passenger-go-exporter

README

Passenger Go Exporter

Passenger status monitoring agent for Prometheus.

You can be used as a sidecar container for Passenger applications. Implemented in golang, keeps memory consumption below 100MB, and runs on CPU 0.05 core.

Supported version

• golang: 1.23
• Passenger: 6.0.23, or later.

All other versions have not been tested.

How to use

We expect to using this as a sidecar.
A example is in here.

Sidecar Pattern

Container images can be pulled from ghcr.io/rakutentech/passenger-go-exporter.
Passsenger Go Exporter must be shared the directory specified by PASSENGER_INSTANCE_REGISTRY_DIR with passenger application.

Passenger Application side defines PASSENGER_INSTANCE_REGISTRY_DIR environment varibles, and specify emptyDir volume. Passenger Go Exporter side defines similarly.

    spec:
      volumes:
        - name: tmp
          emptyDir: {}
      containers:
        - name: example
          env:
            - name: PASSENGER_INSTANCE_REGISTRY_DIR
              value: /tmp/ruby
          volumeMounts:
            - mountPath: /tmp/ruby
              name: tmp
        - name: passenger-exporter
          image: ghcr.io/rakutentech/passenger-go-exporter:v1.4.4
          imagePullPolicy: IfNotPresent
          env:
            - name: PASSENGER_INSTANCE_REGISTRY_DIR
              value: /tmp/ruby
          volumeMounts:
            - mountPath: /tmp/ruby
              name: tmp

Passenger Go Exporter works with the following resources definitions.

          resources:
            limits:
              cpu: 20m
              memory: 60Mi
            requests:
              cpu: 20m
              memory: 60Mi

Health check of Passenger Go Exporter is following contents.

          livenessProbe:
            initialDelaySeconds: 10
            timeoutSeconds: 2
            httpGet:
              path: /health
              port: 9768
          readinessProbe:
            timeoutSeconds: 1
            httpGet:
              path: /health
              port: 9768

Default of Port number is 9768. But this could be changed by args defined.

          - args:
            - "-port"
            - "9149"

Running Options

Name	Description	Default
-port	Listening port number	9768

Collect Metrics

Name	Labels	Description
passenger_go_wait_list_size	name	number of requests in queue in each application
passenger_go_process_count	name	number of current application processes in each application
passenger_go_process_real_memory_bytes	name, pid	memory usage of process in each PID
passenger_go_process_processed	name, pid	the number of requests handled by each process

Documentation

Overview

Contained Prometheus Component for monitoring Passenger application.

If you want to know the metrics or so on, ,Please refer to the README.