:PR-4547-6c80a3e
Client tarball: https://s3.us-east-2.amazonaws.com/pmm-build-cache/PR-BUILDS/pmm-client/pmm-client-PR-4547-6c80a3e.tar.gz
Staging instance: https://pmm.cd.percona.com/job/pmm3-aws-staging-start/parambuild/?DOCKER_VERSION=perconalab/pmm-server-fb:PR-4547-6c80a3e&CLIENT_VERSION=https://s3.us-east-2.amazonaws.com/pmm-build-cache/PR-BUILDS/pmm-client/pmm-client-PR-4547-6c80a3e.tar.gz

[JNKPercona]

API tests have succeded: https://pmm.cd.percona.com/job/pmm3-api-tests/7174/