一、API资源对象Job
一次性运行后就退出的Pod
1.1 使用kubect生成YAML文件
# kubectl create job job01 --image=busybox --dry-run=client -o yaml >job01.yaml
# vim job01.yaml
# cat job01.yaml
apiVersion: batch/v1
kind: Job
metadata:
creationTimestamp: null
name: job01
spec:
template:
metadata:
creationTimestamp: null
spec:
containers:
- image: busybox
name: job01
comand: ["/bin/echo"]
args: ["Kubernetes","k8s!"]
restartPolicy: OnFailure1,.2 创建Job
# kubectl apply -f job01.yaml
job.batch/job01 created1.3 查看Job
# kubectl get job,pod
改容器运行完成后状态变成Completed。
对于Job，还有几个特殊字段：
- activeDeadlineSecond,设置Pod运行的超时时间。
- backoffLimit,设置Pod的失败重试次数。
- completions，Job完成需要运行多少个Pod，默认是1个。
- parallelism,它与completions相关，表示允许并发运行的Pod数量，避免过多占用资源。
vim myjob.yaml
apiVersion: batch/v1
kind: Job
metadata:
name: sleep-job
spec:
activeDeadlineSeconds: 60
backoffLimit: 2
completions: 4
parallelism: 2
template:
spec:
containers:
- image: busybox
name: echo-job
imagePullPolicy: IfNotPresent
command:
- sh
- -c
- sleep 10;echo done
restartPolicy: Never创建Job，并查看job情况
# kubectl apply -f myjob.yaml ;kubectl get pod -w
activeDeadlineSeconds: 15 15s就超时，completions要求运行的4个Pod没有执行完。修改为60s后再次运行
# kubectl apply -f myjob.yaml ;kubectl get pod -wkubectl apply -f myjob.yaml ;kubectl get pod -w
# kubectl apply -f myjob.yaml ;kubectl get pod -w
job.batch/sleep-job created
NAME READY STATUS RESTARTS AGE
ds-demo-57qcd 1/1 Running 1 (78m ago) 23h
ds-demo-jzlpn 1/1 Running 1 (77m ago) 23h
ds-demo-m8cmz 1/1 Running 1 (77m ago) 23h
ds-demo-sfqnt 1/1 Running 1 (79m ago) 23h
job01-8zngs 0/1 Completed 0 24m
ng-deploy-7b7ff4f9bc-d2g65 1/1 Running 1 (77m ago) 23h
ng-deploy-7b7ff4f9bc-s27c9 1/1 Running 1 (78m ago) 23h
nginxdp-7cf46d7445-8x6gs 1/1 Running 2 (77m ago) 2d11h
redis-sts-0 1/1 Running 0 64m
redis-sts-1 1/1 Running 0 72m
sleep-job-2gxtt 0/1 ContainerCreating 0 1s
sleep-job-bkltt 0/1 ContainerCreating 0 1s
testpod 1/1 Running 2 (78m ago) 2d
sleep-job-bkltt 0/1 ContainerCreating 0 1s
sleep-job-2gxtt 0/1 ContainerCreating 0 1s
sleep-job-2gxtt 1/1 Running 0 2s
sleep-job-bkltt 1/1 Running 0 2s
sleep-job-2gxtt 0/1 Completed 0 12s
sleep-job-bkltt 0/1 Completed 0 12s
sleep-job-2gxtt 0/1 Completed 0 13s
sleep-job-2gxtt 0/1 Completed 0 13s
sleep-job-bkltt 0/1 Completed 0 13s
sleep-job-bkltt 0/1 Completed 0 13s
sleep-job-2gxtt 0/1 Completed 0 14s
sleep-job-drplf 0/1 Pending 0 0s
sleep-job-drplf 0/1 Pending 0 0s
sleep-job-8mk7v 0/1 Pending 0 0s
sleep-job-8mk7v 0/1 Pending 0 0s
sleep-job-drplf 0/1 ContainerCreating 0 0s
sleep-job-8mk7v 0/1 ContainerCreating 0 0s
sleep-job-2gxtt 0/1 Completed 0 14s
sleep-job-bkltt 0/1 Completed 0 14s
sleep-job-bkltt 0/1 Completed 0 14s
sleep-job-drplf 0/1 ContainerCreating 0 0s
sleep-job-8mk7v 0/1 ContainerCreating 0 0s
sleep-job-drplf 1/1 Running 0 1s
sleep-job-8mk7v 1/1 Running 0 1s
sleep-job-drplf 0/1 Completed 0 11s
sleep-job-8mk7v 0/1 Completed 0 11s
sleep-job-drplf 0/1 Completed 0 12s
sleep-job-drplf 0/1 Completed 0 12s
sleep-job-8mk7v 0/1 Completed 0 12s
sleep-job-8mk7v 0/1 Completed 0 12s
sleep-job-drplf 0/1 Completed 0 13s
sleep-job-8mk7v 0/1 Completed 0 13s
sleep-job-drplf 0/1 Completed 0 13s
sleep-job-8mk7v 0/1 Completed 0 13s 
二、API资源对象CronJob
CronJob简称（cj）是一种周期运行的Pod，比如有些任务每天执行一次
使用kubectl生成YAML文件
# kubectl create cj cj01 --image=busybox --schedule="" --dry-run=client -o yaml >cj01.yamlvim cj01.yaml 编辑配置文件
apiVersion: batch/v1
kind: CronJob
metadata:
name: cj01
spec:
jobTemplate:
spec:
template:
spec:
containers:
- image: busybox
name: cj01
imagePullPolicy: IfNotPresent
command: ["/bin/echo"]
args: ["hello","kubernetes!"]
restartPolicy: OnFailure
schedule: "*/1 * * * *"运行并查看
# kubectl apply -f cj01.yaml
cronjob.batch/cj01 created
# kubectl get cj
NAME SCHEDULE SUSPEND ACTIVE LAST SCHEDULE AGE
cj01 */1 * * * * False 0 <none> 9s
三、API 资源对象Endpoint
Endpoint(简称ep)资源是和Service一一对应，每个Service都会对应一个Endpoint
# kubectl get ep
NAME ENDPOINTS AGE
kubernetes 192.168.1.230:6443 19d
nginxsvc 10.244.154.26:80 2d12h
ngx-svc 10.244.154.25:80,10.244.167.163:80 24h
redis-svc 10.244.154.28:6379,10.244.29.45:6379 22h
# kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 19d
nginxsvc NodePort 10.102.250.93 <none> 80:31681/TCP 2d12h
ngx-svc ClusterIP 10.97.206.107 <none> 8080/TCP 24h
redis-svc ClusterIP 10.110.151.202 <none> 6379/TCP 22hEndpoint 可以理解为Service后端对应的资源。
如果k8s里的Pod需要访问外部资源，比如访问外部MySQL服务，可以定义一个对外资源的Endpoint,然后再定义一个Service，这样k8s里面的其他Pod可以访问mysql服务。
vim testep.yaml
apiVersion: v1
kind: Endpoints
metadata:
name: external-mysql
subsets:
- addresses:
- ip: 192.168.1.230
ports:
- port: 3306
---
apiVersion: v1
kind: Service ##注意，该service里并不需要定义selector，只要Service name和Endpoint name保持一致即可
metadata:
name: external-mysql
spec:
ports:
- port: 3306应用YAML文件
# kubectl apply -f testep.yaml
endpoints/external-mysql created
service/external-mysql created测试
# kubectl get ep
NAME ENDPOINTS AGE
external-mysql 192.168.1.230:3306 22s
kubernetes 192.168.1.230:6443 19d
nginxsvc 10.244.154.26:80 2d12h
ngx-svc 10.244.154.25:80,10.244.167.163:80 24h
redis-svc 10.244.154.28:6379,10.244.29.45:6379 22h
# kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
external-mysql ClusterIP 10.109.90.174 <none> 3306/TCP 26s
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 19d
nginxsvc NodePort 10.102.250.93 <none> 80:31681/TCP 2d12h
ngx-svc ClusterIP 10.97.206.107 <none> 8080/TCP 24h
redis-svc ClusterIP 10.110.151.202 <none> 6379/TCP 22h进入testpod 安装mysql 客户端命令，访问mysql
验证见第四节。
四、API资源对象ConfigMap
ConfigMap(简称cm）用来存储配置信息，比如服务端口、运行参数、文件路径等。
4.1 YAML示例
apiVersion: v1
kind: ConfigMap
metadata:
name: mycm
data:
DATABASE: 'db'
USER: 'wp'
PASSWORD: '12345678'
ROOT_PASSWORD: '12345678'
HOST: 'external-mysql'创建cm
# kubectl apply -f mycm.yaml
configmap/mycm unchanged查看
# kubectl get cm
NAME DATA AGE
kube-root-ca.crt 1 19d
mycm 5 2d1h
# # kubectl describe cm mycm
Name: mycm
Namespace: default
Labels: <none>
Annotations: <none>
Data
====
DATABASE:
----
k8s
HOST:
----
external-mysql
PASSWORD:
----
12345678
ROOT_PASSWORD:
----
12345678
USER:
----
root
BinaryData
====
Events: <none>4.2 在其他Pod引用ConfigMap
vi testpod.yaml
# cat testpod.yaml
apiVersion: v1
kind: Pod
metadata:
name: testpod
labels:
app: testpod
spec:
containers:
- image: mariadb:10
name: maria1
imagePullPolicy: IfNotPresent
command: [ "/bin/bash", "-ce", "tail -f /dev/null" ]
ports:
- containerPort: 3306
envFrom: ##将cm里的字段全部导入该pod
- prefix: 'MARIADB_' ##将导入的字段名前面自动加上前缀，例如MARIADB_DATABASE， MARIADB_USER
configMapRef: ##定义哪个cm
name: mycm4.3 验证：
# kubectl exec -it testpod -- bash
# echo $MARIADB_PASSWORD
12345678
# echo $MARIADB_HOST
external-mysql
# echo $MARIADB_DATABASE
k8s
# mysql -u$MARIADB_USER -p$MARIADB_PASSWORD -h$MARIADB_HOST
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MariaDB connection id is 7
Server version: 5.5.68-MariaDB MariaDB Server
Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
MariaDB [(none)]> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| k8s |
| mysql |
| performance_schema |
| test |
+--------------------+
5 rows in set (0.001 sec)五、API资源对象Secret
Secret 和cm的结构和用法很类似，比如：
- 访问私有镜像仓库的认证信息
- 身份识别的凭证信息
- HTTPS通信的证书和私钥
- 一般的机密信息
5.1 YAML示例
vim mysecret.yaml
# cat mysecret.yaml
apiVersion: v1
kind: Secret
metadata:
name: mysecret
data:
host: ZXh0ZXJuYWwtbXlzcWw= #echo -n "external-mysql"|base64
user: cm9vdA== # echo -n "root"|base64
passwd: MTIzNDU2Nzg= ## echo -n "12345678"|base64查看
# kubectl apply -f mysecret.yaml
secret/mysecret created
# kubectl get secret
NAME TYPE DATA AGE
mysecret Opaque 3 33s
# kubectl describe secret mysecret
Name: mysecret
Namespace: default
Labels: <none>
Annotations: <none>
Type: Opaque
Data
====
user: 4 bytes
host: 14 bytes
passwd: 8 bytes5.2 在Pod引用Secret
vi testpod2.yaml
apiVersion: v1
kind: Pod
metadata:
name: testpod3
spec:
containers:
- image: mariadb:10
name: maria3
imagePullPolicy: IfNotPresent
command: ["/bin/sleep", "300"]
env:
- name: USERNAME
valueFrom:
secretKeyRef:
name: mysecret
key: user
- name: PASSWORD
valueFrom:
secretKeyRef:
name: mysecret
key: passwd
- name: HOST
valueFrom:
secretKeyRef:
name: mysecret
key: host5.3 验证：
# kubectl apply -f testpod3.yaml
pod/testpod3 unchanged
[root@master-1-230 2.16]# kubectl exec -it testpod3 -- bash
root@testpod3:/# echo $HOST
external-mysql
root@testpod3:/# echo $USERNAME
root
root@testpod3:/# echo $PASSWORD
12345678
root@testpod3:/# mysql -u$USERNAME -p$PASSWORD -h$HOST
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MariaDB connection id is 9
Server version: 5.5.68-MariaDB MariaDB Server
Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
MariaDB [(none)]> show databasses;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'databasses' at line 1
MariaDB [(none)]> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| k8s |
| mysql |
| performance_schema |
| test |
+--------------------+
5 rows in set (0.001 sec)