Add eck-apm-server Helm Chart

[naemono]

closes #7489

What is this change?

This adds an ECK APM Server Helm Chart for deploying APM Server instances using the ECK Operator.

Testing

Simple install using basic.yaml and version 8.12.0 works fine:

❯ helm upgrade -i eck-stack . -n elastic --create-namespace -f examples/apm-server/basic.yaml --set eck-elasticsearch.version=8.12.0 --set eck-kibana.version=8.12.0 --set eck-apm-server.version=8.12.0
Release "eck-stack" has been upgraded. Happy Helming!
NAME: eck-stack
LAST DEPLOYED: Tue Feb  6 14:15:34 2024
NAMESPACE: elastic
STATUS: deployed
REVISION: 2
TEST SUITE: None
NOTES:
Elasticsearch ECK-Stack 0.10.0-SNAPSHOT has been deployed successfully!

To see status of all resources, run

kubectl get elastic -n elastic -l "app.kubernetes.io/instance"=eck-stack

More information on the Elastic ECK Operator, and its Helm chart can be found
within our documentation.

https://www.elastic.co/guide/en/cloud-on-k8s/current/index.html

Everything becomes healthy

❯ kubectl get pod -n elastic
NAME                                                   READY   STATUS    RESTARTS   AGE
eck-stack-eck-apm-server-apm-server-6447b96464-ktpmg   1/1     Running   0          65s
elasticsearch-es-default-0                             1/1     Running   0          68s
elasticsearch-es-default-1                             1/1     Running   0          68s
elasticsearch-es-default-2                             1/1     Running   0          68s
kibana-kb-85b4b56ffc-77gng                             1/1     Running   0          65s

All Components are green

❯ kubectl get elastic -n elastic -l "app.kubernetes.io/instance"=eck-stack
NAME                                                    HEALTH   NODES   VERSION   AGE
apmserver.apm.k8s.elastic.co/eck-stack-eck-apm-server   green    1       8.12.0    11m

NAME                                                       HEALTH   NODES   VERSION   PHASE   AGE
elasticsearch.elasticsearch.k8s.elastic.co/elasticsearch   green    3       8.12.0    Ready   11m

NAME                                  HEALTH   NODES   VERSION   AGE
kibana.kibana.k8s.elastic.co/kibana   green    1       8.12.0    11m

Missing ES instance check works:

❯ helm upgrade -i eck-stack . -n elastic --create-namespace -f examples/apm-server/basic.yaml --set eck-elasticsearch.version=8.12.0 --set eck-kibana.version=8.12.0 --set eck-apm-server.version=8.12.0
Error: UPGRADE FAILED: execution error at (eck-stack/charts/eck-apm-server/templates/apmserver.yaml:35:43): A reference to an Elasticsearch instance is required

What isn't working?

• APM+Kibana integration
• APM+Fleet+Kibana testing

Todo

• extended testing
• documentation

[pebrc]

Haven't tested it yet. Just read through the code. Looks good to me just a few small things.

[pebrc]

This is still not mentioned in the APM docs (I know we added it as part of #6063) but I wonder why they don't mention it.

[naemono]

I'll craft something and get our docs updated, since it seems to be required.

[pebrc]

I was more thinking of the docs maintained by the APM team. But an update to our docs would be good too. Can be a separate PR from this one though.

[naemono]

@pebrc Mind double-checking the wording added in 764038d?

I will be added an issue concerning a larger update to the documentation concerning Kibana being a requirement, at least since 8.x.

[naemono]

#7541 created.

[pebrc]

Taking a look now.

[pebrc]

Chart LGTM, only the doc thingy needs to go into another section IMO