ReflowIngressLogs

ReflowIngressLogs is a lightweight Kubernetes utility for dynamically streaming and filtering logs from ingress-nginx-controller pods based on a specific namespace. It connects to your Kubernetes cluster, streams logs, and filters entries containing specific patterns, making it easy to monitor namespace-specific ingress activity.

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Features

• Namespace-Based Filtering: Filters ingress logs for a specific namespace by identifying log entries containing [$NAMESPACE-.
• Dynamic Configuration: Loads configuration from environment variables with support for defaults.
• Kubernetes Integration: Works seamlessly in-cluster or out-of-cluster using KUBECONFIG.
• Robust Logging: Provides structured logs with configurable log levels and formats (JSON or text).
• Graceful Shutdown: Cleans up log streaming on termination signals (SIGINT/SIGTERM).
• Health Monitoring: (Optional) Expose health endpoints for Kubernetes readiness checks.

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Installation

Prerequisites

• Go 1.20+
• A Kubernetes cluster with ingress-nginx-controller deployed.
• Access to Kubernetes API (via KUBECONFIG or in-cluster service account).

Clone the Repository

git clone https://github.com/supporttools/ReflowIngressLogs.git
cd ReflowIngressLogs

Install via Helm

helm repo add supporttools https://charts.support.tools/
helm repo update
helm install reflow-ingress-logs supporttools/reflow-ingress-logs -f values.yaml

To override default values:

helm install reflow-ingress-logs supporttools/reflow-ingress-logs --values custom-values.yaml

To upgrade:

helm upgrade reflow-ingress-logs supporttools/reflow-ingress-logs -f values.yaml

To uninstall:

helm uninstall reflow-ingress-logs

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Configuration

ReflowIngressLogs is configured using environment variables. Below is the list of available options:

Environment Variable	Description	Default
DEBUG	Enables debug logging. (true or false)	false
KUBECONFIG	Path to the Kubernetes config file (used for out-of-cluster).	"" (in-cluster config is used)
NAMESPACE	The namespace to filter logs for.	Required
INGRESS_NAMESPACE	Namespace where ingress-nginx-controller is deployed.	ingress-nginx
LABEL_SELECTOR	Label selector to identify ingress-nginx-controller pods.	app.kubernetes.io/name=ingress-nginx
DEFAULT_LOG_FORMAT	Use the default ingress-nginx log format. (true or false)	true

Custom Log Format

By default, ingress-nginx logs are formatted using the following pattern:

log-format-upstream: '$remote_addr - $remote_user [$time_local] $request $status $body_bytes_sent $http_referer $http_user_agent $request_length $request_time [$proxy_upstream_name] [$proxy_alternative_upstream_name] $upstream_addr $upstream_response_length $upstream_response_time $upstream_status $req_id'

We use the [$NAMESPACE- pattern to filter logs for a specific namespace from the variable $proxy_upstream_name, which is formatted as upstream-<namespace>-<service name>-<service port> in the default configuration. This works well when namespaces do not contain hyphens. However, if you have similar namespace names like example and example-app, log entries from example might inadvertently match example-app due to substring matching.

To avoid this issue, configure a custom log format that explicitly includes the namespace in the log entry:

log-format-upstream: '$remote_addr - $remote_user [$time_local] $request $status $body_bytes_sent $http_referer $http_user_agent $request_length $request_time [$proxy_upstream_name] [namespace: $namespace] [$proxy_alternative_upstream_name] $upstream_addr $upstream_response_length $upstream_response_time $upstream_status $req_id'

Then set DEFAULT_LOG_FORMAT to false in the helm values file:

settings:
  debug: false
  ingressController:
    label: "app.kubernetes.io/name=ingress-nginx"
    namespace: "ingress-nginx"
    defaultLogFormat: false

RKE2 Helm Configuration

For RKE2 deployments, you can configure ingress-nginx logging by applying the following HelmChartConfig:

apiVersion: helm.cattle.io/v1
kind: HelmChartConfig
metadata:
  name: rke2-ingress-nginx
  namespace: kube-system
spec:
  valuesContent: |-
    controller:
      config:
        log-format-upstream: '$remote_addr - $remote_user [$time_local] $request $status $body_bytes_sent $http_referer $http_user_agent $request_length $request_time [$proxy_upstream_name] [namespace: $namespace] [$proxy_alternative_upstream_name] $upstream_addr $upstream_response_length $upstream_response_time $upstream_status $req_id'

Then use the following values in the ReflowIngressLogs helm chart:

settings:
  debug: false
  ingressController:
    label: "app.kubernetes.io/name=rke2-ingress-nginx"
    namespace: "kube-system"
    defaultLogFormat: false

Example Configuration

export DEBUG=true
export KUBECONFIG=/path/to/kubeconfig
export NAMESPACE=app
export INGRESS_NAMESPACE=ingress-nginx
export LABEL_SELECTOR=app.kubernetes.io/name=ingress-nginx

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