【k8s配置与存储--配置管理】

在这里插入图片描述

1、ConfigMap的配置

1.1 ConfigMap介绍

ConfigMap 是一种 API 对象，用来将非机密性的数据保存到键值对中。使用时， Pod 可以将其用作环境变量、命令行参数或者存储卷中的配置文件。
ConfigMap 将你的环境配置信息和容器镜像解耦，便于应用配置的修改。
注意：
ConfigMap 并不提供保密或者加密功能。如果你想存储的数据是机密的，请使用 Secret，或者使用其他第三方工具来保证你的数据的私密性，而不是用 ConfigMap。

1.2 ConfigMap 创建

使用 kubectl create configmap -h 查看演示例子

Examples:
  # Create a new config map named my-config based on folder bar
  kubectl create configmap my-config --from-file=path/to/bar

  # Create a new config map named my-config with specified keys instead of file basenames on disk
  kubectl create configmap my-config --from-file=key1=/path/to/bar/file1.txt --from-file=key2=/path/to/bar/file2.txt

  # Create a new config map named my-config with key1=config1 and key2=config2
  kubectl create configmap my-config --from-literal=key1=config1 --from-literal=key2=config2

  # Create a new config map named my-config from the key=value pairs in the file
  kubectl create configmap my-config --from-file=path/to/bar

  # Create a new config map named my-config from an env file
  kubectl create configmap my-config --from-env-file=path/to/foo.env --from-env-file=path/to/bar.env

1.2.1 查看下k8s已经创建好的configmap

可以看到这个信息是存储的一个key信息

[root@k8s-master configmap]# kubectl get configmaps
NAME               DATA   AGE
kube-root-ca.crt   1      6d1h

[root@k8s-master configmap]# kubectl describe configmaps kube-root-ca.crt
Name:         kube-root-ca.crt
Namespace:    default
Labels:       <none>
Annotations:  kubernetes.io/description:
                Contains a CA bundle that can be used to verify the kube-apiserver when using internal endpoints such as the internal service IP or kubern...

Data
====
ca.crt:
----
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----


BinaryData
====

Events:  <none>

1.2.2 指定目录进行创建：kubectl create configmap my-config --from-file=path/to/bar

[root@k8s-master configmap]# cat db.properties
user: root
passwd: 123456
host: 127.0.0.1

[root@k8s-master configmap]# cat host.properties
k8s-master: 10.10.10.100
k8s-node-01: 10.10.10.177
k8s-node-02: 10.10.10.113

[root@k8s-master configmap]# kubectl create configmap my-config-test1 --from-file=/root/configmap/
configmap/my-config-test1 created

[root@k8s-master configmap]# kubectl describe configmaps my-config-test1
Name:         my-config-test1
Namespace:    default
Labels:       <none>
Annotations:  <none>

Data
====
db.properties:
----
user: root
passwd: 123456
host: 127.0.0.1

host.properties:
----
k8s-master: 10.10.10.100
k8s-node-01: 10.10.10.177
k8s-node-02: 10.10.10.113


BinaryData
====

Events:  <none>

1.2.3 指定文件进行创建：kubectl create configmap my-config --from-file=key1=/path/to/bar/file1.txt

–from-file=key1=/path/to/bar/file1.txt
这里的key1相当于是给指定的这个文件进行改名

[root@k8s-master configmap]# kubectl create configmap my-config-test2  --from-file=mykey=db.properties
configmap/my-config-test2 created
[root@k8s-master configmap]# kubectl describe configmaps my-config-test2
Name:         my-config-test2
Namespace:    default
Labels:       <none>
Annotations:  <none>

Data
====
mykey:
----
user: root
passwd: 123456
host: 127.0.0.1


BinaryData
====

Events:  <none>

1.2.4 通过命令行创建：kubectl create configmap my-config --from-literal=key1=config1 --from-literal=key2=config2

[root@k8s-master configmap]# kubectl create  configmap my-config-test3  --from-literal=name=school  --from-literal=id=bj
configmap/my-config-test3 created
[root@k8s-master configmap]# kubectl describe configmaps my-config-test3
Name:         my-config-test3
Namespace:    default
Labels:       <none>
Annotations:  <none>

Data
====
id:
----
bj
name:
----
school

BinaryData
====

Events:  <none>
[root@k8s-master configmap]#

1.3 ConfigMap的使用

创建一个configmap的资源，在创建一个pod，把这个configmap的资源加载到pod里。

1.3.1 创建configmap

root@k8s-master configmap]# kubectl create configmap env-test  --from-literal=JAVA_HOME='/usr/local/jdk1.8/'  --from-literal=Name='您好~'
configmap/env-test created
[root@k8s-master configmap]# kubectl describe configmaps env-test
Name:         env-test
Namespace:    default
Labels:       <none>
Annotations:  <none>

Data
====
JAVA_HOME:
----
/usr/local/jdk1.8/
Name:
----
您好~

BinaryData
====

Events:  <none>

1.3.2 创建pod资源

apiVersion: v1
kind: Pod
metadata:
  name: test-env-cm
spec:
  containers:
    - name: env-test
      image: alpine
      imagePullPolicy: IfNotPresent
      command: ["/bin/sh","-c","env  ; sleep 3600"]
      env:
      - name: JAVA_HOME_VM
        valueFrom:
          configMapKeyRef:
            name: env-test  # configmap的名字
            key: JAVA_HOME  # 表示从name的configmap种获取名字为key的value，将其赋值给本地环境变量 JAVA_HOME_VM
      - name: Name_VM
        valueFrom:
          configMapKeyRef:
            name: env-test
            key: Name
  restartPolicy: Never

[root@k8s-master configmap]# kubectl create -f env-test.yaml
pod/test-env-cm created

[root@k8s-master configmap]# kubectl get po
NAME                           READY   STATUS    RESTARTS      AGE
dns-test                       1/1     Running   1 (45h ago)   45h
fluentd-59k8k                  1/1     Running   0             27h
fluentd-hhtls                  1/1     Running   0             27h
nginx-deploy-fdd948cf4-69b85   1/1     Running   0             23h
nginx-deploy-fdd948cf4-r8ktj   1/1     Running   0             27h
test-env-cm                    1/1     Running   0             21s

1.3.3 通过日志查看刚才的configmap信息是否在env中

在这里插入图片描述

1.3.4 通过volumes 加载configmap

apiVersion: v1
kind: Pod
metadata:
  name: test-configfile-po
spec:
  containers:
    - name: env-test
      image: alpine
      imagePullPolicy: IfNotPresent
      command: ["/bin/sh","-c","env  ; sleep 3600"]
      env:
      - name: JAVA_HOME_VM
        valueFrom:
          configMapKeyRef:
            name: env-test  # configmap的名字
            key: JAVA_HOME  # 表示从name的configmap种获取名字为key的value，将其赋值给本地环境变量 JAVA_HOME_VM
      - name: Name_VM
        valueFrom:
          configMapKeyRef:
            name: env-test
            key: Name
      volumeMounts:  #  加载数据卷
      - name: db-config  # 加载数据卷的名字
        mountPath: "/opt/test/"   #将数据卷加载到什么目录
        readOnly: true  #  是否只读
  volumes: # 数据卷挂载configmap、secret
    - name: db-config #数据卷的名字，随意设置
      configMap: # 数据卷类型为ConfigMap
        name: my-config-test1  #configMap的名字，必须跟想要加载的configmap相同
        items: #对configmap中的key进行映射，如果不指定，默认会讲configmap中所有  key全部转换为一个个同名的文件
          - key: "db.properties" # configMap中的key
            path: "db,properties"#将该key的值转换为文件
  restartPolicy: Never

通过以下容器内的文件信息可以看到，上文创建的yaml文件中对my-config-test1这个configmap种的iterm进行了定义，但是我们的这个configmap配置文件中包含了两个文件，iterms中只加载了db，并没有加载hosts。容器中的文件只有db，没有hosts。
如果不定义iterms，name就会加载全部信息。

在这里插入图片描述


[root@k8s-master configmap]# kubectl create -f test-file-po.yaml
pod/test-configfile-po created

[root@k8s-master configmap]# kubectl get po
NAME                           READY   STATUS    RESTARTS      AGE
dns-test                       1/1     Running   1 (45h ago)   45h
fluentd-59k8k                  1/1     Running   0             28h
fluentd-hhtls                  1/1     Running   0             28h
nginx-deploy-fdd948cf4-69b85   1/1     Running   0             23h
nginx-deploy-fdd948cf4-r8ktj   1/1     Running   0             27h
test-configfile-po             1/1     Running   0             7s
[root@k8s-master configmap]# kubectl exec -it test-configfile-po  -- sh
/ # cd /opt/test/
/opt/test # ll
sh: ll: not found
/opt/test # ls
db,properties
/opt/test # cat db,properties
user: root
passwd: 123456
host: 127.0.0.1
/opt/test # echo $JAVA_HOME_VM
/usr/local/jdk1.8/
/opt/test # echo $Name_Vm

/opt/test # echo $Name_VM
您好~

2、加密数据配置Secret

2.1 Secret 介绍

与ConfigMap类似，用于存储配置信息，但是主要用于存储敏感信息、需要加密的信息，Secret可以提供数据加密、解密功能。
在创建Secret时，要注意如果要加密的字符中，包含了有特殊字符，需耍使用转义符转移。eg： $ 转移后为"转移符号\加上$"，
也可以对特殊字符使用单引号描述，这样就不需要转义。
eg：1$289*-！转换为 "1$289*-! "
场景使用：多用于docker镜像私有仓库的使用。
加密方式为base64，可以通过 “echo “xxxx”| base64 --decode” 解密

2.2 Secret的创建

可以通过查询kubectl create secret -h命令查询secret的创建

[root@k8s-master ~]#   kubectl create secret -h
Create a secret using specified subcommand.

Available Commands:
  docker-registry   创建一个给 Docker registry 使用的 Secret
  generic           Create a secret from a local file, directory, or literal value
  tls               创建一个 TLS secret

Usage:
  kubectl create secret [flags] [options]

Use "kubectl <command> --help" for more information about a given command.
Use "kubectl options" for a list of global command-line options (applies to all commands).

2.2.1 创建secret资源

通过下面的命令就可以创建secret了。

[root@k8s-master ~]#   kubectl create secret -h
Create a secret using specified subcommand.

Available Commands:
  docker-registry   创建一个给 Docker registry 使用的 Secret
  generic           Create a secret from a local file, directory, or literal value
  tls               创建一个 TLS secret

Usage:
  kubectl create secret [flags] [options]

Use "kubectl <command> --help" for more information about a given command.
Use "kubectl options" for a list of global command-line options (applies to all commands).
  
[root@k8s-master ~]# kubectl create secret generic  test-secrete   --from-literal=username=admin --from-literal=password='12123421'
secret/test-secrete created

2.2.2 通过describe查看secret的描述

[root@k8s-master ~]# kubectl describe secrets test-secrete
Name:         test-secrete
Namespace:    default
Labels:       <none>
Annotations:  <none>

Type:  Opaque

Data
====
password:  8 bytes
username:  5 bytes

2.2.3 通过edit 查看secret的信息

k8s-master    Ready    control-plane   6d14h   v1.25.0
# Please edit the object below. Lines beginning with a '#' will be ignored,
# and an empty file will abort the edit. If an error occurs while saving this file will be
# reopened with the relevant failures.
#
apiVersion: v1
data:
  password: MTIxMjM0MjE=
  username: YWRtaW4=
kind: Secret
metadata:
  creationTimestamp: "2024-02-26T04:28:18Z"
  name: test-secrete
  namespace: default
  resourceVersion: "519877"
  uid: 8c981ce2-7cb2-4030-8fdd-b496ae72a4fa
type: Opaque

2.2.4 通过base64反编译这个信息

通过base64 反编译出原信息，可以看到这种加密方式不是很安全

[root@k8s-master ~]# echo "MTIxMjM0MjE="  | base64 --decode
12123421

[root@k8s-master ~]# echo "YWRtaW4="  | base64 --decode
admin

2.3 secret的使用

2.3.1 创建一个docke-registry的secret

[root@k8s-master ~]#   kubectl create secret docker-registry   docker-test-secret --docker-username='lianhetiyu@1949945210135676'   --docker-password='Lanhe@123456'  --docker-email='admin@test.com'  --docker-server='registry.cn-hangzhou.aliyuncs.com'
secret/docker-test-secret created
[root@k8s-master ~]# kubectl describe sercet docker-test-secret
error: the server doesn't have a resource type "sercet"
[root@k8s-master ~]# kubectl describe secret docker-test-secret
Name:         docker-test-secret
Namespace:    default
Labels:       <none>
Annotations:  <none>

Type:  kubernetes.io/dockerconfigjson

Data
====
.dockerconfigjson:  215 bytes


[root@k8s-master ~]# kubectl edit secrets test-secrete
Edit cancelled, no changes made.
[root@k8s-master ~]#
# Please edit the object below. Lines beginning with a '#' will be ignored,
# and an empty file will abort the edit. If an error occurs while saving this file will be
# reopened with the relevant failures.
#
apiVersion: v1
data:
  .dockerconfigjson: ey89JhdXRocyI6eyJyZWdpc3RyeS5jbi1oYW5nemhvdS5hbGl5dW5jcy5jb20iOnsidXNlcm5hbWUiOiJsaWFuaGV0aXl1X3doZEAxOTQ5OTQ1MjEwMTM1Njc2IiwicGFzc3dvcmQiOiJMYW5oZUAxMjM0NTYiLCJlbWFpbCI6ImFkbWluQHRlc3QuY29tIiwiYXV0aCI6ImJHbGhibWhsZEdsNWRWOTNhR1JBTVRrME9UazBOVEl4TURFek5UWTNOanBNWVc1b1pVQXhNak0wTlRZPSJ9fX0=
kind: Secret
metadata:
  creationTimestamp: "2024-02-26T06:28:49Z"
  name: docker-test-secret
  namespace: default
  resourceVersion: "530968"
  uid: d31bb3f3-6111-4848-ab51-a894df2f1be1
type: kubernetes.io/dockerconfigjson

2.3.2 创建一个拉取镜像的新pod

apiVersion: v1
kind: Pod
metadata:
  name: test-configfile-po
spec:
  imagePullSecrets:  # 配置docke仓库：docker registry 的 secret
  - name: docker-test-secret
  containers:
    - name: env-test
      image: alpine
      imagePullPolicy: IfNotPresent
      command: ["/bin/sh","-c","env  ; sleep 3600"]
      env:
      - name: JAVA_HOME_VM
        valueFrom:
          configMapKeyRef:
            name: env-test  # configmap的名字
            key: JAVA_HOME  # 表示从name的configmap种获取名字为key的value，将其赋值给本地环境变量 JAVA_HOME_VM
      - name: Name_VM
        valueFrom:
          configMapKeyRef:
            name: env-test
            key: Name
  restartPolicy: Never

2.3.3 可以通过容器的描述引用了secret资源下载镜像


[root@k8s-master configmap]# kubectl create  -f   test-docker-po.yaml
pod/test-configfile-po created


[root@k8s-master configmap]# kubectl get  po  test-configfile-po
NAME                 READY   STATUS    RESTARTS   AGE
test-configfile-po   1/1     Running   0          2m57s


[root@k8s-master configmap]# kubectl describe po  test-configfile-po
Name:             test-configfile-po
Namespace:        default
Priority:         0
Service Account:  default
Node:             k8s-node-02/10.10.10.113
Start Time:       Mon, 26 Feb 2024 16:28:01 +0800
Labels:           <none>
Annotations:      <none>
Status:           Running
IP:               10.2.1.64
IPs:
  IP:  10.2.1.64
Containers:
  env-test:
    Container ID:  docker://cbcb9ece8da46b593a766c8d0d0247e3a02a0316ba24164e3ce3d5d8bf823829
    Image:         registry.cn-hangzhou.aliyuncs.com/lhty/controller:2.1
    Image ID:      docker-pullable://registry.cn-hangzhou.aliyuncs.com/lhty/controller@sha256:96f3490f6b7693caad23f2ce143d0e23516527edcd3448589cb9498011ba19c3
    Port:          <none>
    Host Port:     <none>
    Command:
      /bin/sh
      -c
      env  ; sleep 3600
    State:          Running
      Started:      Mon, 26 Feb 2024 16:29:12 +0800
    Ready:          True
    Restart Count:  0
    Environment:
      JAVA_HOME_VM:  <set to the key 'JAVA_HOME' of config map 'env-test'>  Optional: false
      Name_VM:       <set to the key 'Name' of config map 'env-test'>       Optional: false
    Mounts:
      /opt/test/ from db-config (ro)
      /var/run/secrets/kubernetes.io/serviceaccount from kube-api-access-nwsh6 (ro)
Conditions:
  Type              Status
  Initialized       True
  Ready             True
  ContainersReady   True
  PodScheduled      True
Volumes:
  db-config:
    Type:      ConfigMap (a volume populated by a ConfigMap)
    Name:      my-config-test1
    Optional:  false
  kube-api-access-nwsh6:
    Type:                    Projected (a volume that contains injected data from multiple sources)
    TokenExpirationSeconds:  3607
    ConfigMapName:           kube-root-ca.crt
    ConfigMapOptional:       <nil>
    DownwardAPI:             true
QoS Class:                   BestEffort
Node-Selectors:              <none>
Tolerations:                 node.kubernetes.io/not-ready:NoExecute op=Exists for 300s
                             node.kubernetes.io/unreachable:NoExecute op=Exists for 300s
Events:
  Type    Reason     Age   From               Message
  ----    ------     ----  ----               -------
  Normal  Scheduled  75s   default-scheduler  Successfully assigned default/test-configfile-po to k8s-node-02
  Normal  Pulling    75s   kubelet            Pulling image "registry.cn-hangzhou.aliyuncs.com/lhty/controller:2.1"
  Normal  Pulled     6s    kubelet            Successfully pulled image "registry.cn-hangzhou.aliyuncs.com/lhty/controller:2.1" in 1m8.912792712s
  Normal  Created    5s    kubelet            Created container env-test
  Normal  Started    5s    kubelet            Started container env-test

通过docker images，可以看到有刚才通过阿里云仓库拉取的镜像

在这里插入图片描述

3、SubPath的使用

场景需求：把nginx中的conf文件制作为一个configmap，后续想改动nginx的配置文件，我们只需要更新这个configmap即可，不需要重新登录进nginx容器内修改conf文件。但是

3.1 为什么需要使用SubPath？

使用configmap加载的文件到容器内目录后，如果原先有这个目录，会直接覆盖原先的目录，原先目录中的内容会丢失。

3.1.1 创建一个nginx配置文件的configmap

# 拿到容器中的nginx配置文件
root@k8s-master configmap]# kubectl exec nginx-deploy-fdd948cf4-69b85 -it -- sh -c "cat /etc/nginx/nginx.conf"  > nginx-conf-cm.conf


## 创建这个configmap
[root@k8s-master configmap]# kubectl create cm nginx-conf-cm  --from-file nginx-conf-cm.conf
configmap/nginx-conf-cm created
[root@k8s-master configmap]# kubectl describe cm nginx-conf-cm
Name:         nginx-conf-cm
Namespace:    default
Labels:       <none>
Annotations:  <none>

Data
====
nginx-conf-cm.conf:
----

user  nginx;
worker_processes  auto;

error_log  /var/log/nginx/error.log notice;
pid        /var/run/nginx.pid;


events {
    worker_connections  1024;
}


http {
    include       /etc/nginx/mime.types;
    default_type  application/octet-stream;

    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';

    access_log  /var/log/nginx/access.log  main;

    sendfile        on;
    #tcp_nopush     on;

    keepalive_timeout  65;

    #gzip  on;

    include /etc/nginx/conf.d/*.conf;
}


BinaryData
====

Events:  <none>

3.1.2 修改deploy信息

nginx的pod是通过deployment创建的，所以只需要修改deployment信息就可以更新nginx了。

[root@k8s-master configmap]# kubectl get deployments.apps
NAME           READY   UP-TO-DATE   AVAILABLE   AGE
nginx-deploy   2/2     2            2           43h
[root@k8s-master configmap]# kubectl get po
NAME                           READY   STATUS    RESTARTS        AGE
dns-test                       1/1     Running   2 (5h14m ago)   2d14h
fluentd-59k8k                  1/1     Running   1 (5h14m ago)   44h
fluentd-hhtls                  1/1     Running   1 (5h14m ago)   44h
nginx-deploy-fdd948cf4-69b85   1/1     Running   1 (5h14m ago)   40h
nginx-deploy-fdd948cf4-r8ktj   1/1     Running   1 (5h14m ago)   43h
test-configfile-po             1/1     Running   0               18m


## 通过edit deploy nginx-deploy文件添加如下内容，如下内容需要和 containers 同一级别。
containers
  command: ['/bin/sh','-c','nginx daemon off; sleep 3600']  # 为了防止容器启动失败。
  volumesMounts:
  - name: nginx-conf
    mountPath: '/etc/nginx'
volumes:
- name: nginx-conf
  configMap:
  - name: nginx-conf-cm   # configmap的名字
    items:
    - key: nginx-conf-cm.conf  # configmap种文件的名字
      path: nginx.conf

在这里插入图片描述

3.1.3 查看更新后过的nginx pod

[root@k8s-master configmap]# kubectl get po
NAME                            READY   STATUS      RESTARTS        AGE
dns-test                        1/1     Running     2 (5h57m ago)   2d14h
fluentd-59k8k                   1/1     Running     1 (5h58m ago)   45h
fluentd-hhtls                   1/1     Running     1 (5h57m ago)   45h
nginx-deploy-7d6db4657b-7pzc2   1/1     Running     0               38s
nginx-deploy-7d6db4657b-qq8sc   1/1     Running     0               40s
test-configfile-po              0/1     Completed   0               62m
[root@k8s-master configmap]# kubectl describe po nginx-deploy-7d6db4657b-7pzc2
Name:             nginx-deploy-7d6db4657b-7pzc2
Namespace:        default
Priority:         0
Service Account:  default
Node:             k8s-node-01/10.10.10.177
Start Time:       Mon, 26 Feb 2024 17:29:41 +0800
Labels:           app=nginx-deploy
                  pod-template-hash=7d6db4657b
Annotations:      <none>
Status:           Running
IP:               10.2.2.39
IPs:
  IP:           10.2.2.39
Controlled By:  ReplicaSet/nginx-deploy-7d6db4657b
Containers:
  nginx:
    Container ID:  docker://6b349ede9bb23d51add64c24b28bab4a5df2804ea7bbe0e5efdcc97ba405a005
    Image:         nginx:1.20
    Image ID:      docker-pullable://nginx@sha256:03f3cb0afb7bd5c76e01bfec0ce08803c495348dccce37bcb82c347b4853c00b
    Port:          <none>
    Host Port:     <none>
    Command:
      /bin/sh
      -c
      nginx daemon off; sleep 3600
    State:          Running
      Started:      Mon, 26 Feb 2024 17:29:42 +0800
    Ready:          True
    Restart Count:  0
    Limits:
      cpu:     200m
      memory:  128Mi
    Requests:
      cpu:        100m
      memory:     128Mi
    Environment:  <none>
    Mounts:
      /etc/nginx/ from nginx-conf (rw)
      /var/run/secrets/kubernetes.io/serviceaccount from kube-api-access-9xskq (ro)
Conditions:
  Type              Status
  Initialized       True
  Ready             True
  ContainersReady   True
  PodScheduled      True
Volumes:
  nginx-conf:
    Type:      ConfigMap (a volume populated by a ConfigMap)
    Name:      nginx-conf-cm
    Optional:  false
  kube-api-access-9xskq:
    Type:                    Projected (a volume that contains injected data from multiple sources)
    TokenExpirationSeconds:  3607
    ConfigMapName:           kube-root-ca.crt
    ConfigMapOptional:       <nil>
    DownwardAPI:             true
QoS Class:                   Burstable
Node-Selectors:              <none>
Tolerations:                 node.kubernetes.io/not-ready:NoExecute op=Exists for 300s
                             node.kubernetes.io/unreachable:NoExecute op=Exists for 300s
Events:
  Type    Reason     Age   From               Message
  ----    ------     ----  ----               -------
  Normal  Scheduled  85s   default-scheduler  Successfully assigned default/nginx-deploy-7d6db4657b-7pzc2 to k8s-node-01
  Normal  Pulled     85s   kubelet            Container image "nginx:1.20" already present on machine
  Normal  Created    85s   kubelet            Created container nginx
  Normal  Started    85s   kubelet            Started container nginx

3.1.4 /etc/nginx/ 这个路径下只有一个nginx的配置文件，其他文件全部没了

[root@k8s-master configmap]# kubectl exec -it  nginx-deploy-7d6db4657b-7pzc2  -- sh  -c  'ls /etc/nginx/'
nginx.conf
[root@k8s-master configmap]# kubectl exec -it  nginx-deploy-7d6db4657b-7pzc2  -- sh  -c  'cat  /etc/nginx/nginx.conf'

user  nginx;
worker_processes  auto;

error_log  /var/log/nginx/error.log notice;
pid        /var/run/nginx.pid;


events {
    worker_connections  1024;
}


http {
    include       /etc/nginx/mime.types;
    default_type  application/octet-stream;

    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';

    access_log  /var/log/nginx/access.log  main;

    sendfile        on;
    #tcp_nopush     on;

    keepalive_timeout  65;

    #gzip  on;

    include /etc/nginx/conf.d/*.conf;
}

3.2 如何使用SubPath？

1、定义volumes时需要增加items属性，配置key和path，且path的值不能从/开始
2、在容器内的volumeMounts中增加subPath黑性，该值与volumes中tems.path的值相同。

3.2.1 修改deploy，添加subPath

在这里插入图片描述

3.2.2 在进容器查看下/etc/nginx目录内容

在这里插入图片描述

4、配置的热更新

我们通常会将项目的配置文件作为configmap然后挂载到pod,那么如果更新configmap中的配置，会不会更新到pod中呢？
这得分成几种情况：
默认方式：会更新，更新同期是更新间+缓存时间
subPath:不会更新
变量形式：如果pod中的一个变量是从configmap或secret中得到，同样也是不会更新的。
对于subPath的方式，我们可以取消subPath的使用，将配置文件挂载到一个不存在的目录，避免目录的夏盖，然后再利用软连接的形式，将该文件链接到目标位置。

4.1 通过edit 命令直接修改configmap

4.1.1 创建一个pod

apiVersion: v1
kind: Pod
metadata:
  name: configfile-po
spec:
  containers:
    - name: configmap-po
      image: alpine
      imagePullPolicy: IfNotPresent
      command: ["/bin/sh","-c","env  ; sleep 3600"]
      volumeMounts:  #  加载数据卷
      - name: db-config  # 加载数据卷的名字
        mountPath: "/opt/test/"   #将数据卷加载到什么目录
        readOnly: true  #  是否只读
  volumes: # 数据卷挂载configmap、secret
    - name: db-config #数据卷的名字，随意设置
      configMap: # 数据卷类型为ConfigMap
        name: my-config-test1  #configMap的名字，必须跟想要加载的configmap相同
        items: #对configmap中的key进行映射，如果不指定，默认会讲configmap中所有  key全部转换为一个个同名的文件
          - key: "db.properties" # configMap中的key
            path: "db.txt" # 将该key的值转换为文件
  restartPolicy: Never

[root@k8s-master configmap]# kubectl get cm
NAME               DATA   AGE
env-test           2      18h
kube-root-ca.crt   1      6d20h
my-config-test1    2      18h
my-config-test3    2      18h
nginx-conf-cm      1      102m


[root@k8s-master configmap]# kubectl create -f configfile-po.yaml
pod/configfile-po created

[root@k8s-master configmap]# kubectl get po
NAME                           READY   STATUS    RESTARTS        AGE
configfile-po                  1/1     Running   0               20s
dns-test                       1/1     Running   2 (6h53m ago)   2d15h
fluentd-59k8k                  1/1     Running   1 (6h53m ago)   46h
fluentd-hhtls                  1/1     Running   1 (6h53m ago)   46h
nginx-deploy-6fb8d6548-8khhv   1/1     Running   0               31m
nginx-deploy-6fb8d6548-fd9tx   1/1     Running   0               31m
[root@k8s-master configmap]# kubectl  exec -it configfile-po  -- sh -c 'cat /opt/test/db.txt '
user: root
passwd: 123456
host: 127.0.0.1

4.1.2 通过edit编辑my-config-test1，给configmap中添加一条信息

在这里插入图片描述

4.1.3 查看容器中的内容更新情况（需要等一段时间才会更新）

[root@k8s-master configmap]# kubectl  exec -it configfile-po  -- sh -c 'cat /opt/test/db.txt '
user: root
passwd: 123456
host: 127.0.0.1
date: '2024-02-26'

4.2 通过replace进行更新

由于conigmap我们创建通常都是基于文件创建，并不会编写yaml配置文件，因比修改时我们也是直接修改配置文件，而replace是没有 --from-file 参数的，因此无法实现基于源配置文件的替换，此时我们可以利用下方的命令实现

该命令的重点在于 --dry-run 参数，该参数的意思打印yaml文件，但不会将该文件发送给api-server,再结合 -o yaml输出yaml文件就可以得到一个配置好但是没有发给api-server的文件，然后再结合replace监听控制台得到yaml数据即可实现替换。
kubectl create cm --from-file=nginx.conf --dry-run -o yaml | kubectl replace-f-

4.2.1 更新需要添加到configmap的文件

[root@k8s-master configmap]#  echo 'service: test'  >>  ./file/db.properties

4.2.2 通过 kubectl create cm --from-file=nginx.conf --dry-run -o yaml | kubectl replace-f- 更新configmap

[root@k8s-master configmap]# kubectl create cm   my-config-test1  --from-file=./file/   --dry-run -o yaml
W0226 21:19:22.889508   89629 helpers.go:639] --dry-run is deprecated and can be replaced with --dry-run=client.
apiVersion: v1
data:
  db.properties: |
    user: root
    passwd: 123456
    host: 127.0.0.1
    service: test
  host.properties: |
    k8s-master: 10.10.10.100
    k8s-node-01: 10.10.10.177
    k8s-node-02: 10.10.10.113
kind: ConfigMap
metadata:
  creationTimestamp: null
  name: my-config-test1


[root@k8s-master configmap]# kubectl create cm   my-config-test1  --from-file=./file/   --dry-run -o yaml | kubectl replace -f-
W0226 21:21:09.680288   90368 helpers.go:639] --dry-run is deprecated and can be replaced with --dry-run=client.
configmap/my-config-test1 replaced
[root@k8s-master configmap]#

4.2.3 查看configmap

[root@k8s-master configmap]# kubectl describe  cm my-config-test1
Name:         my-config-test1
Namespace:    default
Labels:       <none>
Annotations:  <none>

Data
====
db.properties:
----
user: root
passwd: 123456
host: 127.0.0.1
service: test

host.properties:
----
k8s-master: 10.10.10.100
k8s-node-01: 10.10.10.177
k8s-node-02: 10.10.10.113


BinaryData
====

Events:  <none>

4.2.4 查看容器内文件，已经更新

[root@k8s-master configmap]# kubectl exec -it  configfile-po   -- sh -c 'cat /opt/test/db.txt'
user: root
passwd: 123456
host: 127.0.0.1
service: test

5、不可变的configmap和secret

对于一些敏感服务的配置文件，在线上有时是不允许修改的，此时在配置configmap时可以设置 immutable:true 来禁止修改

5.1 查看之前创建的my-confgi-test1这个configmap配置

[root@k8s-master configmap]# kubectl describe cm my-config-test1
Name:         my-config-test1
Namespace:    default
Labels:       <none>
Annotations:  <none>

Data
====
db.properties:
----
user: root
passwd: 123456
host: 127.0.0.1
service: test

host.properties:
----
k8s-master: 10.10.10.100
k8s-node-01: 10.10.10.177
k8s-node-02: 10.10.10.113


BinaryData
====

Events:  <none>