Filtering by tags

The GCE discovery can also filter machines to include in the cluster based on tags using discovery.gce.tags settings. For example, setting discovery.gce.tags to dev will only filter instances having a tag set to dev. Several tags set will require all of those tags to be set for the instance to be included.

One practical use for tag filtering is when a GCE cluster contains many nodes that are not master-eligible Elasticsearch nodes. In this case, tagging the GCE instances that are running the master-eligible Elasticsearch nodes, and then filtering by that tag, will help discovery to run more efficiently.

Add your tag when building the new instance:

gcloud compute instances create myesnode1 --project=es-cloud \
       --scopes=compute-rw \
       --tags=elasticsearch,dev

Then, define it in elasticsearch.yml:

cloud:
  gce:
      project_id: es-cloud
      zone: europe-west1-a
discovery:
      seed_providers: gce
      gce:
            tags: elasticsearch, dev