Make K8s metrics API optional

[shtanos]

Describe the feature you would like to see

Add an option to fully disable metrics-related functionality in Dozzle for Kubernetes clusters where Metrics Server is not installed or required.

Description:
Currently, Dozzle tries to access Kubernetes metrics by default even when Metrics Server is not present. This causes unnecessary errors and forces users to grant extra permissions.

Describe how you would like to see this feature implemented

The current behavior forces users to:

Install Metrics Server even if metrics are not needed.
Add RBAC permissions for metrics.k8s.io or nodes.
Deal with startup errors related to missing metrics.

Proposed Solution:
Add a new environment variable like DOZZLE_DISABLE_METRICS=true to completely skip metrics-related code, including:

No attempts to connect to metrics.k8s.io.
No background checks for metrics.
No need for metrics-related RBAC rules.
Example Configuration:
env:

• name: DOZZLE_MODE
  value: "k8s"
• name: DOZZLE_METRICS
  value: "false"

Describe any alternatives you've considered

No response

[amir20]

Currently, even when DOZZLE_METRICS=false is set, Dozzle attempts to query the Kubernetes Metrics API (metrics.k8s.io/pods). This results in errors like:

Sorry where is DOZZLE_METRICS=false documented that you would expect it to disable metrics?

Disabling metrics is a pretty big change to Dozzle. It would require complex changes to multiple components that I won't have time to do. You are the first person to ask for this feature though. If a lot of k8s users need this feature then perhaps I or someone can work on it.

[shtanos]

Currently, even when DOZZLE_METRICS=false is set, Dozzle attempts to query the Kubernetes Metrics API (metrics.k8s.io/pods). This results in errors like:

Sorry where is DOZZLE_METRICS=false documented that you would expect it to disable metrics?

Disabling metrics is a pretty big change to Dozzle. It would require complex changes to multiple components that I won't have time to do. You are the first person to ask for this feature though. If a lot of k8s users need this feature then perhaps I or someone can work on it.

You’re absolutely right — I made a mistake assuming DOZZLE_METRICS=false already exists. My intention was to suggest adding a new option (e.g., DOZZLE_DISABLE_METRICS=true) to make metrics integration optional. This would help users in clusters where Metrics Server is not installed (e.g., minimal setups), avoiding:

Forced dependencies on metrics.k8s.io.
Unnecessary RBAC permissions.
Startup errors like panic: failed to get pod metrics.
This change would simplify deployments for users who only need log viewing. No need for complex changes unless there’s broader demand. Thanks for maintaining Dozzle — it’s a great tool!
ps I've updated the issue accordingly. Thanks for the clarification!

[amir20]

Great. Currently, the documentation states that metrics is required. However, if more people use Kubernetes, I will revisit this issue to broaden the support.

[amir20]

I haven't seen many other people request this. I am going to change the title and move to discussion.

[db757]

In my case I'm trying to run on a production EKS cluster (AWS) where I don't have permissions to the metrics server (even though it does exist), and get a panic.

{"level":"panic","version":"v10.5.3","error":"pods.metrics.k8s.io is forbidden: User \"<REDACTED>\" cannot list resource \"pods\" in API group \"metrics.k8s.io\" at the cluster scope","time":"2026-05-17T14:47:11Z","message":"failed to get pod metrics"}
panic: failed to get pod metrics

goroutine 154 [running]:
github.com/rs/zerolog/log.Panic.(*Logger).Panic.func1({0x204aeb0?, 0x0?})
	/go/pkg/mod/github.com/rs/zerolog@v1.35.1/log.go:411 +0x30
github.com/rs/zerolog.(*Event).msg(0x46fa8af8e460, {0x204aeb0, 0x19})
	/go/pkg/mod/github.com/rs/zerolog@v1.35.1/event.go:167 +0x244
github.com/rs/zerolog.(*Event).Msg(...)
	/go/pkg/mod/github.com/rs/zerolog@v1.35.1/event.go:119
github.com/amir20/dozzle/internal/k8s.(*K8sStatsCollector).Start.func1({0x0?, 0x0?}, 0x0?)
	/dozzle/internal/k8s/stats_collector.go:103 +0xc0
github.com/samber/lo/parallel.ForEach[...].func1(0x0?)
	/go/pkg/mod/github.com/samber/lo@v1.53.0/parallel/slice.go:38 +0x2c
created by github.com/samber/lo/parallel.ForEach[...] in goroutine 89
	/go/pkg/mod/github.com/samber/lo@v1.53.0/parallel/slice.go:37 +0x64

In my case even downgrading this to an error log instead of a panic will be good enough.