一文吃透 Containerd：架构、部署与 ctr/nerdctl/crictl 全实操指南
·
容器管理工具Containerd
摘要：本文全面介绍了容器管理工具 Containerd，从其发展历程、架构设计到实际安装部署和日常使用。文章首先回顾了 Containerd 从 Docker 中独立出来的背景及其在云原生生态中的定位，详细解析了其 C/S 架构和插件化设计。接着，通过 CentOS Stream 8 环境演示了 YUM 和二进制两种安装方式，并深入讲解了使用
ctr命令进行容器镜像和容器生命周期管理。此外，文章还介绍了两个重要的 Containerd 客户端工具：nerdctl（兼容 Docker CLI）和crictl（遵循 CRI 规范），分别展示了它们在镜像、容器、网络、存储和命名空间管理方面的实践操作。最后通过对比表格总结了各工具的特点和适用场景，为读者提供了从理论到实践的完整 Containerd 学习路径。
一、Containerd介绍
1.前言
- 早在2016年3月，Docker 1.11的Docker Engine里就包含了containerd，而现在则是把containerd 从Docker Engine里彻底剥离出来，作为一个独立的开源项目独立发展，目标是提供一个更加开 放、稳定的容器运行基础设施。和原先包含在Docker Engine里containerd相比，独立的 containerd将具有更多的功能，可以涵盖整个容器运行时管理的所有需求。
- containerd并不是直接面向最终用户的，而是主要用于集成到更上层的系统里，比如Swarm, Kubernetes, Mesos等容器编排系统。
- containerd以Daemon的形式运行在系统上，通过暴露底层的gRPC API，上层系统可以通过这些 API管理机器上的容器。
- 每个containerd只负责一台机器，Pull镜像，对容器的操作（启动、停止等），网络，存储都是由 containerd完成。具体运行容器由runC负责，实际上只要是符合OCI规范的容器都可以支持。
- 对于容器编排服务来说，运行时只需要使用containerd+runC，更加轻量，容易管理。
- 独立之后containerd的特性演进可以和Docker Engine分开，专注容器运行时管理，可以更稳定。
2.Containerd前世今生
2013年docker公司在推出docker产品后,由于其对全球技术产生了一定的影响力，Google公司明显感觉 到自己公司内部所使用的Brog系统江湖地位受到的威胁，希望Docker公司能够与自己联合打造一款开源 的容器运行时作为Docker核心依赖，但Docker公司拒绝了；接着Google公司联合RedHat、IBM等公司 说服Docker公司把其容器核心技术libcontainer捐给中立社区(OCI,Open Container Intiative)，并更名为 runC。 为了进一步遏制Docker在未来技术市场影响力，避免在容器市场上Docker一家独大，Google公 司带领导RedHat、IBM等成立了CNCF(Cloud Native Computing Fundation)基金会，即云原生计算基金会。CNCF的目标很明确，既然在容器应用领域无法与Docker相抗衡，那就做Google更有经验的技术市 场------大规模容器编排应用场景，Google公司把自己内部使用的Brog系统开源------Kubernetes，也就是 我们今天所说的云原生技术生态。
2016年Docker公司推出了Docker Swarm，意在一统Docker生态，让Docker既可以实现容器应用管 理，也可以实现大规模容器编排，经过近1年左右时间的市场验证后，发现在容器编排方面无法独立抗衡 kubernetes,所以Docker公司于2017年正式宣布原生支持Kubernetes,至此，Docker在大规模容器编排 应用市场败下阵来，但是Docker依然不甘心失败，把Docker核心依赖Containerd捐给了CNCF，依此说 明Docker依旧是一个PaaS平台。
2020年CNCF基金会宣布Kubernetes 1.20版本将不再仅支持Docker容器管理工具，此事的起因主要也与 Docker捐给CNCF基金会的Containerd有关，早期为了实现Kubernetes能够使用Docker实现容器管理， 专门在Kubernetes组件中集成一个shim（垫片）技术，用来将Kubernetes容器运行时接口（CRI， Container Runntime Interface）调用翻译成Docker的API,这样就可以很好地使用Docker了，但是随着 Kubernetes在全球技术市场的广泛应用，有更多的容器管理工具的出现，它们都想能够借助于 Kubernetes被用户所使用，所以就提出标准化容器运行时接口，只要适配了这个接口就可以集成到 Kubernetes生态当中，所以Kubernetes取消了对shim的维护，并且由于Containerd技术的成功，可以 实现无缝对接Kubernetes，所以接下来Kubernetes容器运行时的主角是Containerd。
3.Containerd架构
3.1 架构图
Containerd设计的目的是为了嵌入到Kubernetes中使用，它是一个工业级的容器运行时，不提供给开发 人员和终端用户直接使用，这样就避免了与Docker产生竞争，但事实上，Containerd已经实现大多数容 器管理功能，例如：容器生命周期管理、容器镜像传输和管理、容器存储与网络管理等。
-
Containerd 采用标准的 C/S 架构
-
服务端通过 GRPC 协议提供稳定的 API
-
客户端通过调用服务端的 API 进行高级的操作
-
-
为了实现解耦，Containerd 将不同的职责划分给不同的组件，每个组件就相当于一个子系统 （subsystem）。连接不同子系统的组件被称为模块。
-
Containerd 两大子系统为：
-
Bundle : 在 Containerd 中，Bundle 包含了配置、元数据和根文件系统数据，你可以理解为 容器的文件系统。而 Bundle 子系统允许用户从镜像中提取和打包 Bundles。
-
Runtime : Runtime 子系统用来执行 Bundles，比如创建容器。
-
-
其中，每一个子系统的行为都由一个或多个模块协作完成（架构图中的 Core 部分）。每一种类型 的模块都以插件的形式集成到 Containerd 中，而且插件之间是相互依赖的。
-
例如，上图中的每一个长虚线的方框都表示一种类型的插件，包括 Service Plugin、Metadata Plugin、GC Plugin、Runtime Plugin 等，其中 Service Plugin 又会依赖 Metadata Plugin、GC Plugin 和 Runtime Plugin。每一个小方框都表示一个细分的插件，例如 Metadata Plugin 依赖 Containers Plugin、Content Plugin 等。
3.2 常用插件
- Content Plugin : 提供对镜像中可寻址内容的访问，所有不可变的内容都被存储在这里。
- Snapshot Plugin : 用来管理容器镜像的文件系统快照。镜像中的每一个 layer 都会被解压成文件 系统快照，类似于 Docker 中的 graphdriver 。
- Metrics : 暴露各个组件的监控指标。
3.3 架构缩略图
Containerd 被分为三个大块： Storage 、Metadata和 Runtime
3.4 与其它容器运行时工具性能对比
这是使用 bucketbench 对 Docker、crio 和 Containerd 的性能测试结果，包括启动、停止和删除容器， 以比较它们所耗的时间：
结论： Containerd 在各个方面都表现良好，总体性能优于 Docker 和 crio 。
二、Containerd安装
操作系统: CentOS Stream 8
1.YUM方式安装
基于 CentOS-Stream-8模板制作博客的模板克隆一台虚拟机命名为Containerd
安装必要工具
[root@localhost ~]# yum install -y yum-utils device-mapper-persistent-data lvm2 vim
安装Containerd
# 1.获取阿里云YUM源
[root@localhost ~]# yum-config-manager --add-repo
https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
[root@localhost ~]# yum makecache
# 2.查看YUM源中Containerd软件
[root@localhost ~]# yum list | grep containerd
containerd.io.x86_64 1.6.32-3.1.el8 docker-ce-stable
# 3.安装Containerd.io软件，即可安装Containerd
[root@localhost ~]# yum -y install containerd.io
# 4.使用rpm -qa命令查看是否安装
[root@localhost ~]# rpm -qa | grep containerd
containerd.io-1.6.32-3.1.el8.x86_64
# 5.设置containerd服务启动及开机自启动
[root@localhost ~]# systemctl enable containerd --now
[root@localhost ~]# systemctl status containerd
# 6.验证
# 安装Containerd时ctr命令亦可使用，ctr命令主要用于管理容器及容器镜像等。
# 使用ctr命令查看Containerd客户端及服务端相关信息
[root@localhost ~]# ctr version
Client:
Version: 1.6.32
Revision: 8b3b7ca2e5ce38e8f31a34f35b2b68ceb8470d89
Go version: go1.21.10
Server:
Version: 1.6.32
Revision: 8b3b7ca2e5ce38e8f31a34f35b2b68ceb8470d89
UUID: 979940af-68e0-4681-a560-189eeaefbdfc
2.二进制方式安装
Containerd有两种安装包：
- 第一种是containerd-xxx,这种包用于单机测试没问题，不包含runC，需要提前安装。
- 第二种是cri-containerd-cni-xxxx，包含runc和k8s里的所需要的相关文件。k8s集群里需要用到此 包。虽然包含runC，但是依赖系统中的seccomp（安全计算模式，是一种限制容器调用系统资源的 模式。）
2.1 安装Containerd
打开github官网，搜索containerd项目
找到1.6.32
往下翻，找到软件包下载，然后上传到centos
也可以右击，复制链接，wget下载
https://github.com/containerd/containerd/releases/download/v1.6.32/cri-containerd-cni-1.6.32-linux-amd64.tar.gz
# 1.下载Containerd安装包
# 此处是下载的第二种
[root@localhost ~]# wget https://github.com/containerd/containerd/releases/download/v1.6.32/cri-containerd-cni-1.6.32-linux-amd64.tar.gz
# 2.安装containerd
[root@localhost ~]# mkdir containerd
[root@localhost ~]# tar xf cri-containerd-cni-1.6.32-linux-amd64.tar.gz -C
containerd/
[root@localhost ~]# cd containerd/
[root@localhost containerd]# ls
cri-containerd.DEPRECATED.txt etc opt usr
[root@localhost containerd]# tree
.
├── cri-containerd.DEPRECATED.txt
├── etc #etc目录主要为containerd服务管理配置文件及cni虚拟网卡配置文件
│ ├── cni
│ │ └── net.d
│ │ └── 10-containerd-net.conflist #网络插件配置文件
│ ├── crictl.yaml
│ └── systemd
│ └── system
│ └── containerd.service #服务配置文件
├── opt #opt目录主要为gce环境中使用containerd配置文件及cni插件
│ ├── cni #网络插件
│ │ └── bin
│ │ ├── bandwidth
│ │ ├── bridge
│ │ ├── dhcp
│ │ ├── firewall
│ │ ├── host-device
│ │ ├── host-local
│ │ ├── ipvlan
│ │ ├── loopback
│ │ ├── macvlan
│ │ ├── portmap
│ │ ├── ptp
│ │ ├── sbr
│ │ ├── static
│ │ ├── tuning
│ │ ├── vlan
│ │ └── vrf
│ └── containerd
│ └── cluster
│ ├── gce
│ │ ├── cloud-init
│ │ │ ├── master.yaml
│ │ │ └── node.yaml
│ │ ├── cni.template
│ │ ├── configure.sh
│ │ └── env
│ └── version
└── usr #usr目录主要为containerd运行时文件，包含runc
└── local # bin,sbin命令
├── bin
│ ├── containerd
│ ├── containerd-shim
│ ├── containerd-shim-runc-v1
│ ├── containerd-shim-runc-v2
│ ├── containerd-stress
│ ├── crictl
│ ├── critest
│ ├── ctd-decoder
│ └── ctr
└── sbin
└── runc
16 directories, 36 files
#查看containerd.service文件，了解containerd文件安装位置
[root@localhost containerd]# cat etc/systemd/system/containerd.service
# Copyright The containerd Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
[Unit]
Description=containerd container runtime
Documentation=https://containerd.io
After=network.target local-fs.target
[Service]
ExecStartPre=-/sbin/modprobe overlay
ExecStart=/usr/local/bin/containerd #查看此位置,把containerd二进制文件放置于此处即可完成安装。
Type=notify
Delegate=yes
KillMode=process
Restart=always
RestartSec=5
# Having non-zero Limit*s causes performance problems due to accounting overhead
# in the kernel. We recommend using cgroups to do container-local accounting.
LimitNPROC=infinity
LimitCORE=infinity
LimitNOFILE=infinity
# Comment TasksMax if your systemd version does not supports it.
# Only systemd 226 and above support this version.
TasksMax=infinity
OOMScoreAdjust=-999
[Install]
WantedBy=multi-user.target
#复制containerd运行时文件至系统
[root@localhost containerd]# cp usr/local/bin/* /usr/local/bin
#添加containerd.service文件至系统
[root@localhost containerd]# cp etc/systemd/system/containerd.service /usr/lib/systemd/system/containerd.service
# 生成containerd模块配置文件，可以自定义一下配置，如有私有镜像仓库等，按需配置
[root@localhost containerd]# mkdir /etc/containerd
[root@localhost containerd]# containerd config default >
/etc/containerd/config.toml
[root@localhost containerd]# cat /etc/containerd/config.toml
disabled_plugins = []
imports = []
oom_score = 0
plugin_dir = ""
required_plugins = []
root = "/var/lib/containerd"
state = "/run/containerd"
temp = ""
version = 2
[cgroup]
path = ""
[debug]
address = ""
format = ""
gid = 0
level = ""
uid = 0
[grpc]
address = "/run/containerd/containerd.sock"
gid = 0
max_recv_message_size = 16777216
max_send_message_size = 16777216
tcp_address = ""
tcp_tls_ca = ""
tcp_tls_cert = ""
tcp_tls_key = ""
uid = 0
[metrics]
address = ""
grpc_histogram = false
[plugins]
[plugins."io.containerd.gc.v1.scheduler"]
deletion_threshold = 0
mutation_threshold = 100
pause_threshold = 0.02
schedule_delay = "0s"
startup_delay = "100ms"
[plugins."io.containerd.grpc.v1.cri"]
device_ownership_from_security_context = false
disable_apparmor = false
disable_cgroup = false
disable_hugetlb_controller = true
disable_proc_mount = false
disable_tcp_service = true
drain_exec_sync_io_timeout = "0s"
enable_selinux = false
enable_tls_streaming = false
enable_unprivileged_icmp = false
enable_unprivileged_ports = false
ignore_deprecation_warnings = []
ignore_image_defined_volumes = false
max_concurrent_downloads = 3
max_container_log_line_size = 16384
netns_mounts_under_state_dir = false
restrict_oom_score_adj = false
sandbox_image = "registry.k8s.io/pause:3.6"
selinux_category_range = 1024
stats_collect_period = 10
stream_idle_timeout = "4h0m0s"
stream_server_address = "127.0.0.1"
stream_server_port = "0"
systemd_cgroup = false
tolerate_missing_hugetlb_controller = true
unset_seccomp_profile = ""
[plugins."io.containerd.grpc.v1.cri".cni]
bin_dir = "/opt/cni/bin"
conf_dir = "/etc/cni/net.d"
conf_template = ""
ip_pref = ""
max_conf_num = 1
[plugins."io.containerd.grpc.v1.cri".containerd]
default_runtime_name = "runc"
disable_snapshot_annotations = true
discard_unpacked_layers = false
ignore_rdt_not_enabled_errors = false
no_pivot = false
snapshotter = "overlayfs"
[plugins."io.containerd.grpc.v1.cri".containerd.default_runtime]
base_runtime_spec = ""
cni_conf_dir = ""
cni_max_conf_num = 0
container_annotations = []
pod_annotations = []
privileged_without_host_devices = false
runtime_engine = ""
runtime_path = ""
runtime_root = ""
runtime_type = ""
[plugins."io.containerd.grpc.v1.cri".containerd.default_runtime.options]
[plugins."io.containerd.grpc.v1.cri".containerd.runtimes]
[plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc]
base_runtime_spec = ""
cni_conf_dir = ""
cni_max_conf_num = 0
container_annotations = []
pod_annotations = []
privileged_without_host_devices = false
runtime_engine = ""
runtime_path = ""
runtime_root = ""
runtime_type = "io.containerd.runc.v2"
[plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc.options]
BinaryName = ""
CriuImagePath = ""
CriuPath = ""
CriuWorkPath = ""
IoGid = 0
IoUid = 0
NoNewKeyring = false
NoPivotRoot = false
Root = ""
ShimCgroup = ""
SystemdCgroup = false
[plugins."io.containerd.grpc.v1.cri".containerd.untrusted_workload_runtime]
base_runtime_spec = ""
cni_conf_dir = ""
cni_max_conf_num = 0
container_annotations = []
pod_annotations = []
privileged_without_host_devices = false
runtime_engine = ""
runtime_path = ""
runtime_root = ""
runtime_type = ""
[plugins."io.containerd.grpc.v1.cri".containerd.untrusted_workload_runtime.options]
[plugins."io.containerd.grpc.v1.cri".image_decryption]
key_model = "node"
[plugins."io.containerd.grpc.v1.cri".registry]
config_path = ""
[plugins."io.containerd.grpc.v1.cri".registry.auths]
[plugins."io.containerd.grpc.v1.cri".registry.configs]
[plugins."io.containerd.grpc.v1.cri".registry.headers]
[plugins."io.containerd.grpc.v1.cri".registry.mirrors]
[plugins."io.containerd.grpc.v1.cri".x509_key_pair_streaming]
tls_cert_file = ""
tls_key_file = ""
[plugins."io.containerd.internal.v1.opt"]
path = "/opt/containerd"
[plugins."io.containerd.internal.v1.restart"]
interval = "10s"
[plugins."io.containerd.internal.v1.tracing"]
[plugins."io.containerd.metadata.v1.bolt"]
content_sharing_policy = "shared"
[plugins."io.containerd.monitor.v1.cgroups"]
no_prometheus = false
[plugins."io.containerd.runtime.v1.linux"]
no_shim = false
runtime = "runc"
runtime_root = ""
shim = "containerd-shim"
shim_debug = false
[plugins."io.containerd.runtime.v2.task"]
platforms = ["linux/amd64"]
sched_core = false
[plugins."io.containerd.service.v1.diff-service"]
default = ["walking"]
[plugins."io.containerd.service.v1.tasks-service"]
rdt_config_file = ""
[plugins."io.containerd.snapshotter.v1.aufs"]
root_path = ""
[plugins."io.containerd.snapshotter.v1.btrfs"]
root_path = ""
[plugins."io.containerd.snapshotter.v1.devmapper"]
async_remove = false
base_image_size = ""
discard_blocks = false
fs_options = ""
fs_type = ""
pool_name = ""
root_path = ""
[plugins."io.containerd.snapshotter.v1.native"]
root_path = ""
[plugins."io.containerd.snapshotter.v1.overlayfs"]
mount_options = []
root_path = ""
sync_remove = false
upperdir_label = false
[plugins."io.containerd.snapshotter.v1.zfs"]
root_path = ""
[plugins."io.containerd.tracing.processor.v1.otlp"]
[proxy_plugins]
[stream_processors]
[stream_processors."io.containerd.ocicrypt.decoder.v1.tar"]
accepts = ["application/vnd.oci.image.layer.v1.tar+encrypted"]
args = ["--decryption-keys-path", "/etc/containerd/ocicrypt/keys"]
env =
["OCICRYPT_KEYPROVIDER_CONFIG=/etc/containerd/ocicrypt/ocicrypt_keyprovider.conf"]
path = "ctd-decoder"
returns = "application/vnd.oci.image.layer.v1.tar"
[stream_processors."io.containerd.ocicrypt.decoder.v1.tar.gzip"]
accepts = ["application/vnd.oci.image.layer.v1.tar+gzip+encrypted"]
args = ["--decryption-keys-path", "/etc/containerd/ocicrypt/keys"]
env =
["OCICRYPT_KEYPROVIDER_CONFIG=/etc/containerd/ocicrypt/ocicrypt_keyprovider.conf"]
path = "ctd-decoder"
returns = "application/vnd.oci.image.layer.v1.tar+gzip"
[timeouts]
"io.containerd.timeout.bolt.open" = "0s"
"io.containerd.timeout.shim.cleanup" = "5s"
"io.containerd.timeout.shim.load" = "5s"
"io.containerd.timeout.shim.shutdown" = "3s"
"io.containerd.timeout.task.state" = "2s"
[ttrpc]
address = ""
gid = 0
uid = 0
#启动containerd并验证
[root@localhost ~]# systemctl enable containerd --now
[root@localhost ~]# systemctl status containerd
[root@localhost ~]# ctr version
Client:
Version: v1.6.32
Revision: 8b3b7ca2e5ce38e8f31a34f35b2b68ceb8470d89
Go version: go1.21.10
Server:
Version: v1.6.32
Revision: 8b3b7ca2e5ce38e8f31a34f35b2b68ceb8470d89
UUID: 3ece67b1-4d8e-4059-afae-b837672ede83
2.2 安装runC
由于二进制包中提供的runC默认需要系统中安装seccomp支持，需要单独安装，且不同版本runC对 seccomp版本要求一致，所以建议单独下载runC 二进制包进行安装，里面包含了seccomp模块支持
下载地址： https://github.com/opencontainers/runc/releases
# 使用wget下载runc
[root@localhost ~]# wget https://github.com/opencontainers/runc/releases/download/v1.3.0/runc.amd64
# 安装runc
[root@localhost ~]# mv runc.amd64 /usr/sbin/runc
# 为runc添加可执行权限
[root@localhost ~]# chmod +x /usr/sbin/runc
# 使用runc命令验证是否安装成功
[root@localhost ~]# runc -v
runc version 1.3.0
commit: v1.3.0-0-g4ca628d1
spec: 1.2.1
go: go1.23.8
libseccomp: 2.5.6
三、Containerd容器镜像管理
3.1.帮助命令
- docker使用docker images命令管理镜像
- 单机containerd使用ctr images命令管理镜像,containerd本身的CLI
- k8s中containerd使用crictl images命令管理镜像,Kubernetes社区的专用CLI工具
#命令帮助
[root@localhost ~]# ctr --help
NAME:
ctr -
__
_____/ /______
/ ___/ __/ ___/
/ /__/ /_/ /
\___/\__/_/
containerd CLI
USAGE:
ctr [global options] command [command options] [arguments...]
VERSION:
v1.6.32
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
deprecations
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
# 子命令帮助
[root@localhost ~]# ctr images --help
NAME:
ctr images - manage images
USAGE:
ctr images command [command options] [arguments...]
COMMANDS:
check check existing images to ensure all content is available locally
export export images
import import images
list, ls list images known to containerd
mount mount an image to a target path
unmount unmount the image from the target
pull pull an image from a remote
push push an image to a remote
delete, del, remove, rm remove one or more images by reference
tag tag an image
label set and clear labels for an image
convert convert an image
OPTIONS:
--help, -h show help
3.2.查看镜像
[root@docker ~]# ctr images list
REF TYPE DIGEST SIZE PLATFORMS LABELS
[root@docker ~]# ctr images ls
REF TYPE DIGEST SIZE PLATFORMS LABELS
[root@docker ~]# ctr image list
REF TYPE DIGEST SIZE PLATFORMS LABELS
[root@docker ~]# ctr image ls
REF TYPE DIGEST SIZE PLATFORMS LABELS
[root@docker ~]# ctr i list
REF TYPE DIGEST SIZE PLATFORMS LABELS
[root@docker ~]# ctr i ls
REF TYPE DIGEST SIZE PLATFORMS LABEL
3.3.下载镜像
containerd支持oci标准的镜像，所以可以直接使用docker官方或dockerfile构建的镜像
# 这里ctr命令pull镜像时，不能直接把镜像名字写成nginx:alpine
[root@localhost ~]# ctr images pull 054b8ac70e8010d90f2ac00ef29e6580.mirror.swr.myhuaweicloud.com/library/nginx:latest
# 验证现象
[root@localhost ~]# ctr image ls
REF TYPE DIGEST
SIZE PLATFORMS
LABELS
054b8ac70e8010d90f2ac00ef29e6580.mirror.swr.myhuaweicloud.com/library/nginx:lates
t application/vnd.oci.image.index.v1+json
sha256:84ec966e61a8c7846f509da7eb081c55c1d56817448728924a87ab32f12a72fb 68.9 MiB
linux/386,linux/amd64,linux/arm/v5,linux/arm/v7,linux/arm64/v8,linux/mips64le,lin
ux/ppc64le,linux/s390x,unknown/unknown -
3.4.镜像挂载
方便查看镜像中包含的内容
# 挂载
[root@localhost ~]# ctr images mount 054b8ac70e8010d90f2ac00ef29e6580.mirror.swr.myhuaweicloud.com/library/nginx:latest /mnt
sha256:3c1159cd77f83ede793fc21502ae30b39b04378b6b1b625451d701d555cc1cb9
/mnt
# 查看挂载
[root@localhost ~]# ls /mnt
bin boot dev docker-entrypoint.d docker-entrypoint.sh etc home lib lib64 media mnt opt proc root run sbin srv sys tmp usr var
# 卸载
[root@localhost ~]# umount /mnt
3.5.镜像导出
#--platform linux/amd64,导出指定平台镜像
[root@localhost ~]# ctr i export --platform linux/amd64 nginx.tar 054b8ac70e8010d90f2ac00ef29e6580.mirror.swr.myhuaweicloud.com/library/nginx:latest
[root@localhost ~]# ls
nginx.tar
3.6.镜像删除
# ctr image rm帮助
[root@localhost ~]# ctr image rm --help
NAME:
ctr images delete - remove one or more images by reference
USAGE:
ctr images delete [command options] [flags] <ref> [<ref>, ...]
DESCRIPTION:
remove one or more images by reference
OPTIONS:
--sync Synchronously remove image and all associated resources
# 删除指定镜像
[root@localhost ~]# ctr image rm 054b8ac70e8010d90f2ac00ef29e6580.mirror.swr.myhuaweicloud.com/library/nginx:latest
054b8ac70e8010d90f2ac00ef29e6580.mirror.swr.myhuaweicloud.com/library/nginx:latest
# 验证现象
[root@localhost ~]# ctr image ls
REF TYPE DIGEST SIZE PLATFORMS LABELS
3.7.镜像导入
# 导入镜像
[root@localhost ~]# ctr images import --platform linux/amd64 nginx.tar
unpacking
054b8ac70e8010d90f2ac00ef29e6580.mirror.swr.myhuaweicloud.com/library/nginx:latest
(sha256:84ec966e61a8c7846f509da7eb081c55c1d56817448728924a87ab32f12a72fb)...done
# 验证现象
[root@localhost ~]# ctr image ls
REF TYPE DIGEST
SIZE PLATFORMS
LABELS
054b8ac70e8010d90f2ac00ef29e6580.mirror.swr.myhuaweicloud.com/library/nginx:lates
t application/vnd.oci.image.index.v1+json
sha256:84ec966e61a8c7846f509da7eb081c55c1d56817448728924a87ab32f12a72fb 68.9 MiB
linux/386,linux/amd64,linux/arm/v5,linux/arm/v7,linux/arm64/v8,linux/mips64le,lin
ux/ppc64le,linux/s390x,unknown/unknown -
3.8.修改镜像tag
# 把054b8ac70e8010d90f2ac00ef29e6580.mirror.swr.myhuaweicloud.com/library/nginx:latest 修改为 nginx:latest
[root@localhost ~]# ctr images tag 054b8ac70e8010d90f2ac00ef29e6580.mirror.swr.myhuaweicloud.com/library/nginx:latest nginx:latest
nginx:latest
# 验证现象
[root@localhost ~]# ctr image ls
REF TYPE DIGEST
SIZE PLATFORMS
LABELS
054b8ac70e8010d90f2ac00ef29e6580.mirror.swr.myhuaweicloud.com/library/nginx:lates
t application/vnd.oci.image.index.v1+json
sha256:84ec966e61a8c7846f509da7eb081c55c1d56817448728924a87ab32f12a72fb 68.9 MiB
linux/386,linux/amd64,linux/arm/v5,linux/arm/v7,linux/arm64/v8,linux/mips64le,lin
ux/ppc64le,linux/s390x,unknown/unknown -
nginx:latest
application/vnd.oci.image.index.v1+json
sha256:84ec966e61a8c7846f509da7eb081c55c1d56817448728924a87ab32f12a72fb 68.9 MiB
linux/386,linux/amd64,linux/arm/v5,linux/arm/v7,linux/arm64/v8,linux/mips64le,lin
ux/ppc64le,linux/s390x,unknown/unknown -
四、Containerd容器管理
1.获取命令帮助
[root@localhost ~]# ctr --help
NAME:
ctr -
__
_____/ /______
/ ___/ __/ ___/
/ /__/ /_/ /
\___/\__/_/
containerd CLI
USAGE:
ctr [global options] command [command options] [arguments...]
VERSION:
v1.6.32
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
deprecations
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
[root@localhost ~]# ctr container --help #获取创建静态容器命令帮助 使用`ctr container create `命令创建容器后，容器并没有处于运行状态，其只是一个静态的容器。这个 container 对象只是包含了运行一个容器所需的资源及配置的数据结构，例如： namespaces、rootfs 和容器的配置都已经初始化成功了，只是用户进程(本案例为nginx)还没有启动。需要使用`ctr tasks`命令才能获取一个动态容器。
NAME:
ctr containers - manage containers
USAGE:
ctr containers command [command options] [arguments...]
COMMANDS:
create create container
delete, del, remove, rm delete one or more existing containers
info get info about a container
list, ls list containers
label set and clear labels for a container
checkpoint checkpoint a container
restore restore a container from checkpoint
OPTIONS:
--help, -h show help
[root@localhost ~]# ctr run --help # 使用ctr run命令可以创建一个静态容器并使其运行。一步到位运行容器。
NAME:
ctr run - run a container
USAGE:
ctr run [command options] [flags] Image|RootFS ID [COMMAND] [ARG...]
OPTIONS:
--rm remove the container after running,
cannot be used with --detach
--null-io send all IO to /dev/null
--log-uri value log uri
--detach, -d detach from the task after it has
started execution, cannot be used with --rm
--fifo-dir value directory used for storing IO FIFOs
--cgroup value cgroup path (To disable use of cgroup, set to "" explicitly)
--platform value run image for specific platform
--cni enable cni networking for the container
--runc-binary value specify runc-compatible binary
--runc-root value specify runc-compatible root
--runc-systemd-cgroup start runc with systemd cgroup manager
--uidmap container-uid:host-uid:length run inside a user namespace with the specified UID mapping range; specified with the format container-uid:hostuid:length
--gidmap container-gid:host-gid:length run inside a user namespace with the specified GID mapping range; specified with the format container-gid:hostgid:length
--remap-labels provide the user namespace ID
remapping to the snapshotter via label options; requires snapshotter support
--cpus value set the CFS cpu quota (default: 0)
--cpu-shares value set the cpu shares (default: 1024)
--snapshotter value snapshotter name. Empty value stands
for the default value. [$CONTAINERD_SNAPSHOTTER]
--snapshotter-label value labels added to the new snapshot for this container.
--config value, -c value path to the runtime-specific spec
config file
--cwd value specify the working directory of the
process
--env value specify additional container
environment variables (e.g. FOO=bar)
--env-file value specify additional container
environment variables in a file(e.g. FOO=bar, one per line)
--label value specify additional labels (e.g.
foo=bar)
--annotation value specify additional OCI annotations
(e.g. foo=bar)
--mount value specify additional container mount
(e.g. type=bind,src=/tmp,dst=/host,options=rbind:ro)
--net-host enable host networking for the
container
--privileged run privileged container
--read-only set the containers filesystem as
readonly
--runtime value runtime name (default:
"io.containerd.runc.v2")
--runtime-config-path value optional runtime config path
--tty, -t allocate a TTY for the container
--with-ns value specify existing Linux namespaces to join at container runtime (format '<nstype>:<path>')
--pid-file value file path to write the task's pid
--gpus value add gpus to the container
--allow-new-privs turn off OCI spec's NoNewPrivileges
feature flag
--memory-limit value memory limit (in bytes) for the
container (default: 0)
--device value file path to a device to add to the container; or a path to a directory tree of devices to add to the container
--cap-add value add Linux capabilities (Set
capabilities with 'CAP_' prefix)
--cap-drop value drop Linux capabilities (Set
capabilities with 'CAP_' prefix)
--seccomp enable the default seccomp profile
--seccomp-profile value file path to custom seccomp profile.
seccomp must be set to true, before using seccomp-profile
--apparmor-default-profile value enable AppArmor with the default
profile with the specified name, e.g. "cri-containerd.apparmor.d"
--apparmor-profile value enable AppArmor with an existing
custom profile
--rdt-class value name of the RDT class to associate the
container with. Specifies a Class of Service (CLOS) for cache and memory
bandwidth management.
--rootfs use custom rootfs that is not managed
by containerd snapshotter
--no-pivot disable use of pivot-root (linux only)
--cpu-quota value Limit CPU CFS quota (default: -1)
--cpu-period value Limit CPU CFS period (default: 0)
--rootfs-propagation value set the propagation of the container
rootfs
2.查看容器(container表示静态容器，可用c缩写代表container)
[root@localhost ~]# ctr container ls # 可以简写为 ctr c ls
CONTAINER IMAGE RUNTIME
3.查看任务(task表示容器里跑的进程, 可用t缩写代表task)
[root@localhost ~]# ctr task ls # 可以简写为 ctr t ls
TASK PID STATUS
4.创建静态容器
[root@localhost ~]# ctr container create nginx:latest nginx1
[root@localhost ~]# ctr container ls
CONTAINER IMAGE RUNTIME
nginx1 nginx:latest io.containerd.runc.v2
[root@localhost ~]# ctr container info nginx1
5.静态容器启动为动态容器
[root@localhost ~]# ctr task ls
TASK PID STATUS
[root@localhost ~]# ctr task start -d nginx1 #启动task，即表示在容器中运行了进程，即为动态容器 -d 后台
[root@localhost ~]# ctr task ls #容器是以宿主机进程的方式存在的
TASK PID STATUS
nginx1 22614 RUNNING
[root@localhost ~]# ps aux | grep 22614
root 22614 0.0 0.0 11468 7196 ? Ss 15:40 0:00 nginx: master
process nginx -g daemon off;
root 22969 0.0 0.0 12216 1104 pts/0 S+ 15:41 0:00 grep --
color=auto 22614
6.进入容器操作
[root@localhost ~]# ctr task exec --exec-id $RANDOM -t nginx1 /bin/sh #为exec进程设定一个id，可以随意输入，只要保证唯一即可，也可使用$RANDOM变量
#
7.直接运行一个动态容器
[root@localhost ~]# ctr run -d --net-host nginx:latest nginx2 # --net-host 代表容器的IP就是宿主机的IP(相当于docker里的host类型网络)
8.暂停容器
[root@localhost ~]# ctr tasks pause nginx2
[root@localhost ~]# ctr task ls
TASK PID STATUS
nginx1 22614 RUNNING
nginx2 25569 PAUSED #状态为PAUSED，表示暂停
9.恢复容器
[root@localhost ~]# ctr tasks resume nginx2
[root@localhost ~]# ctr task ls
TASK PID STATUS
nginx1 22614 RUNNING
nginx2 25569 RUNNING #恢复RUNNING
10.停止容器
[root@localhost ~]# ctr tasks kill nginx2
[root@localhost ~]# ctr tasks ls
TASK PID STATUS
nginx1 22614 RUNNING
nginx2 25569 STOPPED #容器停止后STATUS为STOPPED
11.删除容器
[root@localhost ~]# ctr tasks delete nginx2 #必须先停止tasks或先删除task，再删除容
器
[root@localhost ~]# ctr tasks ls
TASK PID STATUS
nginx1 22614 RUNNING
[root@localhost ~]# ctr container ls # 查看静态容器，确认其还存在于系统中
CONTAINER IMAGE RUNTIME
nginx1 nginx:latest io.containerd.runc.v2
nginx2 nginx:latest io.containerd.runc.v2
[root@localhost ~]# ctr container delete nginx2
[root@localhost ~]# ctr container ls
CONTAINER IMAGE RUNTIME
nginx1 nginx:latest io.containerd.runc.v2
五、Containerd使用私有容器镜像仓库 Harbor
# 手动在containerd宿主机上添加此配置信息,如果域名解析已存在忽略
[root@localhost ~]# vim /etc/hosts
192.168.108.30 my.harbor.com
# harbor仓库需要提前在192.168.108.30上部署(参考docker教案)，镜像需要提前传到harbor上，如果没有使用https可以使用--plain-http 指定http协议
[root@localhost ~]# ctr image pull --plain-http 192.168.108.30/cloud/nginx:latest
# 上传镜像到Harbor
[root@localhost ~]# ctr images tag nginx:latest my.harbor.com/cloud/nginx:latest
[root@localhost ~]# ctr image push --platform linux/amd64 --plain-http --user
"images_admin:Cloud12#$" my.harbor.com/cloud/nginx:latest
manifest-sha256:6533ddd664582430971e93e69cf343e3bfffceadeaaa97d4379c4d7a29f21d47:
done
|++++++++++++++++++++++++++++++++++++++|
config-sha256:2cd1d97f893f70cee86a38b7160c30e5750f3ed6ad86c598884ca9c6a563a501:
done
|++++++++++++++++++++++++++++++++++++++|
elapsed: 0.1 s
六、Containerd NameSpace管理
containerd中namespace的作用为隔离运行的容器，可以实现运行多个容器
1.列出已有namespace
[root@localhost ~]# ctr namespace ls
NAME LABELS
default #containerd默认工作在default命名空间
[root@docker ~]# ctr namespace ls #在docker环境中打
NAME LABELS
moby #docker默认工作在moby空间
2.创建namespace
[root@localhost ~]# ctr namespace create myns
[root@localhost ~]# ctr namespace create testns
[root@localhost ~]# ctr namespace ls
NAME LABELS
default
myns
testns
3.删除namespace
[root@localhost ~]# ctr namespace rm testns
testns
[root@localhost ~]# ctr namespace ls
NAME LABELS
default
myns
4.查看指定namespace中镜像
[root@localhost ~]# ctr -n myns images ls
REF TYPE DIGEST SIZE PLATFORMS LABELS
5.查看指定namespace中是否有用户进程在运行
[root@localhost ~]# ctr -n myns tasks ls
TASK PID STATUS
6.在指定namespace中下载容器镜像
[root@localhost ~]# ctr -n myns images pull 054b8ac70e8010d90f2ac00ef29e6580.mirror.swr.myhuaweicloud.com/library/nginx:latest
[root@localhost ~]# ctr -n myns images ls
REF TYPE DIGEST
SIZE PLATFORMS
LABELS
054b8ac70e8010d90f2ac00ef29e6580.mirror.swr.myhuaweicloud.com/library/nginx:latest application/vnd.oci.image.index.v1+json
sha256:84ec966e61a8c7846f509da7eb081c55c1d56817448728924a87ab32f12a72fb 68.9 MiB
linux/386,linux/amd64,linux/arm/v5,linux/arm/v7,linux/arm64/v8,linux/mips64le,lin
ux/ppc64le,linux/s390x,unknown/unknown -
7.在指定namespace中创建静态容器
[root@localhost ~]# ctr -n myns container create
054b8ac70e8010d90f2ac00ef29e6580.mirror.swr.myhuaweicloud.com/library/nginx:lates
t mynginx
8.查看在指定namespace中创建的容器
[root@localhost ~]# ctr -n myns container ls
CONTAINER IMAGE
RUNTIME
mynginx
054b8ac70e8010d90f2ac00ef29e6580.mirror.swr.myhuaweicloud.com/library/nginx:latest io.containerd.runc.v2
[root@localhost ~]# ctr -n myns task start -d mynginx
[root@localhost ~]# ctr -n myns tasks ls
TASK PID STATUS
mynginx 5873 RUNNING
七、nerdctl 实践
nerdctl 安装
我们推荐使用 nerdctl 管理containerd，命令语法与 docker 一致。
截止 2023-05-24 最新版本是 v 1.4.0
github项目地址：https://github.com/containerd/nerdctl/releases
cni插件项目地址：https://github.com/containernetworking/plugins/releases
# 下载并安装
[root@localhost ~]# wget https://github.com/containerd/nerdctl/releases/download/v1.4.0/nerdctl-1.4.0linux-amd64.tar.gz
[root@localhost ~]# tar -xf nerdctl-1.4.0-linux-amd64.tar.gz -C /usr/bin/
# 配置nerdctl命令自动补全
[root@localhost ~]# nerdctl completion bash > /etc/bash_completion.d/nerdctl
[root@localhost ~]# source /etc/bash_completion.d/nerdctl


# 下载nerdctl所需要的cni插件
[root@localhost ~]# wget https://github.com/containernetworking/plugins/releases/download/v1.3.0/cniplugins-linux-amd64-v1.3.0.tgz
[root@localhost ~]# mkdir -p /opt/cni/bin
[root@localhost ~]# tar -xf cni-plugins-linux-amd64-v1.3.0.tgz -C /opt/cni/bin
如果nerdctl补全是报错信息如下：
_get_comp_words_by_ref: command not found
解决方法：安装 bash-completion
[root@localhost ~]# yum install -y bash-completion
配置镜像加速
#编辑containerd的配置文件config.toml，如果不存在，需要手动生成，方法 containerd config default > /etc/containerd/config.toml，在配置文件中搜索关键字“config_path”，在其下面添加镜像加速参数
[root@docker ~]# containerd config default > /etc/containerd/config.toml
[root@control ~]# vim /etc/containerd/config.toml
146 [plugins."io.containerd.grpc.v1.cri".registry]
147 config_path = "/etc/containerd/certs.d" #配置这里
[root@control ~]# mkdir -p /etc/containerd/certs.d/docker.io
[root@localhost ~]# vim /etc/containerd/certs.d/docker.io/hosts.toml
server = "https://054b8ac70e8010d90f2ac00ef29e6580.mirror.swr.myhuaweicloud.com"
[host."https://054b8ac70e8010d90f2ac00ef29e6580.mirror.swr.myhuaweicloud.com"]
capabilities = ["pull", "resolve"]
#重启containerd服务生效
[root@control ~]# systemctl restart containerd
nerdctl 管理镜像
[root@localhost ~]# nerdctl image <按tab键><按tab键>
build (Build an image from a Dockerfile. Needs buildkitd to be running.)
convert (convert an image)
decrypt (decrypt an image)
encrypt (encrypt image layers)
history (Show the history of an image)
inspect (Display detailed information on one or more images.)
load (Load an image from a tar archive or STDIN)
ls (List images)
prune (Remove unused images)
pull (Pull an image from a registry. Optionally specify "ipfs://" or "ipns://" scheme to pull image from IPFS.)
push (Push an image or a repository to a registry. Optionally specify "ipfs://" or "ipns://" scheme to push image to IPFS.)
save (Save one or more images to a tar archive (streamed to STDOUT by default))
tag (Create a tag TARGET_IMAGE that refers to SOURCE_IMAGE)
ls
作用：查看本地镜像清单。
示例：
[root@localhost ~]# nerdctl image ls
REPOSITORY TAG IMAGE ID CREATED PLATFORM SIZE BLOB SIZE
# 可简写如下
[root@localhost ~]# nerdctl images
pull
作用：从网络上下载镜像。
示例：
#下载镜像busybox
[root@localhost ~]# nerdctl image pull busybox
# 可简写如下下载httpd
[root@localhost ~]# nerdctl pull httpd
[root@localhost ~]# nerdctl image ls
REPOSITORY TAG IMAGE ID CREATED PLATFORM SIZE BLOB SIZE
busybox latest f9a104fddb33 19 minutes ago linux/amd64 4.1 MiB 2.1 MiB
httpd latest fbc12199ccad 44 minutes ago linux/amd64 152.4 MiB 55.8 MiB
rm
作用：删除本地不用的镜像。
示例：
[root@localhost ~]# nerdctl image rm httpd
[root@localhost ~]# nerdctl rmi busybox
[root@localhost ~]# nerdctl images
REPOSITORY TAG IMAGE ID CREATED PLATFORM SIZE BLOB SIZE
busybox latest f9a104fddb33 19 minutes ago linux/amd64 4.1 MiB 2.1 MiB
tag
作用：给镜像打标签。
示例：
[root@localhost ~]# nerdctl tag busybox busybox_containerd
[root@localhost ~]# nerdctl images
REPOSITORY TAG IMAGE ID CREATED PLATFORM SIZE BLOB SIZE
busybox latest f9a104fddb33 34 minutes ago linux/amd64 4.1 MiB 2.1 MiB
busybox_containerd latest f9a104fddb33 1 minutes ago linux/amd64 4.1 MiB 2.1 MiB
save
作用：将本地镜像导出为文件。
示例：
[root@localhost ~]# nerdctl image save busybox -o busybox.tar
# 可简写为
[root@localhost ~]# nerdctl save busybox -o busybox.tar
# 删除镜像
[root@localhost ~]# nerdctl image rm busybox
[root@localhost ~]# nerdctl images
REPOSITORY TAG IMAGE ID CREATED PLATFORM SIZE BLOB SIZE
busybox_containerd latest f9a104fddb33 2 minutes ago linux/amd64 4.1 MiB 2.1 MiB
load
作用：导入tar文件中镜像。
示例：
[root@localhost ~]# nerdctl image load -i busybox.tar
# 可简写为
[root@localhost ~]# nerdctl load -i busybox.tar
[root@localhost ~]# nerdctl images
REPOSITORY TAG IMAGE ID CREATED PLATFORM SIZE BLOB SIZE
busybox latest f9a104fddb33 1 minutes ago linux/amd64 4.1 MiB 2.1 MiB
busybox_containerd latest f9a104fddb33 3 minutes ago linux/amd64 4.1 MiB 2.1 MiB
history
作用：查看镜像构建时的历史命令层次结构。
示例：
[root@localhost ~]# nerdctl image history busybox
SNAPSHOT
CREATED CREATED BY SIZE COMMENT
sha256:65014c70e84b6817fac42bb201ec5c1ea460a8da246cac0e481f5c9a9491eac0
10 months ago BusyBox 1.37.0 (glibc), Debian 12 4.1 MiB
inspect
作用：查看镜像详细信息。
示例：
[root@localhost ~]# nerdctl image inspect busybox
[
{
"Id":
"sha256:6d3e4188a38af91b0c1577b9e88c53368926b2fe0e1fb985d6e8a70040520c4d",
"RepoTags": [
"busybox:latest"
],
"RepoDigests": [
"busybox@sha256:f9a104fddb33220ec80fc45a4e606c74aadf1ef7a3832eb0b05be9e90cd61f5f
"
],
"Comment": "",
"Created": "2024-09-26T21:31:42Z",
"Author": "",
"Config": {
"AttachStdin": false,
"Env": [
"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
],
"Cmd": [
"sh"
]
},
"Architecture": "amd64",
"Os": "linux",
"Size": 4337664,
"RootFS": {
"Type": "layers",
"Layers": [
"sha256:65014c70e84b6817fac42bb201ec5c1ea460a8da246cac0e481f5c9a9491eac0"
]
},
"Metadata": {
"LastTagTime": "0001-01-01T00:00:00Z"
}
}
]
prune
作用：删除所有未使用的镜像。
示例:
[root@localhost ~]# nerdctl image prune --all --force
[root@localhost ~]# nerdctl image ls
REPOSITORY TAG IMAGE ID CREATED PLATFORM SIZE BLOB SIZE
[root@localhost ~]#
nerdctl 管理容器
帮助信息
[root@localhost ~]# nerdctl container --help
Manage containers
Usage: nerdctl container [flags]
Commands:
commit Create a new image from a container's changes
cp Copy files/folders between a running container and the local filesystem.
create Create a new container. Optionally specify "ipfs://" or "ipns://"
scheme to pull image from IPFS.
exec Run a command in a running container
inspect Display detailed information on one or more containers.
kill Kill one or more running containers
logs Fetch the logs of a container. Expected to be used with 'nerdctl rund'.
ls List containers
pause Pause all processes within one or more containers
port List port mappings or a specific mapping for the container
prune Remove all stopped containers
rename rename a container
restart Restart one or more running containers
rm Remove one or more containers
run Run a command in a new container. Optionally specify "ipfs://" or "ipns://" scheme to pull image from IPFS.
start Start one or more running containers
stop Stop one or more running containers
unpause Unpause all processes within one or more containers
update Update one or more running containers
wait Block until one or more containers stop, then print their exit codes.
Flags:
-h, --help help for container
See also 'nerdctl --help' for the global flags such as '--namespace', '--
snapshotter', and '--cgroup-manager'.
ls
作用：查看容器清单。
示例：
[root@localhost ~]# nerdctl container ls
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
# 可简写为
[root@localhost ~]# nerdctl ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
[root@localhost ~]# nerdctl container ls
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
常用选项：
- -a, --all Show all containers (default shows just running)
- -f, --filter strings Filter matches containers based on given conditions
- –format string Format the output using the given Go template, e.g, ‘{{json .}}’, 'wide
run
作用：创建并运行容器。
示例：
# 语法：
[root@localhost ~]# nerdctl run --help
Run a command in a new container. Optionally specify "ipfs://" or "ipns://"
scheme to pull image from IPFS.
Usage: nerdctl run [flags] IMAGE [COMMAND] [ARG...]
[root@localhost ~]# nerdctl container run -it ubuntu
root@0da9aad32119:/# exit
exit
# 可简写为
[root@localhost ~]# nerdctl run -it ubuntu
# 容器状态为Exited
[root@localhost ~]# nerdctl container ls -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
0da9aad32119 docker.io/library/ubuntu:latest "/bin/bash" 3 minutes ago Exited (130) 2 minutes ago ubuntu-0da9a
常用选项：
- –cpu-shares uint CPU shares (relative weight)
- –cpus float Number of CPUs
- -d, --detach Run container in background and print container ID
- –dns strings Set custom DNS servers
- -e, --env stringArray Set environment variables
- -h, --hostname string Container host name
- -i, --interactive Keep STDIN open even if not attached
- –ip string Pv4 address to assign to the container
- –mac-address string MAC address to assign to the container
- -m, --memory string Memory limit
- –name string Assign a name to the container
- –net strings Connect a container to a network (“bridge”|“host”|“none”|) (default [bridge])
- –network strings Connect a container to a network (“bridge”|“host”|“none”|“container:”|) (default [bridge])
- –privileged Give extended privileges to this container
- –pull string Pull image before running (“always”|“missing”|“never”) (default “missing”)
- –restart string Restart policy to apply when a container exits (implemented values:
“no”|“always|on-failure:n|unless-stopped”) (default “no”) - –rm Automatically remove the container when it exits
- –runtime string Runtime to use for this container, e.g.
- –stop-signal string Signal to stop a container (default “SIGTERM”)
- –stop-timeout Timeout (in seconds) to stop a container
- -t, --tty Allocate a pseudo-TTY
- -v, --volume Bind mount a vo
rm
作用：删除容器。
示例：
[root@localhost ~]# nerdctl container rm 0da9aad32119
0da9aad32119
[root@localhost ~]# nerdctl container ls -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
prune
作用：删除所有未运行的容器。
示例：
[root@localhost ~]# nerdctl container run ubuntu
[root@localhost ~]# nerdctl container run ubuntu
[root@localhost ~]# nerdctl container ls -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
3778651cfacb docker.io/library/ubuntu:latest "/bin/bash" 5 seconds ago Exited (0) 5 seconds ago ubuntu-37786
3e8221845ab4 docker.io/library/ubuntu:latest "/bin/bash" 11 seconds ago Exited (0) 11 seconds ago ubuntu-3e822
[root@localhost ~]# nerdctl container prune --force
Deleted Containers:
3778651cfacba1cd489b065ff7017b272b9edddc71211e2a6e567d9d0ec8ac54
3e8221845ab479f18a091c04443d26632946c9ced264c21a490f6b3052bde0b2
rename
作用：重命名容器。
示例：
[root@localhost ~]# nerdctl container run --name ubuntu-1 ubuntu
[root@localhost ~]# nerdctl container ls -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
61384145427a docker.io/library/ubuntu:latest "/bin/bash" 5 seconds ago Exited (0) 5 seconds ago ubuntu-1
[root@localhost ~]# nerdctl container rename ubuntu-1 ubuntu
[root@localhost ~]# nerdctl container ls -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
61384145427a docker.io/library/ubuntu:latest "/bin/bash" 10 seconds ago Exited (0) 10 seconds ago ubuntu
[root@localhost ~]# nerdctl container rm ubuntu
ubuntu
stop 和 start
作用：停止和启动容器。
示例：
[root@localhost ~]# nerdctl container run -d --name nginx1 nginx
[root@localhost ~]# nerdctl container ls --format "{{.Names}} {{.Status}}"
nginx1 Up
[root@localhost ~]# nerdctl container stop nginx1
nginx1
[root@localhost ~]# nerdctl container ls --format "{{.Names}} {{.Status}}" -a
nginx1 Exited (0) 13 seconds ago
[root@localhost ~]# nerdctl container start nginx1
nginx1
[root@localhost ~]# nerdctl container ls --format "{{.Names}} {{.Status}}"
nginx1 Up
restart
作用：重启容器。
示例：
[root@localhost ~]# nerdctl container restart nginx1
nginx1
pause 和 unpause
作用：暂停和取消挂起容器。
示例：
[root@localhost ~]# nerdctl container pause nginx1
nginx1
[root@localhost ~]# nerdctl container ls --format "{{.Names}} {{.Status}}" -a
nginx1 Paused
[root@localhost ~]# nerdctl container unpause nginx1
nginx1
[root@localhost ~]# nerdctl container ls --format "{{.Names}} {{.Status}}" -a
nginx1 Up
kill
作用：给容器发信号，默认发KILL信号。
示例：
[root@localhost ~]# nerdctl container kill nginx1
945c89b61aafc3475317e8801ad8526fdf337b038bfa315472e4c723bf5406f1
[root@localhost ~]# nerdctl container ls -a --format "{{.Names}} {{.Status}}"
nginx1 Exited (137) 8 seconds ago
exec
作用：在运行的容器内部执行命令。
示例：
[root@localhost ~]# nerdctl container start nginx1
nginx1
[root@localhost ~]# nerdctl container exec -it nginx1 bash
root@945c89b61aaf:/# exit
exit
cp
作用：将宿主机文件复制给容器。
示例：
[root@localhost ~]# nerdctl container cp /etc/hostname nginx1:
[root@localhost ~]# nerdctl container exec nginx1 ls hostname
hostname
inspect
作用：查看容器详细信息。
示例：
[root@localhost ~]# nerdctl container inspect nginx1
[
{
"Id": "945c89b61aafc3475317e8801ad8526fdf337b038bfa315472e4c723bf5406f1",
"Created": "2025-08-02T14:07:36.213384887Z",
"Path": "/docker-entrypoint.sh",
"Args": [
"nginx",
"-g",
"daemon off;"
],
"State": {
"Status": "running",
"Running": true,
"Paused": false,
"Restarting": false,
"Pid": 49359,
"ExitCode": 0,
"Error": "",
"FinishedAt": "0001-01-01T00:00:00Z"
},
"Image": "docker.io/library/nginx:latest",
"ResolvConfPath":
"/var/lib/nerdctl/1935db59/containers/default/945c89b61aafc3475317e8801ad8526fdf337b038bfa315472e4c723bf5406f1/resolv.conf",
"HostnamePath":
"/var/lib/nerdctl/1935db59/containers/default/945c89b61aafc3475317e8801ad8526fdf337b038bfa315472e4c723bf5406f1/hostname",
"LogPath":
"/var/lib/nerdctl/1935db59/containers/default/945c89b61aafc3475317e8801ad8526fdf337b038bfa315472e4c723bf5406f1/945c89b61aafc3475317e8801ad8526fdf337b038bfa315472e4c723bf5406f1-json.log",
"Name": "nginx1",
"RestartCount": 0,
"Driver": "overlayfs",
"Platform": "linux",
"AppArmorProfile": "",
"Mounts": null,
"Config": {
"Hostname": "945c89b61aaf",
"AttachStdin": false,
"Labels": {
"containerd.io/restart.explicitly-stopped": "false",
"io.containerd.image.config.stop-signal": "SIGQUIT",
"nerdctl/extraHosts": "null",
"nerdctl/hostname": "945c89b61aaf",
"nerdctl/log-uri": "binary:///usr/bin/nerdctl?
_NERDCTL_INTERNAL_LOGGING=%2Fvar%2Flib%2Fnerdctl%2F1935db59",
"nerdctl/name": "nginx1",
"nerdctl/namespace": "default",
"nerdctl/networks": "[\"bridge\"]",
"nerdctl/platform": "linux/amd64",
"nerdctl/state-dir":
"/var/lib/nerdctl/1935db59/containers/default/945c89b61aafc3475317e8801ad8526fdf337b038bfa315472e4c723bf5406f1"
}
},
"NetworkSettings": {
"GlobalIPv6Address": "",
"GlobalIPv6PrefixLen": 0,
"IPAddress": "10.4.0.15",
"IPPrefixLen": 24,
"MacAddress": "32:81:21:fb:b4:72",
"Networks": {
"unknown-eth0": {
"IPAddress": "10.4.0.15",
"IPPrefixLen": 24,
"GlobalIPv6Address": "",
"GlobalIPv6PrefixLen": 0,
"MacAddress": "32:81:21:fb:b4:72"
}
}
}
}
]
[root@localhost ~]#
logs
作用：显示容器console终端内容。
示例：
[root@localhost ~]# nerdctl container logs nginx1
/docker-entrypoint.sh: /docker-entrypoint.d/ is not empty, will attempt to perform configuration
/docker-entrypoint.sh: Looking for shell scripts in /docker-entrypoint.d/
/docker-entrypoint.sh: Launching /docker-entrypoint.d/10-listen-on-ipv6-by-default.sh
10-listen-on-ipv6-by-default.sh: info: IPv6 listen already enabled
/docker-entrypoint.sh: Sourcing /docker-entrypoint.d/15-local-resolvers.envsh
/docker-entrypoint.sh: Launching /docker-entrypoint.d/20-envsubst-on-templates.sh
/docker-entrypoint.sh: Launching /docker-entrypoint.d/30-tune-worker-processes.sh
/docker-entrypoint.sh: Configuration complete; ready for start up
2025/08/02 14:10:40 [notice] 1#1: using the "epoll" event method
2025/08/02 14:10:40 [notice] 1#1: nginx/1.29.0
2025/08/02 14:10:40 [notice] 1#1: built by gcc 12.2.0 (Debian 12.2.0-14+deb12u1)
2025/08/02 14:10:40 [notice] 1#1: OS: Linux 4.18.0-553.6.1.el8.x86_64
2025/08/02 14:10:40 [notice] 1#1: getrlimit(RLIMIT_NOFILE): 1024:1024
2025/08/02 14:10:40 [notice] 1#1: start worker processes
2025/08/02 14:10:40 [notice] 1#1: start worker process 22
2025/08/02 14:10:40 [notice] 1#1: start worker process 23
2025/08/02 14:10:40 [notice] 1#1: start worker process 24
2025/08/02 14:10:40 [notice] 1#1: start worker process 25
port
作用：显示宿主机和容器之间端口映射关系。
示例：
[root@localhost ~]# nerdctl container run --name nginx -d -p 8080:80 nginx
2d0923e9f7c816d9fc8f5fa30b1be332c90fff0e354c981b919fc67bd1f97101
[root@localhost ~]# nerdctl container port nginx
80/tcp -> 0.0.0.0:8080
commit
作用：将容器提交为镜像。
示例：
[root@localhost ~]# nerdctl commit nginx nginx_containerd
sha256:6e60d18c9e7f7968f49edfacae16e39df2a995d3119b0b23356fd501cd8348a6
[root@localhost ~]# nerdctl images
REPOSITORY TAG IMAGE ID CREATED PLATFORM
SIZE BLOB SIZE
nginx latest 84ec966e61a8 17 minutes ago linux/amd64
194.4 MiB 68.9 MiB
nginx_containerd latest d59a30a56f7f 3 seconds ago linux/amd64
194.4 MiB 68.9 MiB
ubuntu latest a08e551cb338 26 minutes ago linux/amd64
81.1 MiB 28.4 MiB
nerdctl 管理网络
Containerd 中的网络与Docker类似，所有网络接口默认都是虚拟接口。
当使用nerdctl创建容器时，nerdctl命令会创建一个名称为bridge的Linux网桥（其上有一个nerdctl0内
部接口），利用了Linux虚拟网络技术，在本地主机和容器内分别创建一个虚拟接口，并让它们彼此连通
（这样的一对接口叫做veth pair）。Containerd 默认指定了nerdctl0接口的IP地址和子网掩码，让主机
和容器之间可以通过网桥相互通信。
示例
[root@localhost ~]# nerdctl run -d busybox -- sleep infinity
b721795e02103578656152662f414e88f32191e64976ccafe60c4af10a8fa8c8
[root@localhost ~]# nerdctl container ls
CONTAINER ID IMAGE COMMAND CREATED
STATUS PORTS NAMES
b721795e0210 docker.io/library/busybox:latest "sleep infinity" 12 seconds ago
Up busybox-b7217
[root@localhost ~]# nerdctl exec busybox-b7217 -- ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0@if5: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue
link/ether f6:fc:0b:35:5e:2c brd ff:ff:ff:ff:ff:ff
inet 10.4.0.18/24 brd 10.4.0.255 scope global eth0
valid_lft forever preferred_lft forever
inet6 fe80::f4fc:bff:fe35:5e2c/64 scope link
valid_lft forever preferred_lft forever
[root@localhost ~]#
容器内看到的网卡名：2: eth0@if5，@if5代表对端是5号网卡。
[root@localhost ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default
qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: ens160: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group
default qlen 1000
link/ether 00:0c:29:a7:b8:a7 brd ff:ff:ff:ff:ff:ff
altname enp3s0
inet 192.168.108.30/24 brd 192.168.108.255 scope global noprefixroute ens160
valid_lft forever preferred_lft forever
inet6 fe80::20c:29ff:fea7:b8a7/64 scope link noprefixroute
valid_lft forever preferred_lft forever
3: nerdctl0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP
group default qlen 1000
link/ether 3a:1a:93:b7:ea:d7 brd ff:ff:ff:ff:ff:ff
inet 10.4.0.1/24 brd 10.4.0.255 scope global nerdctl0
valid_lft forever preferred_lft forever
inet6 fe80::381a:93ff:feb7:ead7/64 scope link
valid_lft forever preferred_lft forever
5: veth790d9140@if2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue
master nerdctl0 state UP group default
link/ether 3a:fa:0e:fd:27:5b brd ff:ff:ff:ff:ff:ff link-netnsid 0
inet6 fe80::38fa:eff:fefd:275b/64 scope link
valid_lft forever preferred_lft forever
对应容器主机的网卡：5: veth790d9140@if2，@if2代表对端容器内对应2号网卡。
示例：
[root@localhost ~]# nerdctl network ls
NETWORK ID NAME FILE
17f29b073143 bridge /etc/cni/net.d/nerdctl-bridge.conflist
host
none
[root@localhost ~]# nerdctl network inspect bridge
[
{
"Name": "bridge",
"Id": "17f29b073143d8cd97b5bbe492bdeffec1c5fee55cc1fe2112c8b9335f8b6121",
"IPAM": {
"Config": [
{
"Subnet": "10.4.0.0/24",
"Gateway": "10.4.0.1"
}
]
},
"Labels": {
"nerdctl/default-network": "true"
}
}
]
# 主机中nerdctl0就是容器的网关
[root@localhost ~]# ip addr show nerdctl0
3: nerdctl0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP
group default qlen 1000
link/ether 3a:1a:93:b7:ea:d7 brd ff:ff:ff:ff:ff:ff
inet 10.4.0.1/24 brd 10.4.0.255 scope global nerdctl0
valid_lft forever preferred_lft forever
inet6 fe80::381a:93ff:feb7:ead7/64 scope link
valid_lft forever preferred_lft forever
目前 Containerd 网桥是Linux网桥，用户可以使用brctl show命令查看网桥和端口连接信息。
[root@localhost ~]# brctl show
bridge name bridge id STP enabled interfaces
nerdctl0 8000.3a1a93b7ead7 no veth790d9140
nerdctl network 命令使用帮助
[root@localhost ~]# nerdctl network --help
Manage networks
Usage: nerdctl network [flags]
Commands:
create Create a network
inspect Display detailed information on one or more networks
ls List networks
prune Remove all unused networks
rm Remove one or more networks
Flags:
-h, --help help for network
See also 'nerdctl --help' for the global flags such as '--namespace', '--
snapshotter', and '--cgroup-manager'.
nerdctl 管理存储
nerdctl volume 命令使用帮助
[root@localhost ~]# nerdctl volume --help
Manage volumes
Usage: nerdctl volume [flags]
Commands:
create Create a volume
inspect Display detailed information on one or more volumes
ls List volumes
prune Remove all unused local volumes
rm Remove one or more volumes
Flags:
-h, --help help for volume
See also 'nerdctl --help' for the global flags such as '--namespace', '--
snapshotter', and '--cgroup-manager'.
nerdctl 命令创建容器的时候，可以使用 -v 选项将本地目录挂载给容器实现数据持久化。
示例：
[root@localhost ~]# mkdir /data
[root@localhost ~]# nerdctl run -d -v /data:/data busybox -- sleep infinity
d00a1646169a199e3038851f86b82bff03ac2db6ffd8ea3e875789d2a6d1a000
[root@localhost ~]# touch /data/f1
[root@localhost ~]# nerdctl exec busybox-d00a1 -- ls /data
f1
nerdctl 命令创建容器的时候，也可以使用 -v 选项指定volume。
# 直接写容器目录，会自动生成目录
[root@localhost ~]# nerdctl run -d -v /data busybox -- sleep infinity
29c94622886a219c93b5f6cd1c1ab190f998c66e3b4cbce75437507803b82eea
[root@localhost ~]# nerdctl exec busybox-29c94 -- touch /data/f2
#在/var/lib/nerdctl/xx/volumes/default/xx/_data/f2
#指定宿主机生成的目录名为data
[root@localhost ~]# nerdctl run -d -v data:/data busybox -- sleep infinity
1b1fc00e88471a5abd8787bae438ab8d5ab08f4ec4fa073805407f9fffe2fe73
[root@localhost ~]# nerdctl exec busybox-1b1fc -- touch /data/f3
# 生成data名字的卷
[root@localhost ~]# nerdctl volume ls
VOLUME NAME
DIRECTORY
0c70033c26bcf456d9a0dc3f7dfe723f232e48dee2c8898bf987f8aeebacc1c7
/var/lib/nerdctl/1935db59/volumes/default/0c70033c26bcf456d9a0dc3f7dfe723f232e48d
ee2c8898bf987f8aeebacc1c7/_data
data
/var/lib/nerdctl/1935db59/volumes/default/data/_data
[root@localhost ~]# ls /var/lib/nerdctl/1935db59/volumes/default/0c70033c26bcf456d9a0dc3f7dfe723f232e48dee2c8898bf987f8aeebacc1c7/_data
f2
[root@localhost ~]# ls /var/lib/nerdctl/1935db59/volumes/default/data/_data
f3
nerdctl 管理命名空间
[root@localhost ~]# nerdctl namespace
Unrelated to Linux namespaces and Kubernetes namespaces
Usage: nerdctl namespace [flags]
Aliases: namespace, ns
Commands:
create Create a new namespace
inspect Display detailed information on one or more namespaces.
ls List containerd namespaces
remove Remove one or more namespaces
update Update labels for a namespace
Flags:
-h, --help help for namespace
See also 'nerdctl --help' for the global flags such as '--namespace', '--
snapshotter', and '--cgroup-manager'.
示例：
[root@localhost ~]# nerdctl namespace ls
NAME CONTAINERS IMAGES VOLUMES LABELS
default 10 4 2
八、crictl 实践
crictl 命令介绍
crictl 命令是遵循 CRI 接口规范的一个命令行工具，通常用它来检查和管理kubelet 节点上的容器运行时和镜像。
在kubernetes集群环境中，当我们执行kubectl 命令式，kubelet 代理会自动调用crictl命令管理镜像和容器。
手动执行 crictl 命令时，一般用于查看镜像和容器。
crictl 命令安装
配置kubernetes源：
[root@localhost ~]# vim /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes-new/core/stable/v1.30/rpm/
enabled=1
gpgcheck=1
gpgkey=https://mirrors.aliyun.com/kubernetes-
new/core/stable/v1.30/rpm/repodata/repomd.xml.key
安装CRI命令
[root@localhost ~]# yum install -y cri-tools
crictl 命令配置
使用crictl 命令之前，需要先配置/etc/crictl.yaml 。
示例：配置crictl后端运行时使用containerd。
[root@localhost ~]# vim /etc/crictl.yaml
runtime-endpoint: unix:///run/containerd/containerd.sock
image-endpoint: unix:///run/containerd/containerd.sock
timeout: 5
debug: false
也可以通过命令进行设置：
[root@localhost ~]# crictl config runtime-endpoint unix:///run/containerd/containerd.sock
[root@localhost ~]# crictl config image-endpoint unix:///run/containerd/containerd.sock
更多命令操作，可以直接在命令行输入命令查看帮助。
[root@localhost ~]# crictl config --help
crictl 命令实践
#帮助信息
[root@localhost ~]# crictl
.......
#案列
[root@localhost ~]# crictl pull 054b8ac70e8010d90f2ac00ef29e6580.mirror.swr.myhuaweicloud.com/library/nginx:latest
Image is up to date for
sha256:9f33606b36859ee2db3b761a893fb7c2fc8a13c0fe5f24e304b129f3caf499ad
[root@localhost ~]# crictl images
IMAGE TAG IMAGE ID SIZE
docker.io/library/httpd latest 65005131d37e9 45.2MB
镜像命令
- images, image, img List images
- pull Pull an image from a registry
- inspecti Return the status of one or more images
- imagefsinfo Return image filesystem info
- rmi Remove one or more images
容器命令
- ps List containers
- create Create a new container
- run Run a new container inside a sandbox
- inspect Display the status of one or more containers
- info Display information of the container runtime
- attach Attach to a running container
- exec Run a command in a running container
- logs Fetch the logs of a container
- update Update one or more running containers
- stats List container(s) resource usage statistics
- checkpoint Checkpoint one or more running containers
- start Start one or more created containers
- stop Stop one or more running containers
- rm Remove one or more containers
pod命令
- pods List pods
- runp Run a new pod
- inspectp Display the status of one or more pods
- statsp List pod resource usage statistics
- port-forward Forward local port to a pod
- stopp Stop one or more running pods
- rmp Remove one or more pods
其他命令
- version Display runtime version information
- config Get and set crictl client configuration options
- completion Output shell completion code
- help, h Shows a list of commands or help for one command
命令行对照表
如果您还对Docker比较怀旧的话，执行“alias docker=nerdctl”这样的命令后，您依然可以体验到与Docker相似的感觉。
nerdctl和crictl都是用于管理和操作容器的命令行工具，但是它们在开发者、设计目的和功能上有所不同。
1.nerdctl：
- 开发者：由Docker的创始人之一，也是containerd项目的主要贡献者Akihiro Suda开发。
- 设计目的：nerdctl是一个兼容Docker CLI的containerd CLI，意味着大部分Docker命令可以在nerdctl中运行。
- 功能：它可以管理容器的生命周期，如创建、运行、停止和删除容器。此外，它还支持镜像管理，网络管理，卷管理等。
2.crictl：
- 开发者：由Kubernetes项目社区开发。
- 设计目的：crictl是一个命令行接口，用于与任何实现了Kubernetes容器运行时接口(CRI)的容器运行时进行交互，例如containerd，CRI-O等。
- 功能：它主要用于调试，可以从Kubernetes API Server的角度检查和理解容器运行时的行为。它允许用户直接与容器运行时进行交互，实现容器生命周期管理，镜像管理等。
总的来说，二者主要区别在于他们的使用场景和目标用户并不完全相同。nerdctl更适合需要Docker CLI兼容性的用户，而crictl则更适合需要调试和理解Kubernetes CRI容器运行时行为的用户。
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