集群镜像插件使用

插件类型列表

主机名插件

主机名插件将帮助您更改所有主机名

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
---
apiVersion: sealer.aliyun.com/v1alpha1
kind: Plugin
metadata:
  name: MyHostname # 指定插件名称，将会转储到$rootfs/plugins目录下。
spec:
  type: HOSTNAME #插件类型
  action: PreInit # 指定运行阶段
  data: |
    192.168.0.2 master-0
    192.168.0.3 master-1
    192.168.0.4 master-2
    192.168.0.5 node-0
    192.168.0.6 node-1
    192.168.0.7 node-2

脚本插件

你可以在指定节点的任何阶段执行任何shell命令。

1
2
3
4
5
6
7
8
9
10
apiVersion: sealer.aliyun.com/v1alpha1
kind: Plugin
metadata:
  name: MyShell
spec:
  type: SHELL
  action: PostInstall # # 指定运行阶段【PreInit ｜ PreInstall ｜ PostInstall ｜ PostClean】
  on: node-role.kubernetes.io/master=
  data: |
    kubectl get nodes
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
action : [PreInit| PreInstall| PostInstall] # 指定执行shell的时机
  镜像挂载前阶段          |   action: Originally
  在初始化之前之前执行命令  |  action: PreInit
  在添加节点之前执行命令    |  action: PreJoin
  在添加节点之后执行命令    |  action: PostJoin
  在安装集群之前执行命令    |  action: PreInstall
  在安装集群之后执行命令    |  action: PostInstall
  在清理集群后执行命令      |  action: PostClean
  组合使用                | action: PreInit|PreJoin
on     : #指定执行命令的机器
  为空时默认在所有节点执行
  在所有master节点上执行  on: master
  在所有node节点上执行    on: node
  在指定IP上执行         on: 192.168.56.113,192.168.56.114,192.168.56.115,192.168.56.116
  在有连续IP的机器上执行   on: 192.168.56.113-192.168.56.116
  在指定label节点上执行(action需设置为PostInstall)    on: node-role.kubernetes.io/master=
data   : #指定执行的shell命令

标签插件

帮助您在安装kubernetes集群后设置标签

1
2
3
4
5
6
7
8
9
10
11
12
13
14
apiVersion: sealer.aliyun.com/v1alpha1
kind: Plugin
metadata:
  name: MyLabel
spec:
  type: LABEL
  action: PostInstall
  data: |
    192.168.0.2 ssd=true
    192.168.0.3 ssd=true
    192.168.0.4 ssd=true
    192.168.0.5 ssd=false,hdd=true
    192.168.0.6 ssd=false,hdd=true
    192.168.0.7 ssd=false,hdd=true

集群检测插件

由于服务器以及环境因素(服务器磁盘性能差)可能会导致sealer安装完kubernetes集群后，立即部署应用服务，出现部署失败的情况。cluster check插件会等待kubernetes集群稳定后再部署应用服务。

1
2
3
4
5
6
7
apiVersion: sealer.aliyun.com/v1alpha1
kind: Plugin
metadata:
  name: checkCluster
spec:
  type: CLUSTERCHECK
  action: PreGuest

污点插件

如果你在Clusterfile后添加taint插件配置并应用它，sealer将帮助你添加污点和去污点：

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
apiVersion: sealer.aliyun.com/v1alpha1
kind: Plugin
metadata:
  name: taint
spec:
  type: Taint
  action: PreGuest
  data: |
    192.168.56.3 key1=value1:NoSchedule
    192.168.56.4 key2=value2:NoSchedule-
    192.168.56.3-192.168.56.7 key3:NoSchedule
    192.168.56.3,192.168.56.4,192.168.56.5,192.168.56.6,192.168.56.7 key4:NoSchedule
    192.168.56.3 key5=:NoSchedule
    192.168.56.3 key6:NoSchedule-
    192.168.56.4 key7:NoSchedule-

data写法为ips taint_argument
ips : 多个ip通过,连接，连续ip写法为 首ip-末尾ip
taint_argument: 同kubernetes 添加或去污点写法(key=value:effect #effect必须为：NoSchedule, PreferNoSchedule 或 NoExecute)。

Etcd 备份插件

1
2
3
4
5
6
7
apiVersion: sealer.aliyun.com/v1alpha1
kind: Plugin
metadata:
  name: MyBackup
spec:
  type: ETCD
  action: PostInstall

Out of tree plugin

at present, we only support the golang so file as out of tree plugin. More description about golang plugin
see golang plugin website.

copy the so file and the plugin config to your cloud image at build stage use Kubefile,sealer will parse and execute
it. develop your own out of tree plugin see sealer plugin.

plugin config:

1
2
3
4
5
6
7
8
9
apiVersion: sealer.aliyun.com/v1alpha1
kind: Plugin
metadata:
  name: label_nodes.so # out of tree plugin name
spec:
  type: LABEL_TEST_SO # define your own plugin type.
  action: PostInstall # which stage will this plugin be applied.
  data: |
    192.168.0.2 ssd=true

Kubefile:

script
1
2
3
FROM kubernetes:v1.19.8
COPY label_nodes.so plugin
COPY label_nodes.yaml plugin

Build a cluster image that contains the golang plugin (or more plugins):

script
1
sealer build -m lite -t kubernetes-post-install:v1.19.8 .

如何使用插件

通过Clusterfile使用插件

例如，在安装kubernetes集群后设置节点标签:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
apiVersion: sealer.cloud/v2
kind: Cluster
metadata:
  name: default-kubernetes-cluster
spec:
  image: kubernetes:v1.19.8
  ssh:
    passwd: xxx
  hosts:
    - ips: [ 192.168.0.2,192.168.0.3,192.168.0.4 ]
      roles: [ master ]
    - ips: [ 192.168.0.5 ]
      roles: [ node ]
---
apiVersion: sealer.aliyun.com/v1alpha1
kind: Plugin
metadata:
  name: LABEL
spec:
  type: LABEL
  action: PostInstall
  data: |
    172.20.126.8 ssd=false,hdd=true
script
1
sealer apply -f Clusterfile

在Kubefile中使用默认插件

在很多情况下，可以不使用Clusterfile而使用插件，本质上是在使用插件之前存储了Clusterfile插件到$rootfs/plugins目录下 所以当我们构建镜像时可以添加自定义默认插件。

插件配置文件 shell.yaml:

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
apiVersion: sealer.aliyun.com/v1alpha1
kind: Plugin
metadata:
name: taint
spec:
type: SHELL
action: PostInstall
on: node-role.kubernetes.io/master=
data: |
  kubectl get nodes
---
apiVersion: sealer.aliyun.com/v1alpha1
kind: Plugin
metadata:
  name: SHELL
spec:
  action: PostInstall
  data: |
    if type yum >/dev/null 2>&1;then
    yum -y install iscsi-initiator-utils
    systemctl enable iscsid
    systemctl start iscsid
    elif type apt-get >/dev/null 2>&1;then
    apt-get update
    apt-get -y install open-iscsi
    systemctl enable iscsid
    systemctl start iscsid
    fi

Kubefile:

script
1
2
FROM kubernetes:v1.19.8
COPY shell.yaml plugin

构建一个包含安装iscsi的插件(或更多插件)的集群镜像:

script
1
sealer build -m lite -t kubernetes-iscsi:v1.19.8 .

通过镜像启动集群后插件也将被执行，而无需在Clusterfile中定义插件:
sealer run kubernetes-iscsi:v1.19.8 -m x.x.x.x -p xxx