CoreOS 容器 Rkt 简单介绍

由于 Docker 已经成为事实上的容器老大,这里暂且将 rkt 内容放入 docker 文件夹。哈哈

官方网站:https://coreos.com/rkt/

官方文档:https://coreos.com/rkt/docs/latest/

GitHub:https://github.com/rkt/rkt/

这里使用 CoreOS 来学习 Rkt,其他 Linux 系统上 Rkt 的安装方法很简单,这里不再赘述。

Rkt 目前只支持 Linux 系统。

先看一下命令列表

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
NAME:
rkt - rkt, the application container runner

USAGE:
rkt [command]

VERSION:
1.29.0

COMMANDS:
api-service Run API service (experimental)
cat-manifest Inspect and print the pod manifest
completion Output shell completion code for the specified shell
config Print configuration for each stage in JSON format
enter Enter the namespaces of an app within a rkt pod
export Export an app from an exited pod to an ACI file
fetch Fetch image(s) and store them in the local store
gc Garbage collect rkt pods no longer in use
image cat-manifest Inspect and print the image manifest
image export Export a stored image to an ACI file
image extract Extract a stored image to a directory
image gc Garbage collect local store
image list List images in the local store
image render Render a stored image to a directory with all its dependencies
image rm Remove one or more images with the given IDs or image names from the local store
image verify Verify one or more rendered images in the local store
list List pods
metadata-service Run metadata service
prepare Prepare to run image(s) in a pod in rkt
rm Remove all files and resources associated with an exited pod
run Run image(s) in a pod in rkt
run-prepared Run a prepared application pod in rkt
status Check the status of a rkt pod
stop Stop a pod
trust Trust a key for image verification
version Print the version and exit
help Help about any command

DESCRIPTION:
A CLI for running app containers on Linux.

To get the help on any specific command, run "rkt help command".

OPTIONS:
--debug[=false] print out more debug information to stderr
--dir=/var/lib/rkt rkt data directory
--insecure-options=none comma-separated list of security features to disable. Allowed values: "none", "image", "tls", "ondisk", "http", "pubkey", "capabilities", "paths", "seccomp", "all-fetch", "all-run", "all"
--local-config=/etc/rkt `local` configuration directory
--system-config=/usr/lib/rkt system configuration directory
--trust-keys-from-https[=false] automatically trust gpg keys fetched from https
--user-config= user configuration directory

rkt 使用的是 pod 的概念,与 k8s 联系紧密,可能对应 docker 中的容器概念。

下载 Docker 镜像

rktdocker 多了一个验证的功能,下载 Docker 镜像必须加上不要验证的参数。

1
2
3
$ rkt fetch --insecure-options=image docker://ubuntu

# fetch 与 git 中的 fetch 含义差不多,对应 docker pull

查看镜像

1
2
3
4
5
6
$ rkt image list

ID NAME SIZE IMPORT TIME LAST USED
sha512-bea6e5210d47 registry-1.docker.io/library/ubuntu:latest 98MiB 1 minute ago 1 minute ago

# 与 docker 中的命令一致,可能遵循了某种标准。哈哈,别和我说 docker images 那是旧命令了,好吧!

运行一个 pod

1
2
3
4
5
6
7
8
$ sudo rkt --insecure-options=image \
run \
--interactive \
docker://ubuntu

# docker run XXX

$ rkt run --help

--interactive 与 docker -it 对应

--volume data,kind=host,source=/srv/data,readOnly=false 挂载文件

--volume data,kind=empty,readOnly=false

--mount volume=VOL,target=PATH

1
2
3
4
5
6
7
$ sudo rkt --insecure-options=image \
run \
--interactive \
--volume data,kind=host,source=/srv/data \
--mount volume=data,target=/srv/data \
docker://ubuntu \
--exec /bin/sh

--port=80-tcp:80 暴露端口

1
2
3
4
$ sudo rkt --insecure-options=image \
run \
docker://nginx:alpine \
--port=80-tcp:80

--set-env=KEY=VALUE 设置 pod 环境变量

--environment=foo=bar 设置 pod 环境变量

--exec /bin/sh

--name=name

--net=host | default | none

--net="net1:IP=1.2.3.4"

后台运行

systemd-run

https://coreos.com/rkt/docs/latest/using-rkt-with-systemd.html#systemd-run

1
2
3
4
5
6
7
$ sudo systemd-run \
--slice=machine \
rkt \
--insecure-options=image \
run \
--net=host \
docker://nginx:alpine

daemon

http://www.libslack.org/daemon/

查看 pods 信息

1
2
3
4
5
$ rkt list
UUID APP IMAGE NAME STATE CREATED STARTED NETWORKS
ea4b9fe5 nginx registry-1.docker.io/library/nginx:alpine running 9 seconds ago 9 seconds ago default:ip4=172.16.28.5

# docker ps -a

进入 pod

1
2
3
$ sudo rkt enter ea sh

# docker exec

停止 pod

1
2
3
$ sudo rkt stop ea

# docker stop

删除 pod

1
2
3
$ sudo rkt rm ea

# docker rm

More information

khs1994 wechat
微信扫码赞赏我的文章
0%