Deploy Graylog on GKE - kubernetes

Question

I'm having a hard time deploying Graylog on Google Kubernetes Engine, I'm using this configuration https://github.com/aliasmee/kubernetes-graylog-cluster with some minor modifications. My Graylog server is up but show this error in the interface:
Error message
Request has been terminated
Possible causes: the network is offline, Origin is not allowed by Access-Control-Allow-Origin, the page is being unloaded, etc.
Original Request
GET http://ES_IP:12900/system/sessions
Status code
undefined
Full error message
Error: Request has been terminated
Possible causes: the network is offline, Origin is not allowed by Access-Control-Allow-Origin, the page is being unloaded, etc.
Graylog logs show nothing in particular other than this:
org.graylog.plugins.threatintel.tools.AdapterDisabledException: Spamhaus service is disabled, not starting (E)DROP adapter. To enable it please go to System / Configurations.
at org.graylog.plugins.threatintel.adapters.spamhaus.SpamhausEDROPDataAdapter.doStart(SpamhausEDROPDataAdapter.java:68) ~[?:?]
at org.graylog2.plugin.lookup.LookupDataAdapter.startUp(LookupDataAdapter.java:59) [graylog.jar:?]
at com.google.common.util.concurrent.AbstractIdleService$DelegateService$1.run(AbstractIdleService.java:62) [graylog.jar:?]
at com.google.common.util.concurrent.Callables$4.run(Callables.java:119) [graylog.jar:?]
at java.lang.Thread.run(Thread.java:748) [?:1.8.0_181]
but at the end :
2019-01-16 13:35:00,255 INFO : org.graylog2.bootstrap.ServerBootstrap - Graylog server up and running.
Elastic search health check is green, no issues in ES nor Mongo logs.
I suspect a problem with the connection to Elastic Search though.
curl http://ip_address:9200/_cluster/health\?pretty
{
"cluster_name" : "elasticsearch",
"status" : "green",
"timed_out" : false,
"number_of_nodes" : 1,
"number_of_data_nodes" : 1,
"active_primary_shards" : 4,
"active_shards" : 4,
"relocating_shards" : 0,
"initializing_shards" : 0,
"unassigned_shards" : 0,
"delayed_unassigned_shards" : 0,
"number_of_pending_tasks" : 0,
"number_of_in_flight_fetch" : 0,
"task_max_waiting_in_queue_millis" : 0,
"active_shards_percent_as_number" : 100.0
}

Answer 1

After reading the tutorial you shared, I was able to identify that kubelet needs to run with the argument --allow-privileged.
"Elasticsearch pods need for an init-container to run in privileged mode, so it can set some VM options. For that to happen, the kubelet should be running with args --allow-privileged, otherwise the init-container will fail to run."
It's not possible to customize or modify kubelet parameter/arguments, there is a feature request found here: https://issuetracker.google.com/118428580, so this can be implemented in a future.
Also in case you are modifying kubelet directly on the node(s), it's possible that the master resets the configuration and it isn't guaranteed that the configurations will be persistent.