尝试在 Raspberry Pi 3B+ 上运行 OpenFaas 函数时出现 ImageInspectError

Question

我正在尝试使用OpenFaas project 和在 2 Raspberry Pi 3B+ 上运行的 kubernetes 集群部署一个函数。 不幸的是，应该处理该函数的 pod 将进入ImageInspectError 状态... 我尝试直接使用 Docker 运行该函数，该函数包含在 Docker 映像中，一切正常。

我在 OpenFaas github 上开了一个issue，维护人员告诉我直接向 Kubernetes 社区询问一些线索。

我的第一个问题是：ImageInspectError 是什么意思，它来自哪里？

这是我掌握的所有信息：

预期行为

Pod 应该运行。

当前行为

NAMESPACE     NAME                                 READY     STATUS              RESTARTS   AGE
kube-system   etcd-masternode                      1/1       Running             1          1d
kube-system   kube-apiserver-masternode            1/1       Running             1          1d
kube-system   kube-controller-manager-masternode   1/1       Running             1          1d
kube-system   kube-dns-7f9b64f644-x42sr            3/3       Running             3          1d
kube-system   kube-proxy-wrp6f                     1/1       Running             1          1d
kube-system   kube-proxy-x6pvq                     1/1       Running             1          1d
kube-system   kube-scheduler-masternode            1/1       Running             1          1d
kube-system   weave-net-4995q                      2/2       Running             3          1d
kube-system   weave-net-5g7pd                      2/2       Running             3          1d
openfaas-fn   figlet-7f556fcd87-wrtf4              1/1       Running             0          4h
openfaas-fn   testfaceraspi-7f6fcb5897-rs4cq       0/1       ImageInspectError   0          2h
openfaas      alertmanager-66b98dd4d4-kcsq4        1/1       Running             1          1d
openfaas      faas-netesd-5b5d6d5648-mqftl         1/1       Running             1          1d
openfaas      gateway-846f8b5686-724q8             1/1       Running             2          1d
openfaas      nats-86955fb749-7vsbm                1/1       Running             1          1d
openfaas      prometheus-6ffc57bb8f-fpk6r          1/1       Running             1          1d
openfaas      queue-worker-567bcf4d47-ngsgv        1/1       Running             2          1d

testfaceraspi 没有运行。

来自 pod 的日志：

$ kubectl logs testfaceraspi-7f6fcb5897-rs4cq -n openfaas-fn
Error from server (BadRequest): container "testfaceraspi" in pod "testfaceraspi-7f6fcb5897-rs4cq" is waiting to start: ImageInspectError

Pod 描述：

$ kubectl describe pod -n openfaas-fn  testfaceraspi-7f6fcb5897-rs4cq 
Name:           testfaceraspi-7f6fcb5897-rs4cq
Namespace:      openfaas-fn
Node:           workernode/10.192.79.198
Start Time:     Thu, 12 Jul 2018 11:39:05 +0200
Labels:         faas_function=testfaceraspi
                pod-template-hash=3929761453
Annotations:    prometheus.io.scrape=false
Status:         Pending
IP:             10.40.0.16
Controlled By:  ReplicaSet/testfaceraspi-7f6fcb5897
Containers:
  testfaceraspi:
    Container ID:   
    Image:          gallouche/testfaceraspi
    Image ID:       
    Port:           8080/TCP
    Host Port:      0/TCP
    State:          Waiting
      Reason:       ImageInspectError
    Ready:          False
    Restart Count:  0
    Liveness:       exec [cat /tmp/.lock] delay=3s timeout=1s period=10s #success=1 #failure=3
    Readiness:      exec [cat /tmp/.lock] delay=3s timeout=1s period=10s #success=1 #failure=3
    Environment:
      fprocess:  python3 index.py
    Mounts:
      /var/run/secrets/kubernetes.io/serviceaccount from default-token-5qhnn (ro)
Conditions:
  Type           Status
  Initialized    True 
  Ready          False 
  PodScheduled   True 
Volumes:
  default-token-5qhnn:
    Type:        Secret (a volume populated by a Secret)
    SecretName:  default-token-5qhnn
    Optional:    false
QoS Class:       BestEffort
Node-Selectors:  <none>
Tolerations:     node.kubernetes.io/not-ready:NoExecute for 300s
                 node.kubernetes.io/unreachable:NoExecute for 300s
Events:
  Type     Reason            Age                 From                 Message
  ----     ------            ----                ----                 -------
  Warning  DNSConfigForming  2m (x1019 over 3h)  kubelet, workernode  Search Line limits were exceeded, some search paths have been omitted, the applied search line is: openfaas-fn.svc.cluster.local svc.cluster.local cluster.local heig-vd.ch einet.ad.eivd.ch web.ad.eivd.ch

还有事件日志：

$ kubectl get events --sort-by=.metadata.creationTimestamp -n openfaas-fn
LAST SEEN   FIRST SEEN   COUNT     NAME                                              KIND         SUBOBJECT                        TYPE      REASON                  SOURCE                  MESSAGE
14m         1h           347       testfaceraspi-7f6fcb5897-rs4cq.1540db41e89d4c52   Pod                                           Warning   DNSConfigForming        kubelet, workernode     Search Line limits were exceeded, some search paths have been omitted, the applied search line is: openfaas-fn.svc.cluster.local svc.cluster.local cluster.local heig-vd.ch einet.ad.eivd.ch web.ad.eivd.ch
4m          1h           75        figlet-7f556fcd87-wrtf4.1540db421002b49e          Pod                                           Warning   DNSConfigForming        kubelet, workernode     Search Line limits were exceeded, some search paths have been omitted, the applied search line is: openfaas-fn.svc.cluster.local svc.cluster.local cluster.local heig-vd.ch einet.ad.eivd.ch web.ad.eivd.ch
10m         10m          1         testfaceraspi-7f6fcb5897-d6z78.1540df9ed8b91865   Pod                                           Normal    Scheduled               default-scheduler       Successfully assigned testfaceraspi-7f6fcb5897-d6z78 to workernode
10m         10m          1         testfaceraspi-7f6fcb5897.1540df9ed6eee11f         ReplicaSet                                    Normal    SuccessfulCreate        replicaset-controller   Created pod: testfaceraspi-7f6fcb5897-d6z78
10m         10m          1         testfaceraspi-7f6fcb5897-d6z78.1540df9eef3ef504   Pod                                           Normal    SuccessfulMountVolume   kubelet, workernode     MountVolume.SetUp succeeded for volume "default-token-5qhnn" 
4m          10m          27        testfaceraspi-7f6fcb5897-d6z78.1540df9eef5445c0   Pod                                           Warning   DNSConfigForming        kubelet, workernode     Search Line limits were exceeded, some search paths have been omitted, the applied search line is: openfaas-fn.svc.cluster.local svc.cluster.local cluster.local heig-vd.ch einet.ad.eivd.ch web.ad.eivd.ch
8m          9m           8         testfaceraspi-7f6fcb5897-d6z78.1540df9f670d0dad   Pod          spec.containers{testfaceraspi}   Warning   InspectFailed           kubelet, workernode     Failed to inspect image "gallouche/testfaceraspi": rpc error: code = Unknown desc = Error response from daemon: readlink /var/lib/docker/overlay2/l: invalid argument
9m          9m           7         testfaceraspi-7f6fcb5897-d6z78.1540df9f670fcf3e   Pod          spec.containers{testfaceraspi}   Warning   Failed                  kubelet, workernode     Error: ImageInspectError

重现步骤（针对错误）

1. 在 2 节点 k8s 集群上部署 OpenFaas
2. 使用faas new testfaceraspi --lang python3-armhf 创建函数

3. 在handler.py中添加如下代码：

   import json
   def handle(req):
       jsonl = json.loads(req)
   
       return ("Found " + str(jsonl["nbFaces"]) + " faces in OpenFaas Function on raspi !")
   

4. 更改.yml中的网关和图像 提供者： 名称：faas 网关：http://127.0.0.1:31112

   functions:
     testfaceraspi:
       lang: python3-armhf
       handler: ./testfaceraspi
       image: gallouche/testfaceraspi
   

5. 运行faas build -f testfacepi.yml

6. 使用docker login登录DockerHub
7. 运行faas push -f testfacepi.yml
8. 运行faas deploy -f testfacepi.yml

您的环境

• FaaS-CLI 版本（完整输出来自：faas-cli version）：

  Commit: 3995a8197f1df1ecdf524844477cffa04e4690ea
  Version: 0.6.11
  

• Docker 版本（完整输出来自：docker version）：

  Client:
   Version:       18.04.0-ce
   API version:   1.37
   Go version:    go1.9.4
   Git commit:    3d479c0
   Built: Tue Apr 10 18:25:24 2018
   OS/Arch:       linux/arm
   Experimental:  false
   Orchestrator:  swarm
  
   Server:
   Engine:
    Version:      18.04.0-ce
    API version:  1.37 (minimum version 1.12)
    Go version:   go1.9.4
    Git commit:   3d479c0
    Built:        Tue Apr 10 18:21:25 2018
    OS/Arch:      linux/arm
    Experimental: false
  

• 操作系统和版本（例如 Linux、Windows、MacOS）：

  Distributor ID: Raspbian
  Description:    Raspbian GNU/Linux 9.4 (stretch)
  Release:        9.4
  Codename:       stretch
  

提前致谢，如果您需要更多信息，请告诉我。

加洛什

Answer 1

我看到此错误是因为 Kubernetes 不支持 docker 版本。从 Kubernetes 1.11 版本开始，支持的版本为 1.11.2 到 1.13.1 和 17.03.x。

我无法使用 OpenFaaS 测试解决方案。