[Nginx Ingress Controller Logs] added missing filestream fingerprint settings

[BBQigniter]

Proposed commit message

This commit should fix a problem we detected using this integration. It seems to stop scraping nginx-ingress-controller logs from Kubernetes clusters with elastic-agents installed. Unfortunately I do not have a lot of knowledge about creating/maintaining integrations and currently have no option to test this change somehow, but by comparing the Kubernetes integration package files with this integration I think I figured out what's missing so that the agent's Filebeat detects container-log rotations correctly and continues to scrape the needed logs.

I think only the fingerprint settings similarly like in the Kubernetes integration are missing in the access- and error-log files - like in

https://github.com/elastic/integrations/blob/main/packages/kubernetes/data_stream/container_logs/manifest.yml#L90-L106
and
https://github.com/elastic/integrations/blob/main/packages/kubernetes/data_stream/container_logs/agent/stream/stream.yml.hbs#L20-L26

Checklist

• I have reviewed tips for building integrations and this pull request is aligned with them.
• I have verified that all data streams collect metrics or logs.
• I have added an entry to my package's changelog.yml file.
• I have verified that Kibana version constraints are current according to guidelines.
• I have verified that any added dashboard complies with Kibana's Dashboard good practices

[gizas]

I have tested the build locally and all work fine.

Way to test is:

Prerequisites to have a k8s cluster running and also install the elastic-package

1. Clone the specific branch/pr
2. Navigate to the folder of this Pr under integrations/integrations/packages/nginx_ingress_controller
3. Run elastic-package build

elastic-package build
Build the package
2026/01/12 13:51:56  INFO License text found in "/Users/andreasgkizas/integrations/integrations/LICENSE.txt" will be included in package
README.md file rendered: /Users/andreasgkizas/integrations/integrations/packages/nginx_ingress_controller/docs/README.md
Package built: /Users/andreasgkizas/integrations/integrations/build/packages/nginx_ingress_controller-1.14.0.zip
Done

5. Then deploy the elastic stack locally by running elastic-package stack up -d -v --version=9.2.1
6. Install Elastic-Agent locally with the Nginx-integration configured

See below the relevant text-boxes that appear in version 1.14.0 of the integration

FYI there is an warning that appears by default in the logs

{"log.level":"warn","@timestamp":"2026-01-12T10:49:27.159Z","message":"1 file is too small to be ingested, files need to be at least 1024 in size for ingestion to start. To change this behaviour set 'prospector.scanner.fingerprint.length' and 'prospector.scanner.fingerprint.offset'. Enable debug logging to see all file names.","component":{"binary":"filebeat","dataset":"elastic_agent.filebeat","id":"filestream-default","type":"filestream"},"log":{"source":"filestream-default"},"ecs.version":"1.6.0","log.logger":"input.scanner","log.origin":{"file.line":423,"file.name":"filestream/fswatch.go","function":"github.com/elastic/beats/v7/filebeat/input/filestream.(*fileScanner).GetFiles"},"service.name":"filebeat","filestream_id":"nginx-ingress-controller-access-7a902c467ad8c61e88a0f9dc70af800e3c3cb2b3b9d9d31b2c41b102f527bc8a","ecs.version":"1.6.0"}

You need to update example prospector.scanner.fingerprint.length: 70 in the box that appears above.

[gizas]

LGTM

[gizas]

@andrewkroh have u seen this behaviour again regarding buildkite/integrations ci step?
I can not find this run in buildkite, seems paused and this PR never gets ready to be merged.

Does it have sth to do with the fork and/or with the note above: This branch has not been deployed ? Any help really appreciated