Csm Envoy Distroless Telemetry Config Dump

What ephemeral debug containers with kubectl debug are

Cloud Service Mesh sidecars frequently run on distroless container images to reduce attack surfaces and optimize container startup times. Because distroless images omit system utilities such as curl, sh, and bash, operators cannot execute interactive commands directly inside the container using standard kubectl exec workflows. Instead, Kubernetes provides ephemeral debug containers via kubectl debug, which attach a temporary container sharing the target container's process and network namespace.

How it meets the troubleshooting requirement

By executing kubectl debug --image istio/base --target istio-proxy -it -n curl localhost:15000/config_dump, the engineer attaches a container containing essential networking tools (istio/base) directly to the istio-proxy container. This enables querying Envoy's local administration interface on port 15000 to extract the full active configuration dump. The engineer can then inspect the output specifically for the presence and configuration of the Google Cloud Observability filter (stackdriver or Google Cloud metrics filter).

Key advantages and capabilities

• Non-destructive inspection: Inspects live running Envoy proxy configurations without restarting the pod or terminating traffic.
• Zero modification to image footprints: Maintains strict production security postures by keeping core workload and sidecar images minimal and distroless.
• Deep diagnostics: Exposes listener, cluster, route, and filter configurations directly from Envoy's memory table on localhost:15000.
• Identifies control-plane synchronization issues: Verifies whether telemetry configurations pushed by the control plane are accurately parsed and active.

Why this is optimal

This approach directly solves the diagnostic limitation imposed by distroless containers while providing real-time visibility into Envoy's active filters without modifying deployment manifests or breaking security baselines.