helm: add envoy gateway addon helm chart support

[shawnh2]

What type of PR is this?

What this PR does / why we need it:

Which issue(s) this PR fixes:

ref #3355

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 68.17%. Comparing base (3712659) to head (0e7436e).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3470      +/-   ##
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+ Coverage   68.12%   68.17%   +0.04%     
==========================================
  Files         165      165              
  Lines       20122    20122              
==========================================
+ Hits        13708    13718      +10     
+ Misses       5416     5409       -7     
+ Partials      998      995       -3     

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[shawnh2]

This PR only include DP metrics and Grafana support, will send another PR to include CP metrics as well (#3474 (comment))

[arkodg]

hey @shawnh2 , @zhaohuabing @guydc and I brought this up in the community meeting today and aligned on

• calling this chart gateway-demo-helm
• adding envoy gateway as a sub chart (sorry for the churn here)

[shawnh2]

This PR only include DP metrics and Grafana support, will send another PR to include CP metrics as well (#3474 (comment))

Lets include Grafana dashboard for CP as well, so wait until #3506 landed.

and the doc under https://gateway.envoyproxy.io/latest/tasks/observability/ can be updated with this helm demo support.

[shawnh2]

hey @shawnh2 , @zhaohuabing @guydc and I brought this up in the community meeting today and aligned on

• calling this chart gateway-demo-helm
• adding envoy gateway as a sub chart (sorry for the churn here)

If we are including envoy-gateway helm as well, we may not install this demo chart just using one helm install, cause eg and prom/grafana should be installed at different namespace. But helm does not support installing dependencies at different namespace. xref: helm/helm#10905

So:

• Do we accpet installing all the dependencies at the same one namespace?
• There's another tool helmfile could solve this problem, but will introduce more operations for users.
• I can understand why we are trying to include eg as a dependency, to provide users with a one-stop eg-with-addons experience. But exclude eg does not affect this, we still can provide one-stop abilities for all the addons. And can solve this problem more easily.

[arkodg]

ah then lets go with the previous approach of gateway-addons-helm and rm envoy-gateway from this chart

[arkodg]

LGTM thanks !

[arkodg]

hey @phlax once this PR merges, we'll be pushing a new Helm Chart envoyproxy/gateway-addons-helm , will the CI be able to push using the existing PAT or do we need to create the repo in dockerhub before hand ?

[zirain]

LGTM, may need wait @phlax first.