我有一个小脚本在Pod中运行，它在我的注册表中插入最新的应用程序映像(dashboard:development)，然后将它们推送到正在运行的节点(通过守护进程)。
Thisdoes work，如下所示。
现在，我假设一旦App pod(如sp-pod-xx)请求此图像，kubelet不应该尝试重新拉取图像，即使设置了imagePullPolicy: Always。正如文档所说，kubelet比较摘要，如果不匹配，则只提取:
:每次kubelet启动容器时，kubelet都会查询容器映像注册表以将名称解析为映像摘要。如果kubelet有一个容器映像，它的摘要在本地缓存，那么kubelet使用它的缓存映像;否则，kubelet将提取具有解析摘要的映像，并使用该映像启动容器。
但是，即使摘要是相同的(我确实验证了这一点)，kubelet仍然重新提取图像。App pod和Daemonset pod也在同一个节点上运行。
知道为什么吗?
事件日志:
4m5s Normal Killing pod/image-puller-ds-ldbfz
3m57s Normal SuccessfulCreate daemonset/image-puller-ds Created pod: image-puller-ds-fcmts
3m57s Normal SuccessfulCreate daemonset/image-puller-ds Created pod: image-puller-ds-fhhds
3m57s Normal Pulled pod/image-puller-ds-fhhds Successfully pulled image "dashboard:development" in 192.717161ms
3m57s Normal Pulling pod/image-puller-ds-fhhds Pulling image "dashboard:development"
3m56s Normal Started pod/image-puller-ds-fhhds Started container image-puller
3m56s Normal Created pod/image-puller-ds-fcmts Created container image-puller
3m56s Normal Created pod/image-puller-ds-fhhds Created container image-puller
3m56s Normal Started pod/image-puller-ds-fcmts Started container image-puller
3m56s Normal Pulled pod/image-puller-ds-fhhds Container image "pause:0.0.1" already present on machine
3m55s Normal Created pod/image-puller-ds-fcmts Created container pause
3m55s Normal SuccessfulDelete daemonset/image-puller-ds Deleted pod: image-puller-ds-xt9vv
3m55s Normal Pulled pod/image-puller-ds-fcmts Container image "pause:0.0.1" already present on machine
3m55s Normal Created pod/image-puller-ds-fhhds Created container pause
3m55s Normal Started pod/image-puller-ds-fhhds Started container pause
3m55s Normal Started pod/image-puller-ds-fcmts Started container pause
3m55s Normal Killing pod/image-puller-ds-xt9vv Stopping container pause
3m54s Normal Killing pod/image-puller-ds-wgwzh Stopping container pause
3m54s Normal SuccessfulDelete daemonset/image-puller-ds Deleted pod: image-puller-ds-wgwzh
3m25s Normal Pulling pod/sp-pod-f3884032-1164-48e8-8213-c0c3856e573d Pulling image "dashboard:development"
3m25s Normal Pulled pod/sp-pod-f3884032-1164-48e8-8213-c0c3856e573d Successfully pulled image "dashboard:development" in 220.610781ms
3m25s Normal Created pod/sp-pod-f3884032-1164-48e8-8213-c0c3856e573d Created container sp-container-f3884032-1164-48e8-8213-c0c3856e573d
3m25s Normal Started pod/sp-pod-f3884032-1164-48e8-8213-c0c3856e573d Started container sp-container-f3884032-1164-48e8-8213-c0c3856e573d
版本:
Client Version: version.Info{Major:"1", Minor:"22", GitVersion:"v1.22.0", GitCommit:"c2b5237ccd9c0f1d600d3072634ca66cefdf272f", GitTreeState:"clean", BuildDate:"2021-08-04T18:03:20Z", GoVersion:"go1.16.6", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"23", GitVersion:"v1.23.12", GitCommit:"f941a31f4515c5ac03f5fc7ccf9a330e3510b80d", GitTreeState:"clean", BuildDate:"2022-11-09T17:12:33Z", GoVersion:"go1.17.13", Compiler:"gc", Platform:"linux/amd64"}
文档是错误的。您可以在这里阅读源代码。策略PullIfNotPresent将检查图像是否存在，但是Always直接跳过拉取图像。
在pod规范中使用imagepulpolicy: IfNotPresent来利用节点上已经存在的图像。
使用imagePullPolicy: Always从图像注册表中提取新图像。