containerd 像Docker一樣絲滑操作鏡像
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• 我們知道 Docker CLI 工具提供了需要增強用戶體驗的功能，containerd 同樣也提供一個對應的 CLI 工具：ctr，不過 ctr 的功能沒有 docker 完善，但是關於鏡像和容器的基本功能都是有的。接下來我們就先簡單介紹下 ctr 的使用。
➜ ~ ctr
NAME:
ctr -
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containerd CLI
USAGE:
ctr [global options] command [command options] [arguments...]
VERSION:
v1.5.5
DESCRIPTION:
ctr is an unsupported debug and administrative client for interacting
with the containerd daemon. Because it is unsupported, the commands,
options, and operations are not guaranteed to be backward compatible or
stable from release to release of the containerd project.
COMMANDS:
plugins, plugin provides information about containerd plugins
version print the client and server versions
containers, c, container manage containers
content manage content
events, event display containerd events
images, image, i manage images
leases manage leases
namespaces, namespace, ns manage namespaces
pprof provide golang pprof outputs for containerd
run run a container
snapshots, snapshot manage snapshots
tasks, t, task manage tasks
install install a new package
oci OCI tools
shim interact with a shim directly
help, h Shows a list of commands or help for one command
GLOBAL OPTIONS:
--debug enable debug output in logs
--address value, -a value address for containerd's GRPC server (default: "/run/containerd/containerd.sock") [$CONTAINERD_ADDRESS]
--timeout value total timeout for ctr commands (default: 0s)
--connect-timeout value timeout for connecting to containerd (default: 0s)
--namespace value, -n value namespace to use with commands (default: "default") [$CONTAINERD_NAMESPACE]
--help, -h show help
--version, -v print the version
鏡像操作
拉取鏡像
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• 拉取鏡像可以使用 ctr image pull 來完成，比如拉取 Docker Hub 官方鏡像 nginx:alpine，需要注意的是鏡像地址需要加上 docker.io Host 地址：
# ctr image pull docker.io/library/nginx:alpine
也可以使用 --platform 選項指定對應平臺的鏡像。當然對應的也有推送鏡像的命令 ctr image push，如果是私有鏡像則在推送的時候可以通過 --user 來自定義倉庫的用戶名和密碼。列出本地鏡像
# ctr image ls
# ctr image ls -q
使用 -q（--quiet） 選項可以只打印鏡像名稱
檢測本地鏡像
ctr image check
REF TYPE DIGEST STATUS SIZE UNPACKED
docker.io/library/nginx:alpine application/vnd.docker.distribution.manifest.list.v2+json sha256:bead42240255ae1485653a956ef41c9e458eb077fcb6dc664cbc3aa9701a05ce complete (7/7) 9.5 MiB/9.5 MiB true
# 主要查看其中的 STATUS，complete 表示鏡像是完整可用的狀態。重新打標籤
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• 同樣的我們也可以重新給指定的鏡像打一個 Tag：
# ctr image tag docker.io/library/nginx:alpine harbor.k8s.local/course/nginx:alpine
harbor.k8s.local/course/nginx:alpine
# ctr image ls -q
docker.io/library/nginx:alpine
harbor.k8s.local/course/nginx:alpine
刪除鏡像
# ctr image rm harbor.k8s.local/course/nginx:alpine
harbor.k8s.local/course/nginx:alpine
# ctr image ls -q
docker.io/library/nginx:alpine
加上 --sync 選項可以同步刪除鏡像和所有相關的資源。將鏡像導出爲壓縮包
# ctr image export nginx.tar.gz docker.io/library/nginx:alpine
從壓縮包導入鏡像
ctr image import nginx.tar.gzContainerd 像Docker一樣絲滑操作鏡像
https://mp.weixin.qq.com/s/fwwjeVUEY01ZZy6RlQELnA