当 运行 作为 k8s 集群中的作业时,Chaostoolkit 实验失败

Chaostoolkit experiment failing when run as a Job from within a k8s cluster

我正在使用 chaostoolkit 并且能够从命令行成功 运行 混沌实验。但是,当我尝试 运行 与 k8s 中的作业相同时,它会抛出 'connection refused' 错误。我觉得奇怪的是,有时稳态假设步骤 运行s 成功并且 returns 200 OK 而在终止 pod 操作失败时,但很多时候它也在假设步骤中失败本身(在终止 pod 的操作之前)。顺便说一下,我在 Google 云中执行此操作。

在某些 运行 期间,我看到操作前的假设以及终止 pod 都是成功的,但是操作后的假设(终止)得到 'connection refused' 错误。

任何 help/tip 不胜感激。

这是错误消息:

[2022-02-03 07:24:54 DEBUG] [caching:35] Cached 2 activities
[2022-02-03 07:24:54 INFO] [experiment:54] Validating the experiment's syntax
[2022-02-03 07:24:54 DEBUG] [configuration:47] Loading configuration...
[2022-02-03 07:24:54 DEBUG] [secret:74] Loading secrets...
[2022-02-03 07:24:54 DEBUG] [secret:89] Secrets loaded
[2022-02-03 07:25:12 INFO] [experiment:103] Experiment looks valid
[2022-02-03 07:25:12 DEBUG] [caching:42] Clearing activities cache
[2022-02-03 07:25:12 DEBUG] [caching:25] Building activity cache...
[2022-02-03 07:25:12 DEBUG] [caching:35] Cached 2 activities
[2022-02-03 07:25:12 INFO] [experiment:182] Running experiment: What happens if we terminate an instance of the application?
[2022-02-03 07:25:12 DEBUG] [configuration:47] Loading configuration...
[2022-02-03 07:25:12 DEBUG] [secret:74] Loading secrets...
[2022-02-03 07:25:12 DEBUG] [secret:89] Secrets loaded
[2022-02-03 07:25:12 DEBUG] [__init__:39] Initializing controls
[2022-02-03 07:25:12 DEBUG] [__init__:355] No controls to apply on 'experiment'
[2022-02-03 07:25:12 INFO] [hypothesis:184] Steady state hypothesis: The app is healthy
[2022-02-03 07:25:12 DEBUG] [__init__:355] No controls to apply on 'hypothesis'
[2022-02-03 07:25:12 DEBUG] [__init__:355] No controls to apply on 'activity'
[2022-02-03 07:25:12 INFO] [activity:160] Probe: app-responds-to-requests
[2022-02-03 07:25:12 DEBUG] [activity:233] Activity failed
    Traceback (most recent call last):
      File "/usr/local/lib/python3.8/site-packages/urllib3/connection.py", line 156, in _new_conn
        conn = connection.create_connection(
      File "/usr/local/lib/python3.8/site-packages/urllib3/util/connection.py", line 84, in create_connection
        raise err
      File "/usr/local/lib/python3.8/site-packages/urllib3/util/connection.py", line 74, in create_connection
        sock.connect(sa)
    ConnectionRefusedError: [Errno 111] Connection refused

这是我提供给作业的配置:

health-http.yaml: |
    version: 1.0.0
    title: What happens if we terminate an instance of the application?
    description: If an instance of the application is terminated, the applications as a whole should still be operational.
    tags:
    - k8s
    - pod
    steady-state-hypothesis:
      title: The app is healthy
      probes:
      - name: app-responds-to-requests
        type: probe
        tolerance: 200
        provider:
          type: http
          timeout: 10
          verify_tls: false
          url: http://newapp
          headers:
            Host: newapp.example.com
    method:
    - type: action
      name: terminate-app-pod
      provider:
        type: python
        module: chaosk8s.pod.actions
        func: terminate_pods
        arguments:
          label_selector: app=newapp
          rand: true
          ns: default
      pauses: 
        after: 2

我能够通过 ssh 进入一个虚拟的 nginx pod 并且 'curl newapp' 并且它 returns 正确响应,所以该服务肯定是活跃的并且正在工作。我创建的服务帐户除其他权限外还具有获取、列出、删除 pods 的权限。

这是实验清单:

apiVersion: batch/v1
kind: Job
metadata:
  name: newapp-chaos
spec:
  activeDeadlineSeconds: 600
  backoffLimit: 0
  template:
    metadata:
      labels:
        app: newapp
      annotations:
        sidecar.istio.io/inject: "false"
    spec:
      serviceAccountName: newapp-chaos
      restartPolicy: Never
      containers:
      - name: chaostoolkit
        image: vfarcic/chaostoolkit:1.4.1-2
        args:
        - --verbose
        - run
        - /experiment/health-http.yaml
        env:
        - name: CHAOSTOOLKIT_IN_POD
          value: "true"
        volumeMounts:
        - name: config
          mountPath: /experiment
          readOnly: true
        resources:
          limits:
            cpu: 20m
            memory: 64Mi
          requests:
            cpu: 20m
            memory: 64Mi
      volumes:
      - name: config
        configMap:
          name: newapp-config

这是我的应用清单:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: newapp-v2
spec:
  replicas: 1
  selector:
    matchLabels:
      app: newapp
  strategy:
    rollingUpdate:
      maxSurge: 1
      maxUnavailable: 1
    type: RollingUpdate
  template:
    metadata:
      labels:
        app: newapp
        version: v2
    spec:
      containers:
      - image: rstarmer/hostname:v2
        imagePullPolicy: Always
        name: newapp
      restartPolicy: Always
---
apiVersion: v1
kind: Service
metadata:
  labels:
    app: newapp
  name: newapp
spec:
  #externalTrafficPolicy: Cluster
  ports:
  - port: 80
    protocol: TCP
    targetPort: 80
  selector:
    app: newapp
  sessionAffinity: None

这里是终止也很好但后来遇到错误的输出:

[2022-02-03 09:43:22 INFO] [hypothesis:184] Steady state hypothesis: The app is healthy
[2022-02-03 09:43:22 DEBUG] [__init__:355] No controls to apply on 'hypothesis'
[2022-02-03 09:43:22 DEBUG] [__init__:355] No controls to apply on 'activity'
[2022-02-03 09:43:22 INFO] [activity:160] Probe: app-responds-to-requests
[2022-02-03 09:43:22 DEBUG] [activity:179]   => succeeded with '{'status': 200, 'headers': {'Server': 'nginx/1.15.4', 'Date': 'Thu, 03 Feb 2022 09:43:22 GMT', 'Content-Type': 'text/html', 'Content-Length': '208', 'Last-Modified': 'Thu, 03 Feb 2022 07:21:47 GMT', 'Connection': 'keep-alive', 'ETag': '"61fb828b-d0"', 'Accept-Ranges': 'bytes'}, 'body': "<HTML>\n<HEAD>\n<TITLE>This page is on newapp-v2-866f8798cd-8s424 and is version v2</TITLE>\n</HEAD><BODY>\n<H1>THIS IS HOST newapp-v2-866f8798cd-8s424</H1>\n<H2>And we're running version: v2</H2>\n</BODY>\n</HTML>\n"}'
[2022-02-03 09:43:22 DEBUG] [__init__:355] No controls to apply on 'activity'
[2022-02-03 09:43:22 DEBUG] [hypothesis:212] allowed tolerance is 200
[2022-02-03 09:43:22 INFO] [hypothesis:222] Steady state hypothesis is met!
[2022-02-03 09:43:22 DEBUG] [__init__:355] No controls to apply on 'hypothesis'
[2022-02-03 09:43:22 DEBUG] [__init__:355] No controls to apply on 'method'
[2022-02-03 09:43:22 DEBUG] [__init__:355] No controls to apply on 'activity'
[2022-02-03 09:43:22 INFO] [activity:160] Action: terminate-app-pod
[2022-02-03 09:43:22 DEBUG] [python:34] Activity 'terminate-app-pod' loaded from '/usr/local/lib/python3.8/site-packages/chaosk8s/pod/actions.py'
[2022-02-03 09:43:23 DEBUG] [actions:193] Found 3 pods labelled 'app=newapp' in ns default
[2022-02-03 09:43:23 DEBUG] [activity:181]   => succeeded without any result value
[2022-02-03 09:43:23 INFO] [activity:197] Pausing after activity for 2s...
[2022-02-03 09:43:25 DEBUG] [__init__:355] No controls to apply on 'activity'
[2022-02-03 09:43:25 DEBUG] [__init__:355] No controls to apply on 'method'
[2022-02-03 09:43:25 INFO] [hypothesis:184] Steady state hypothesis: The app is healthy
[2022-02-03 09:43:25 DEBUG] [__init__:355] No controls to apply on 'hypothesis'
[2022-02-03 09:43:25 DEBUG] [__init__:355] No controls to apply on 'activity'
[2022-02-03 09:43:25 INFO] [activity:160] Probe: app-responds-to-requests
[2022-02-03 09:43:25 DEBUG] [activity:233] Activity failed
    Traceback (most recent call last):
      File "/usr/local/lib/python3.8/site-packages/urllib3/connection.py", line 156, in _new_conn
        conn = connection.create_connection(
      File "/usr/local/lib/python3.8/site-packages/urllib3/util/connection.py", line 84, in create_connection
        raise err
      File "/usr/local/lib/python3.8/site-packages/urllib3/util/connection.py", line 74, in create_connection
        sock.connect(sa)
    ConnectionRefusedError: [Errno 111] Connection refused

在折腾了一天多之后,我尝试重新安装 Istio,它开始运行良好。那一定是 Istio 出了问题。