Kubernetes：无法拉取图像

Question

在加入企业级 k8s/AWS EKS 之前，我使用 docker-desktop 在 Mac 上使用以下 Dockerfile 进行本地 k8s 测试：

FROM openjdk:11-jre-slim
ARG JAR_FILE=target/*.jar
COPY ${JAR_FILE} app.jar
ENTRYPOINT ["java","-jar","/app.jar"]

使用以下部署步骤到docker-desktop：

docker build . -t cpchung/rema

kubectl create deployment rema --image=cpchung/rema --dry-run -o=yaml > deployment.yaml
echo --- >> deployment.yaml
kubectl create service clusterip rema --tcp=8080:8080 --dry-run -o=yaml >> deployment.yaml
kubectl apply -f deployment.yaml

这会生成 deployment.yaml：

apiVersion: apps/v1
kind: Deployment
metadata:
  creationTimestamp: null
  labels:
    app: rema
  name: rema
spec:
  replicas: 1
  selector:
    matchLabels:
      app: rema
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: rema
    spec:
      containers:
      - image: cpchung/rema
        name: rema
        resources: {}
status: {}
---
apiVersion: v1
kind: Service
metadata:
  creationTimestamp: null
  labels:
    app: rema
  name: rema
spec:
  ports:
  - name: 8080-8080
    port: 8080
    protocol: TCP
    targetPort: 8080
  selector:
    app: rema
  type: ClusterIP
status:
  loadBalancer: {}

并使用以下运行状况检查测试部署：

kubectl port-forward svc/rema 8080:8080

curl localhost:8080/actuator/health

但我收到此错误：

robinhood $ kubectl get all
NAME                        READY   STATUS             RESTARTS   AGE
pod/rema-57df6cf5fc-px8pc   0/1     ImagePullBackOff   0          4m29s

NAME                 TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)    AGE
service/kubernetes   ClusterIP   10.96.0.1      <none>        443/TCP    18h
service/rema         ClusterIP   10.100.78.60   <none>        8080/TCP   152m

NAME                   READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/rema   0/1     1            0           4m29s

NAME                              DESIRED   CURRENT   READY   AGE
replicaset.apps/rema-57df6cf5fc   1         1         0       4m29s


robinhood $ kubectl logs rema-57df6cf5fc-px8pc
Error from server (BadRequest): container "rema" in pod "rema-57df6cf5fc-px8pc" is waiting to start: image can't be pulled

但我确实有来自码头工人的图像：

robinhood $ docker images
REPOSITORY                                      TAG                 IMAGE ID            CREATED             SIZE
cpchung/rema                                    latest              14a4957873cd        2 hours ago         224MB

这里可能有什么问题？我正在使用带有 docker-desktop 的 mac。

Answer 1

https://stackoverflow.com/a/52763242/3514300 应该会为你解决问题

在您的部署中添加imagePullPolicy: Never

默认情况下，没有标签的图像在 docker 中被赋予latest 标签。默认情况下，Kubernetes 会尝试为 latest 标签提取图像，但无法在 dockerhub 中找到该图像。 https://kubernetes.io/docs/concepts/containers/images/#updating-images

另一种方法是将您的图像也推送到 dockerhub。