k8s1.14-helm基本使用

发表于 | 分类于 | 浏览 次

仓库

Helm 的 Repo 仓库和 Docker Registry 比较类似，Chart 库可以用来存储和共享打包 Chart 的位置，我们在安装了 Helm 后，默认的仓库地址是 google 的一个地址，这对于我们不能科学上网的同学就比较苦恼了，没办法访问到官方提供的 Chart 仓库，可以用helm repo list来查看当前的仓库配置：

1
2
3
4
helm repo list
NAME    URL
stable  https://kubernetes-charts.storage.googleapis.com/
local   http://127.0.0.1:8879/charts

替换阿里的仓库：

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
[root@master101 sy]# helm repo remove stable
"stable" has been removed from your repositories



[root@master101 sy]# helm repo list         
NAME    URL                         
local   http://127.0.0.1:8879/charts


[root@master101 sy]# helm repo add stable https://kubernetes.oss-cn-hangzhou.aliyuncs.com/charts
"stable" has been added to your repositories
[root@master101 sy]# helm repo update       
Hang tight while we grab the latest from your chart repositories...
...Skip local chart repository
...Successfully got an update from the "stable" chart repository
Update Complete.
[root@master101 sy]# helm repo list
NAME    URL                                                   
local   http://127.0.0.1:8879/charts                          
stable  https://kubernetes.oss-cn-hangzhou.aliyuncs.com/charts

仓库添加完成后，可以使用 update 命令进行仓库更新。当然如果要我们自己来创建一个 web 服务器来服务 Helm Chart 的话，只需要实现下面几个功能点就可以提供服务了：

  • 将索引和Chart置于服务器目录中
  • 确保索引文件index.yaml可以在没有认证要求的情况下访问
  • 确保 yaml 文件的正确内容类型（text/yaml 或 text/x-yaml）

查找 chart

Helm 将 Charts 包安装到 Kubernetes 集群中，一个安装实例就是一个新的 Release，要找到新的 Chart，我们可以通过搜索命令完成。

直接运行helm search命令可以查看有哪些 Charts 是可用的： 

1
2
3
4
5
6
7
8
9
10
11
12
13
[root@master101 sy]# helm search
NAME                            CHART VERSION   APP VERSION     DESCRIPTION                                                 
stable/acs-engine-autoscaler    2.1.3           2.1.1           Scales worker nodes within agent pools                      
stable/aerospike                0.1.7           v3.14.1.2       A Helm chart for Aerospike in Kubernetes                    
stable/anchore-engine           0.1.3           0.1.6           Anchore container analysis and policy evaluation engine s...
stable/artifactory              7.0.3           5.8.4           Universal Repository Manager supporting all major packagi...
stable/artifactory-ha           0.1.0           5.8.4           Universal Repository Manager supporting all major packagi...
stable/aws-cluster-autoscaler   0.3.2                           Scales worker nodes within autoscaling groups.              
stable/bitcoind                 0.1.0           0.15.1          Bitcoin is an innovative payment network and a new kind o...
stable/buildkite                0.2.1           3               Agent for Buildkite                                         
stable/centrifugo               2.0.0           1.7.3           Centrifugo is a real-time messaging server.                 
stable/cert-manager             0.2.2           0.2.3           A Helm chart for cert-manager                               
stable/chaoskube                0.6.2           0.6.1           Chaoskube periodically kills random pods in your Kubernet...

搜索mysql：

1
2
3
4
5
6
7
[root@master101 sy]# helm search mysql
NAME                            CHART VERSION   APP VERSION     DESCRIPTION                                                 
stable/mysql                    0.3.5                           Fast, reliable, scalable, and easy to use open-source rel...
stable/percona                  0.3.0                           free, fully compatible, enhanced, open source drop-in rep...
stable/percona-xtradb-cluster   0.0.2           5.7.19          free, fully compatible, enhanced, open source drop-in rep...
stable/gcloud-sqlproxy          0.2.3                           Google Cloud SQL Proxy                                      
stable/mariadb                  2.1.6           10.1.31         Fast, reliable, scalable, and easy to use open-source rel...

inspect 命令来查看一个 chart 的详细信息： 

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
[root@master101 sy]# helm inspect  stable/mysql
description: Fast, reliable, scalable, and easy to use open-source relational database
  system.
engine: gotpl
home: https://www.mysql.com/
icon: https://www.mysql.com/common/logos/logo-mysql-170x115.png
keywords:
- mysql
- database
- sql
maintainers:
- email: viglesias@google.com
  name: Vic Iglesias
name: mysql
sources:
- https://github.com/kubernetes/charts
- https://github.com/docker-library/mysql
version: 0.3.5

---
## mysql image version
## ref: https://hub.docker.com/r/library/mysql/tags/
##
image: "mysql"
imageTag: "5.7.14"

## Specify password for root user
##
## Default: random 10 character string
# mysqlRootPassword: testing

## Create a database user
##
# mysqlUser:
# mysqlPassword:

## Allow unauthenticated access, uncomment to enable
##
# mysqlAllowEmptyPassword: true

## Create a database
##
# mysqlDatabase:

安装 chart

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
52
53
54
55
56
57
58
59
60
61
helm install stable/mysql
NAME:   mewing-squid
LAST DEPLOYED: Tue Sep  4 23:31:23 2018
NAMESPACE: default
STATUS: DEPLOYED

RESOURCES:
==> v1/PersistentVolumeClaim
NAME                STATUS   VOLUME  CAPACITY  ACCESS MODES  STORAGECLASS  AGE
mewing-squid-mysql  Pending  1s

==> v1/Service
NAME                TYPE       CLUSTER-IP     EXTERNAL-IP  PORT(S)   AGE
mewing-squid-mysql  ClusterIP  10.108.197.48  <none>       3306/TCP  1s

==> v1beta1/Deployment
NAME                DESIRED  CURRENT  UP-TO-DATE  AVAILABLE  AGE
mewing-squid-mysql  1        0        0           0          1s

==> v1/Pod(related)
NAME                                 READY  STATUS   RESTARTS  AGE
mewing-squid-mysql-69f587bdf9-z7glv  0/1    Pending  0         0s

==> v1/Secret
NAME                TYPE    DATA  AGE
mewing-squid-mysql  Opaque  2     1s

==> v1/ConfigMap
NAME                     DATA  AGE
mewing-squid-mysql-test  1     1s


NOTES:
MySQL can be accessed via port 3306 on the following DNS name from within your cluster:
mewing-squid-mysql.default.svc.cluster.local

To get your root password run:

    MYSQL_ROOT_PASSWORD=$(kubectl get secret --namespace default mewing-squid-mysql -o jsonpath="{.data.mysql-root-password}" | base64 --decode; echo)

To connect to your database:

1. Run an Ubuntu pod that you can use as a client:

    kubectl run -i --tty ubuntu --image=ubuntu:16.04 --restart=Never -- bash -il

2. Install the mysql client:

    $ apt-get update && apt-get install mysql-client -y

3. Connect using the mysql cli, then provide your password:
    $ mysql -h mewing-squid-mysql -p

To connect to your database directly from outside the K8s cluster:
    MYSQL_HOST=127.0.0.1
    MYSQL_PORT=3306

    # Execute the following command to route the connection:
    kubectl port-forward svc/mewing-squid-mysql 3306

    mysql -h ${MYSQL_HOST} -P${MYSQL_PORT} -u root -p${MYSQL_ROOT_PASSWORD}

--name参数指定 名字：

1
helm install stable/mysql --name mydb

自定义 chart

要查看 chart 上可配置的选项，使用helm inspect values命令即可，比如我们这里查看上面的 mysql 的配置选项： 

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
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
[root@master101 sy]#  helm inspect values stable/mysql
## mysql image version
## ref: https://hub.docker.com/r/library/mysql/tags/
##
image: "mysql"
imageTag: "5.7.14"

## Specify password for root user
##
## Default: random 10 character string
# mysqlRootPassword: testing

## Create a database user
##
# mysqlUser:
# mysqlPassword:

## Allow unauthenticated access, uncomment to enable
##
# mysqlAllowEmptyPassword: true

## Create a database
##
# mysqlDatabase:

## Specify an imagePullPolicy (Required)
## It's recommended to change this to 'Always' if the image tag is 'latest'
## ref: http://kubernetes.io/docs/user-guide/images/#updating-images
##
imagePullPolicy: IfNotPresent

livenessProbe:
  initialDelaySeconds: 30
  periodSeconds: 10
  timeoutSeconds: 5
  successThreshold: 1
  failureThreshold: 3

readinessProbe:
  initialDelaySeconds: 5
  periodSeconds: 10
  timeoutSeconds: 1
  successThreshold: 1
  failureThreshold: 3

## Persist data to a persistent volume
persistence:
  enabled: true
  ## database data Persistent Volume Storage Class
  ## If defined, storageClassName: <storageClass>
  ## If set to "-", storageClassName: "", which disables dynamic provisioning
  ## If undefined (the default) or set to null, no storageClassName spec is
  ##   set, choosing the default provisioner.  (gp2 on AWS, standard on
  ##   GKE, AWS & OpenStack)
  ##
  # storageClass: "-"
  accessMode: ReadWriteOnce
  size: 8Gi

## Configure resource requests and limits
## ref: http://kubernetes.io/docs/user-guide/compute-resources/
##
resources:
  requests:
    memory: 256Mi
    cpu: 100m

# Custom mysql configuration files used to override default mysql settings
configurationFiles:
#  mysql.cnf: |-
#    [mysqld]
#    skip-name-resolve


## Configure the service
## ref: http://kubernetes.io/docs/user-guide/services/
service:
  ## Specify a service type
  ## ref: https://kubernetes.io/docs/concepts/services-networking/service/#publishing-services---service-types
  type: ClusterIP
  port: 3306
  # nodePort: 32000

我们可以直接在 YAML 格式的文件中来覆盖上面的任何配置，在安装的时候直接使用该配置文件即可：(config.yaml)

1
2
3
4
mysqlUser: syUser
mysqlDatabase: syDB
service:
  type: NodePort

指定该 yaml 文件

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
helm install -f config.yaml stable/mysql --name mydb
NAME:   mydb
LAST DEPLOYED: Wed Sep  5 00:09:44 2018
NAMESPACE: default
STATUS: DEPLOYED

RESOURCES:
==> v1/Secret
NAME        TYPE    DATA  AGE
mydb-mysql  Opaque  2     1s

==> v1/ConfigMap
NAME             DATA  AGE
mydb-mysql-test  1     1s

==> v1/PersistentVolumeClaim
NAME        STATUS   VOLUME  CAPACITY  ACCESS MODES  STORAGECLASS  AGE
mydb-mysql  Pending  1s

==> v1/Service
NAME        TYPE      CLUSTER-IP     EXTERNAL-IP  PORT(S)         AGE
mydb-mysql  NodePort  10.96.150.198  <none>       3306:32604/TCP  0s

==> v1beta1/Deployment
NAME        DESIRED  CURRENT  UP-TO-DATE  AVAILABLE  AGE
mydb-mysql  1        1        1           0          0s

==> v1/Pod(related)
NAME                        READY  STATUS   RESTARTS  AGE
mydb-mysql-dfc999888-hbw5d  0/1    Pending  0         0s
...

pod状况

1
2
3
kubectl get pods
NAME                                      READY     STATUS    RESTARTS   AGE
mydb-mysql-dfc999888-hbw5d                0/1       Pending   0          44m

看到是pending状态，describe查下：

1
2
3
4
Events:
  Type     Reason            Age                From               Message
  ----     ------            ----               ----               -------
  Warning  FailedScheduling  2m (x37 over 12m)  default-scheduler  pod has unbound PersistentVolumeClaims (repeated 2 times)

可以通过 storageclass 或者手动创建一个合适的 PV 对象来解决这个问题。

也可以更新helm，来直接禁用掉数据持久化，可以在上面的 config.yaml 文件中设置：

1
2
persistence:
  enabled: false

另外一种方法就是在安装过程中使用--set来覆盖对应的 value 值，比如禁用数据持久化，我们这里可以这样来覆盖：

1
helm install stable/mysql --set persistence.enabled=false --name mydb

升级

将数据持久化禁用掉来对上面的 mydb 进行升级：

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
[root@master101 sy]# echo config.yaml
mysqlUser: haimaxyUser
mysqlDatabase: haimaxyDB
service:
  type: NodePort
persistence:
  enabled: false


[root@master101 sy]# helm upgrade -f config.yaml mydb stable/mysql
helm upgrade -f config.yaml mydb stable/mysql
Release "mydb" has been upgraded. Happy Helming!
LAST DEPLOYED: Wed Sep  5 00:38:33 2018
NAMESPACE: default
STATUS: DEPLOYED

RESOURCES:
...

可以使用 helm history 命令查看 release 的历史版本：

1
2
3
4
helm history mydb
REVISION    UPDATED                     STATUS      CHART           DESCRIPTION
1           Wed June  17 00:09:44 2018    SUPERSEDED  mysql-0.10.1    Install complete
2           Wed June  17 00:38:33 2018    DEPLOYED    mysql-0.10.1    Upgrade complete
Donate