容器管理
# 4.1 获取命令帮助
# 4.1.1 获取ctr命令帮助
[root@localhost ~]# ctr --help
NAME:
ctr -
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containerd CLI
USAGE:
ctr [global options] command [command options] [arguments...]
VERSION:
v1.6.0
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
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# 4.1.2 获取创建静态容器命令帮助
# ctr container --help
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
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说明：
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。
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# 4.1.3 获取动态容器命令帮助
# ctr run --help
NAME:
ctr run - run a container
USAGE:
ctr run [command options] [flags] Image|RootFS ID [COMMAND] [ARG...]
OPTIONS:
--rm remove the container after running
--null-io send all IO to /dev/null
--log-uri value log uri
--detach, -d detach from the task after it has started execution
--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:host-uid:length
--gidmap container-gid:host-gid:length run inside a user namespace with the specified GID mapping range; specified with the format container-gid:host-gid: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)
--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
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说明：
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。
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# 4.2 查看容器
container表示静态容器，可用c缩写代表container
# ctr container ls
CONTAINER IMAGE RUNTIME
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或
# ctr c ls
CONTAINER IMAGE RUNTIME
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# 4.3 查看任务
task表示容器里跑的进程, 可用t缩写代表task
# ctr task ls
TASK PID STATUS
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或
# ctr t ls
TASK PID STATUS
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# 4.4 创建静态容器
# ctr c create docker.io/library/nginx:alpine nginx1
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# ctr container ls
CONTAINER IMAGE RUNTIME
nginx1 docker.io/library/nginx:alpine io.containerd.runc.v2
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查看容器详细信息
# ctr container info nginx1
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# 4.5 静态容器启动为动态容器
复制containerd连接runC垫片工具至系统
# ls usr/local/bin/
containerd containerd-shim containerd-shim-runc-v1 containerd-shim-runc-v2 containerd-stress crictl critest ctd-decoder ctr
[root@localhost ~]# cp usr/local/bin/containerd-shim-runc-v2 /usr/bin/
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启动task，即表时在容器中运行了进程，即为动态容器。
# ctr task start -d 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/
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说明：
-d表示daemon或者后台的意思，否则会卡住终端
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查看容器所在宿主机进程，是以宿主机进程的方式存在的。
# ctr task ls
TASK PID STATUS
nginx1 3395 RUNNING
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查看容器的进程(都是物理机的进程)
# ctr task ps nginx1
PID INFO
3395 -
3434 -
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物理机查看到相应的进程
# ps -ef | grep 3395
root 3395 3375 0 19:16 ? 00:00:00 nginx: master process nginx -g daemon off;
101 3434 3395 0 19:16 ? 00:00:00 nginx: worker process
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# 4.6 进入容器操作
# ctr task exec --exec-id 1 nginx1 /bin/sh
ifconfig 查看网卡信息
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
curl 127.0.0.1 访问本地提供的web服务
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
html { color-scheme: light dark; }
body { width: 35em; margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif; }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>
<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>
<p><em>Thank you for using nginx.</em></p>
</body>
</html>
100 615 100 615 0 0 429k 0 --:--:-- --:--:-- --:--:-- 600k
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说明：
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。
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# 4.7 直接运行一个动态容器
# ctr run -d --net-host docker.io/library/nginx:alpine nginx2
/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/
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说明：
* -d 代表dameon，后台运行
* --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)
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查看已运行容器
# ctr container ls
CONTAINER IMAGE RUNTIME
nginx2 docker.io/library/nginx:alpine io.containerd.runc.v2
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查看已运行容器中运行的进程,既tasks
# ctr tasks ls
TASK PID STATUS
nginx2 4061 RUNNING
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进入容器
# ctr task exec --exec-id 1 -t nginx2 /bin/sh
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/ # ifconfig
ens33 Link encap:Ethernet HWaddr 00:0C:29:B1:B6:1D
inet addr:192.168.10.164 Bcast:192.168.10.255 Mask:255.255.255.0
inet6 addr: fe80::2b33:40ed:9311:8812/64 Scope:Link
inet6 addr: fe80::adf4:a8bc:a1c:a9f7/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:55360 errors:0 dropped:0 overruns:0 frame:0
TX packets:30526 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:53511295 (51.0 MiB) TX bytes:2735050 (2.6 MiB)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:68 errors:0 dropped:0 overruns:0 frame:0
TX packets:68 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:5916 (5.7 KiB) TX bytes:5916 (5.7 KiB)
virbr0 Link encap:Ethernet HWaddr 52:54:00:E9:51:82
inet addr:192.168.122.1 Bcast:192.168.122.255 Mask:255.255.255.0
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
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为容器中运行的网站添加网站文件
/ # echo "nginx2" > /usr/share/nginx/html/index.html
/ # exit
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在宿主机上访问网站
[root@localhost ~]# curl 192.168.10.164
nginx2
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# 4.8 暂停容器
查看容器状态
# ctr tasks ls
TASK PID STATUS
nginx2 4061 RUNNING
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暂停容器
# ctr tasks pause nginx2
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再次查看容器状态，看到其状态为PAUSED，表示停止。
# ctr tasks ls
TASK PID STATUS
nginx2 4061 PAUSED
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[root@localhost ~]# curl http://192.168.10.164
在宿主机访问，发现不可以访问到网站
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# 4.9 恢复容器
使用resume命令恢复容器
# ctr tasks resume nginx2
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查看恢复后状态
# ctr tasks ls
TASK PID STATUS
nginx2 4061 RUNNING
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在宿主机上访问容器中提供的服务
# curl http://192.168.10.164
nginx2
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# 4.10 停止容器
# ctr tasks --help
NAME:
ctr tasks - manage tasks
USAGE:
ctr tasks command [command options] [arguments...]
COMMANDS:
attach attach to the IO of a running container
checkpoint checkpoint a container
delete, del, remove, rm delete one or more tasks
exec execute additional processes in an existing container
list, ls list tasks
kill signal a container (default: SIGTERM)
pause pause an existing container
ps list processes for container
resume resume a paused container
start start a container that has been created
metrics, metric get a single data point of metrics for a task with the built-in Linux runtime
OPTIONS:
--help, -h show help
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使用kill命令停止容器中运行的进程，既为停止容器
# ctr tasks kill nginx2
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查看容器停止后状态，STATUS为STOPPED
# ctr tasks ls
TASK PID STATUS
nginx1 3395 RUNNING
nginx2 4061 STOPPED
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# 4.11 删除容器
# ctr tasks delete nginx2
必须先停止tasks或先删除task，再删除容器
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查看静态容器，确认其还存在于系统中
# ctr container ls
CONTAINER IMAGE RUNTIME
nginx2 docker.io/library/nginx:alpine io.containerd.runc.v2
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删除容器
# ctr container delete nginx2
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