feat(exporter): implement subprocess execution with active stall watchdog and TCP metrics (#26)

- Replace in-process iperf3 C binding with subprocess execution
- Add active I/O stall detection and connect-timeout
- Expose TCP retransmissions, mean RTT (ms), and exporter cycle timestamp
- Upgrade Dockerfile to Python 3.12 running as non-root user (nobody)
- Fix testTimeout/testDuration environment variable mapping in Helm chart
- Remove dead TrueCharts prometheus-operator chart dependency
- Add unit tests for exporter metric parsing and stall handling
- Switch tooling from devbox to mise

Co-authored-by: Malarbase <malarbase@gmail.com>

charts/iperf3-monitor/Chart.lock

@@ -1,12 +1,9 @@
 dependencies:
 - name: kube-prometheus-stack
   repository: https://prometheus-community.github.io/helm-charts
-  version: 75.7.0
-- name: prometheus-operator
-  repository: oci://tccr.io/truecharts
-  version: 11.5.1
+  version: 91.5.3
 - name: common
   repository: https://bjw-s-labs.github.io/helm-charts/
   version: 4.1.2
-digest: sha256:68485b4e158a6a405073e9c59966d251b62971846cdc9871e41fde46f19aabfe
-generated: "2025-07-01T20:32:00.061995907Z"
+digest: sha256:a3a063101484521564d3e8922c1c1fe7ae8040fe28c2ae246a40d0c00b860e65
+generated: "2026-09-26T09:52:53.951178644+05:30"

charts/iperf3-monitor/Chart.yaml

@@ -21,17 +21,20 @@ maintainers:
 icon: https://raw.githubusercontent.com/malarinv/iperf3-monitor/main/icon.png # Optional icon URL
 annotations:
   artifacthub.io/changes: |
-    - Add initial Helm chart structure.
+    - kind: changed
+      description: Refactor exporter to subprocess with active stall watchdog and connect-timeout
+    - kind: added
+      description: Expose TCP retransmits, mean RTT (ms), and cycle timestamp metrics
+    - kind: changed
+      description: Run exporter container as non-root on Python 3.12
+    - kind: fixed
+      description: Support testDuration, connectTimeoutMs, and stallThresholdSeconds in Helm values
   artifacthub.io/category: networking
 dependencies:
   - name: kube-prometheus-stack # Example dependency if you package the whole stack
     version: ">=30.0.0" # Specify a compatible version range
     repository: https://prometheus-community.github.io/helm-charts
-    condition: "dependencies.install, serviceMonitor.enabled, !dependencies.useTrueChartsPrometheusOperator"
-  - name: prometheus-operator
-    version: ">=8.11.1"
-    repository: "oci://tccr.io/truecharts"
-    condition: "dependencies.install, serviceMonitor.enabled, dependencies.useTrueChartsPrometheusOperator"
+    condition: "dependencies.install, serviceMonitor.enabled"
   - name: common
     version: "4.1.2"
     repository: "https://bjw-s-labs.github.io/helm-charts/"

charts/iperf3-monitor/templates/exporter-controller.yaml

@@ -43,7 +43,11 @@ Proceed with modifications only if the exporter controller is defined.
     {{- $_ := set $baseExporterEnv "LOG_LEVEL" ($exporterControllerConfig.appConfig.logLevel | default "INFO") -}}
     {{- $_ := set $baseExporterEnv "IPERF_SERVER_PORT" ($exporterControllerConfig.appConfig.serverPort | default "5201" | toString) -}}
     {{- $_ := set $baseExporterEnv "IPERF_SERVER_NAMESPACE" (dict "valueFrom" (dict "fieldRef" (dict "fieldPath" "metadata.namespace"))) -}}
-    {{- $_ := set $baseExporterEnv "IPERF_TEST_TIMEOUT" ($exporterControllerConfig.appConfig.testTimeout | default "10" | toString) -}}
+    {{- $testDuration := $exporterControllerConfig.appConfig.testDuration | default $exporterControllerConfig.appConfig.testTimeout | default "5" | toString -}}
+    {{- $_ := set $baseExporterEnv "IPERF_TEST_DURATION" $testDuration -}}
+    {{- $_ := set $baseExporterEnv "IPERF_TEST_TIMEOUT" $testDuration -}}
+    {{- $_ := set $baseExporterEnv "IPERF_CONNECT_TIMEOUT_MS" ($exporterControllerConfig.appConfig.connectTimeoutMs | default "3000" | toString) -}}
+    {{- $_ := set $baseExporterEnv "IPERF_STALL_THRESHOLD_SECONDS" ($exporterControllerConfig.appConfig.stallThresholdSeconds | default "5" | toString) -}}
     {{- $serverLabelSelectorDefault := printf "app.kubernetes.io/name=%s,app.kubernetes.io/instance=%s,app.kubernetes.io/component=server" $appName $release.Name -}}
     {{- $serverLabelSelector := tpl ($exporterControllerConfig.appConfig.serverLabelSelector | default $serverLabelSelectorDefault) . -}}
     {{- $_ := set $baseExporterEnv "IPERF_SERVER_LABEL_SELECTOR" $serverLabelSelector -}}

charts/iperf3-monitor/values.yaml

@@ -27,8 +27,14 @@ controllers:
       testInterval: 300
       # -- Log level for the iperf3 exporter (e.g., DEBUG, INFO, WARNING, ERROR, CRITICAL).
       logLevel: INFO
-      # -- Timeout in seconds for a single iperf3 test run.
-      testTimeout: 10
+      # -- Timeout in seconds for a single iperf3 test run (kept for backward compatibility).
+      testTimeout: 5
+      # -- Duration in seconds for a single iperf3 test run.
+      testDuration: 5
+      # -- Connect timeout in milliseconds for control connection setup.
+      connectTimeoutMs: 3000
+      # -- Stall threshold in seconds (abort test if data transfer halts during test).
+      stallThresholdSeconds: 5
       # -- Protocol to use for testing (tcp or udp).
       testProtocol: tcp
       # -- iperf3 server port to connect to. Should match the server's listening port.
@@ -204,5 +210,3 @@ dependencies:
   # -- Set to false by default. Set to true to install a Prometheus operator dependency (used if serviceMonitor.enabled=true).
   # -- If false (default), and serviceMonitor.enabled is true, you must have a compatible Prometheus Operator already running in your cluster.
   install: false
-  # -- If true, use TrueCharts Prometheus Operator instead of kube-prometheus-stack (used if dependencies.install is true).
-  useTrueChartsPrometheusOperator: false