# 安装
yum install -y yum-utils
yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
yum makecache fast
yum -y install containerd.io
注意：yum方式安装，默认已安装libseccomp，runc
rpm -qa | grep containerd
systemctl enable containerd
systemctl start containerd
systemctl status containerd
ctr version
# 生成默认模块配置文件
containerd config default > /etc/containerd/config.toml
sandbox_image = "docker.io/liuxincuit/pause:3.6" 由于网络原因，此处被替换
sandbox_image = "liuxincuit/pause:3.6" 由于网络原因，此处被替换
[plugins."io.containerd.grpc.v1.cri".cni] =》网络插件尚未安装
bin_dir = "/opt/cni/bin"
conf_dir = "/etc/cni/net.d"
conf_template = ""
ip_pref = ""
max_conf_num = 1
添加其他镜像仓库
[plugins."io.containerd.grpc.v1.cri".registry.mirrors]
[plugins."io.containerd.grpc.v1.cri".registry.mirrors."docker.io"]
endpoint = ["https://docker.mirrors.ustc.edu.cn","http://hub-mirror.c.163.com"]
[plugins."io.containerd.grpc.v1.cri".registry.mirrors."gcr.io"]
endpoint = ["https://gcr.mirrors.ustc.edu.cn"]
[plugins."io.containerd.grpc.v1.cri".registry.mirrors."k8s.gcr.io"]
endpoint = ["https://gcr.mirrors.ustc.edu.cn/google-containers/"]
[plugins."io.containerd.grpc.v1.cri".registry.mirrors."quay.io"]
endpoint = ["https://quay.mirrors.ustc.edu.cn"]
# 查看runc
runc -v
# 常用命令
ctr --help
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
ctr images ls
ctr images pull docker.io/library/nginx:alpine
注意：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，可以这样理解，使用dockerfile文件构建镜像，使用containerd来管理容器
ctr images mount docker.io/library/nginx:alpine /mnt
umount /mnt
ctr images export --all-platforms nginx.img docker.io/library/nginx:alpine
ctr images rm docker.io/library/nginx:alpine
ctr images import nginx.img
ctr images tag docker.io/library/nginx:alpine nginx:alpine
ctr images check
注意：
1.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。
2.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。
ctr container ls =》 ctr c ls
ctr task ls =》 ctr t ls
ctr container create docker.io/library/nginx:alpine nginx1
ctr container info nginx1
ctr task start -d nginx1
# ctr task ps nginx1 (查看容器的进程(都是物理机的进程)) => 第一个pid是父进程ID，从下面的进程中可以看出
PID INFO
1591 -
1629 -
1630 -
1631 -
1632 -
# ps -ef|grep 1591
root 1591 1571 0 09:42 ? 00:00:00 nginx: master process nginx -g daemon off;
101 1629 1591 0 09:42 ? 00:00:00 nginx: worker process
101 1630 1591 0 09:42 ? 00:00:00 nginx: worker process
101 1631 1591 0 09:42 ? 00:00:00 nginx: worker process
101 1632 1591 0 09:42 ? 00:00:00 nginx: worker process
ctr task exec --exec-id 1 nginx1 /bin/sh => 没有命令提示符，--exec-id为exec进程设定一个id，可以随意输入，只要保证唯一即可
查看网卡信息，默认只有一个lo本地回环网卡
使用exit退出容器
注意：加上参数-t可以显示命令提示符：/# (前面的/表示的是当前所在路径)
ctr run -d --net-host docker.io/library/nginx:alpine 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)
ctr task exec --exec-id 2 -t nginx2 /bin/sh => 有命令提示符，
查看网卡信息，除了只有一个lo本地回环网卡，还有宿主机网卡
ctr task pause nginx2
ctr task resume nginx2
ctr task kill nginx2
ctr task delete nginx2
ctr container delete nginx2
注意：使用-d参数启动的容器，task kill不掉，可以先用系统kill命令杀手pid，然后再task delete，container delete
# 添加harbor作为个人私有仓库
[plugins."io.containerd.grpc.v1.cri".registry.mirrors]
[plugins."io.containerd.grpc.v1.cri".registry.mirrors."docker.io"]
endpoint = ["https://docker.mirrors.ustc.edu.cn","http://hub-mirror.c.163.com"]
[plugins."io.containerd.grpc.v1.cri".registry.mirrors."gcr.io"]
endpoint = ["https://gcr.mirrors.ustc.edu.cn"]
[plugins."io.containerd.grpc.v1.cri".registry.mirrors."k8s.gcr.io"]
endpoint = ["https://gcr.mirrors.ustc.edu.cn/google-containers/"]
[plugins."io.containerd.grpc.v1.cri".registry.mirrors."quay.io"]
endpoint = ["https://quay.mirrors.ustc.edu.cn"]
[plugins."io.containerd.grpc.v1.cri".registry.mirrors."www.myharbor.com"]
endpoint = ["https://www.myharbor.com/"]
[plugins."io.containerd.grpc.v1.cri".registry.configs]
[plugins."io.containerd.grpc.v1.cri".registry.configs."www.myharbor.com".tls]
#insecure_skip_verify = true
insecure_skip_verify = false
ca_file = "/etc/containerd/www.myharbor.com/ca.crt"
cert_file = "/etc/containerd/www.myharbor.com/www.myharbor.com.crt"
key_file = "/etc/containerd/www.myharbor.com/www.myharbor.com.key"
[plugins."io.containerd.grpc.v1.cri".registry.configs."www.myharbor.com".auth]
username = "test"
password = "Test123456"
但是用ctl拉取镜像的时候有报错：
# ctr images pull www.myharbor.com/library/busybox:v0.1
INFO[0000] trying next host error="failed to do request: Head \"https://www.myharbor.com/v2/library/busybox/manifests/v0.1\": x509: certificate signed by unknown authority" host=www.myharbor.com
ctr: failed to resolve reference "www.myharbor.com/library/busybox:v0.1": failed to do request: Head "https://www.myharbor.com/v2/library/busybox/manifests/v0.1": x509: certificate signed by unknown authority
[root@localhost ~]# ctr images pull www.myharbor.com/mytest/busybox:v0.1
INFO[0000] trying next host error="failed to do request: Head \"https://www.myharbor.com/v2/mytest/busybox/manifests/v0.1\": x509: certificate signed by unknown authority" host=www.myharbor.com
ctr: failed to resolve reference "www.myharbor.com/mytest/busybox:v0.1": failed to do request: Head "https://www.myharbor.com/v2/mytest/busybox/manifests/v0.1": x509: certificate signed by unknown authority
解决办法：；拉取镜像的命令中写上用户名和密码，以及ca证书等
ctr images pull --help
OPTIONS:
--skip-verify, -k skip SSL certificate validation
--plain-http allow connections using plain HTTP
--user value, -u value user[:password] Registry user and password
--refresh value refresh token for authorization server
--hosts-dir value Custom hosts configuration directory
--tlscacert value path to TLS root CA
--tlscert value path to TLS client certificate
--tlskey value path to TLS client key
--http-dump dump all HTTP request/responses when interacting with container registry
--http-trace enable HTTP tracing for registry interactions
--snapshotter value snapshotter name. Empty value stands for the default value. [$CONTAINERD_SNAPSHOTTER]
--label value labels to attach to the image
--platform value Pull content from a specific platform
--all-platforms pull content and metadata from all platforms
--all-metadata Pull metadata for all platforms
--print-chainid Print the resulting image's chain ID
--max-concurrent-downloads value Set the max concurrent downloads for each pull (default: 0)
ctr images pull --user test:Test123456 --tlscacert /etc/containerd/www.myharbor.com/ca.crt www.myharbor.com/mytest/busybox:v0.2
ctr images tag www.myharbor.com/mytest/busybox:v0.2 www.myharbor.com/mytest/busybox:v0.3
ctr images push --user test:Test123456 --tlscacert /etc/containerd/www.myharbor.com/ca.crt www.myharbor.com/mytest/busybox:v0.3
ctr namespace --help
COMMANDS:
create, c create a new namespace
list, ls list namespaces
remove, rm remove one or more namespaces
label set and clear labels for a namespace
OPTIONS:
--help, -h show help
ctr namespace ls
ctr namespace create kubemsb
ctr -n kubemsb tasks ls
ctr -n kubemsb images pull docker.io/library/nginx:latest =》指定空间拉取的镜像只能在该命名空间内看到
ctr -n kubemsb container create docker.io/library/nginx:latest nginxapp
ctr -n kubemsb container ls
ctr -n kubemsb images ls => 能看到镜像
ctr -n defalut images ls => 看不到镜像
ctr images ls => 看不到镜像
yum方式安装的，默认Containerd管理的容器仅有lo网络，无法访问容器之外的网络，可以为其添加网络插件，使用容器可以连接外网。
https://github.com/containernetworking/cni
https://github.com/containernetworking/plugins
Containerd配置文件中默认有如下关于cni的配置
[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
下载cni工具源码包：cni-1.1.1.tar.gz
下载cni插件工具源码包：cni-plugins-linux-amd64-v1.1.1.tgz
tar xf cni-1.1.1.tar.gz && mv cni-1.1.1 cni
mkdir -p /opt/cni/bin ==》 跟上面配置文件的保持一致
tar xf cni-plugins-linux-amd64-v1.1.1.tgz -C /opt/cni/bin
创建名为mynet的网络，其中包含名为cni0的网桥
$ cat >/etc/cni/net.d/10-mynet.conf <<EOF
{
"cniVersion": "1.0.0",
"name": "mynet",
"type": "bridge",
"bridge": "cni0",
"isGateway": true,
"ipMasq": true,
"ipam": {
"type": "host-local",
"subnet": "10.22.0.0/16",
"routes": [
{ "dst": "0.0.0.0/0" }
]
}
}
EOF
$ cat >/etc/cni/net.d/99-loopback.conf <<EOF
{
"cniVersion": "1.0.0",
"name": "lo",
"type": "loopback"
}
EOF
注意：上面俩文件的cniVersion不能写1.1.1，有限制
mynet : error executing ADD: {
"code": 1,
"msg": "incompatible CNI versions",
"details": "config is \"1.1.1\", plugin supports [\"0.1.0\" \"0.2.0\" \"0.3.0\" \"0.3.1\" \"0.4.0\" \"1.0.0\"]"
}
yum install epel-release -y && yum -y install jq
cd cni/scripts/
执行脚本文件，基于/etc/cni/net.d/目录中的*.conf配置文件生成容器网络
CNI_PATH=/opt/cni/bin ./priv-net-run.sh echo "Hello World"
3: cni0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
link/ether 52:23:71:8e:90:01 brd ff:ff:ff:ff:ff:ff
inet 10.22.0.1/16 brd 10.22.255.255 scope global cni0
valid_lft forever preferred_lft forever
inet6 fe80::5023:71ff:fe8e:9001/64 scope link
valid_lft forever preferred_lft forever
# ip route
10.22.0.0/16 dev cni0 proto kernel scope link src 10.22.0.1
ctr images pull docker.io/library/busybox:latest busybox
ctr run -d docker.io/library/busybox:latest busybox
# ctr tasks exec --exec-id $RANDOM -t busybox /bin/sh
/ # ip addr
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
pid=(ctr tasks ls | grep busybox | awk '{print $2}')
echo $pid
netnspath=/proc/$pid/ns/net
echo $netnspath
cd cni/scripts/
CNI_PATH=/opt/cni/bin ./exec-plugins.sh add $pid $netnspath
# ctr tasks exec --exec-id $RANDOM -t busybox /bin/sh =》进入容器确认是否添加网卡信息
/ # ip addr
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 6e:66:b7:e1:8e:54 brd ff:ff:ff:ff:ff:ff
inet 10.22.0.3/16 brd 10.22.255.255 scope global eth0
valid_lft forever preferred_lft forever
inet6 fe80::6c66:b7ff:fee1:8e54/64 scope link
valid_lft forever preferred_lft forever
在容器中ping容器宿主机IP地址 => 通
在容器中ping宿主机所在网络的网关IP地址 => 通
在容器中ping宿主机所在网络中的其它主机IP地址 => 通
/ # ping -c 3 www.baidu.com
ping: bad address 'www.baidu.com'
宿主机跟容器网路互通，但是容器无法访问外网
把宿主机目录挂载至Containerd容器中，实现容器数据持久化存储
ctr container create docker.io/library/busybox:latest busybox3 --mount type=bind,src=/tmp,dst=/hostdir,options=rbind:rw
Docker集成Containerd实现容器管理，修改Docker服务文件，以便使用已安装的containerd
# cat /usr/lib/systemd/system/docker.service
[Unit]
Description=Docker Application Container Engine
Documentation=https://docs.docker.com
After=network-online.target docker.socket firewalld.service containerd.service
Wants=network-online.target
Requires=docker.socket containerd.service
[Service]
Type=notify
#ExecStart=/usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock # 这行是原先的
ExecStart=/usr/bin/dockerd --containerd /run/containerd/containerd.sock --debug # 这行是修改后的
ExecReload=/bin/kill -s HUP $MAINPID
TimeoutSec=0
RestartSec=2
Restart=always
StartLimitBurst=3
StartLimitInterval=60s
LimitNOFILE=infinity
LimitNPROC=infinity
LimitCORE=infinity
TasksMax=infinity
Delegate=yes
KillMode=process
OOMScoreAdjust=-500
[Install]
WantedBy=multi-user.target
systemctl daemon-reload && systemctl restart docker
使用docker命令启动一个容器后，再使用ctr查看是否添加一个新的namespace，本案例中发现添加一个moby命名空间，即为docker使用的命名空间。
ctr namespace ls
查看moby命名空间，发现使用docker run运行的容器包含在其中
ctr -n moby container ls
使用ctr能够查看到一个正在运行的容器，既表示docker run运行的容器是被containerd管理的。
使用docker stop停止且使用docker rm删除容器后再观察，发现容器被删除。
ctr -n moby container ls && ctr -n moby tasks ls
containerd使用总结的相关教程结束。
