系統整理K8S的配置管理實戰-建議收藏系列
- 2022 年 11 月 7 日
- 筆記
- Kubernetes
原文公眾號鏈接://mp.weixin.qq.com/s/gZx-IIW1g9-Kl7yXw7tsEA
原文公眾號鏈接://mp.weixin.qq.com/s/gZx-IIW1g9-Kl7yXw7tsEA
一、ConfigMap
應用部署的最佳實踐都趨向於將應用所需要的配置資訊和應用程式本身離開,以便實現通過不同的配置實現更靈活的功能。
我們都知道,K8S中運行的是容器,若不將配置文件抽離,每一次配置文件的變動,都需要重新製作鏡像,這其實挺麻煩挺沒必要的。
在K8S中提供了ConfigMap資源對象作為配置管理的統一管理方案,可以通過環境變數或者文件的方式,在創建容器的時候將配置資訊動態注入到容器中~
下文開始對ConfigMap的實戰
官網文檔://kubernetes.io/zh/docs/concepts/configuration/configmap/
1.1、創建
1.1.1、from-file
準備目錄和文件
# 創建目錄及配置文件
[root@master01 yamls]# ls conf/
nginx.conf redis.conf
[root@master01 yamls]# cat conf/nginx.conf
app.name=nginx
location.prefix=/app
[root@master01 yamls]# cat conf/redis.conf
ip=10.10.10.101
port=2379
創建cm
[root@master01 yamls]# kubectl create cm -h
# --from-file參數既可以指定文件又可以指定目錄
[root@master01 yamls]# kubectl create cm cm-from-file --from-file=conf/
configmap/cm-from-file created
查看
[root@master01 yamls]# kubectl get cm
NAME DATA AGE
cm-from-file 2 38s
kube-root-ca.crt 1 17d
[root@master01 yamls]# kubectl get cm cm-from-file -oyaml
apiVersion: v1
data:
# 默認的data的key值就是文件名
# 可以在創建時通過參數 --from-file=abc=nginx.conf的方式將data.key改成abc
nginx.conf: |
app.name=nginx
location.prefix=/app
redis.conf: |
ip=10.10.10.101
port=2379
kind: ConfigMap
metadata:
creationTimestamp: "2022-03-31T00:52:21Z"
name: cm-from-file
namespace: default
resourceVersion: "759788"
uid: 5a41bdbe-66d0-45fa-8a5e-b6f6b005d671
1.1.2、from-env-file
env環境變數的格式為:key=value
指定參數:--from-env-file
而不是--from-file
[root@master01 yamls]# kubectl create cm cm-env-file --from-env-file=conf/nginx.conf
configmap/cm-env-file created
[root@master01 yamls]# kubectl get cm cm-env-file -oyaml
apiVersion: v1
data:
app.name: nginx
location.prefix: /app
kind: ConfigMap
metadata:
creationTimestamp: "2022-03-31T01:04:12Z"
name: cm-env-file
namespace: default
resourceVersion: "761496"
uid: 8e885d31-0a83-423c-a59f-6ea8b0473103
1.1.3、from-literal
literal(翻譯為:字面意義的)直接在命令行上指定好key和value
參數:--from-literal
[root@master01 ~]# kubectl create cm env-from-literal --from-literal=Level=INFO --from-literal=Name=Mac
configmap/env-from-literal created
[root@master01 ~]# kubectl get cm env-from-literal -oyaml
apiVersion: v1
data:
Level: INFO
Name: Mac
kind: ConfigMap
metadata:
creationTimestamp: "2022-04-01T00:31:13Z"
name: env-from-literal
namespace: default
resourceVersion: "762641"
uid: da2f8922-8385-46ba-82e9-b0dc197a1eb2
[root@master01 ~]#
1.1.4、基於yaml文件創建
apiVersion: v1
kind: ConfigMap
metadata:
name: game-demo
data:
# 類屬性鍵;每一個鍵都映射到一個簡單的值
player_initial_lives: "3"
ui_properties_file_name: "user-interface.properties"
# 類文件鍵
game.properties: |
enemy.types=aliens,monsters
player.maximum-lives=5
user-interface.properties: |
color.good=purple
color.bad=yellow
allow.textmode=true
1.2、Pod使用ConfigMap
1.2.1、valueFrom
推薦將下面這種kv格式的configMap注入為容器的配置文件
[root@master01 yamls]# kubectl get cm cm-env-file -oyaml
apiVersion: v1
data:
app.name: nginx
location.prefix: /app
kind: ConfigMap
metadata:
creationTimestamp: "2022-03-31T01:04:12Z"
name: cm-env-file
namespace: default
resourceVersion: "761496"
uid: 8e885d31-0a83-423c-a59f-6ea8b0473103
創建dp,並將cm掛在進去
[root@master01 yamls]# kubectl create deployment dp-test-cm --image=nginx --dry-run=client -oyaml > dp-test-cm.yaml
修改
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app: dp-test-cm
name: dp-test-cm
spec:
replicas: 1
selector:
matchLabels:
app: dp-test-cm
template:
metadata:
labels:
app: dp-test-cm
spec:
containers:
- image: nginx
name: nginx
env:
# 直接定義ENV的kv
- name: Level
value: Pro
# 將cm中的指定key的值作為AppName這個環境變數的值
- name: AppName
valueFrom:
configMapKeyRef:
name: cm-env-file
key: app.name
驗證:
[root@master01 yamls]# kubectl get po
NAME READY STATUS RESTARTS AGE
dp-test-cm-7c5666c5c4-wnhtk 1/1 Running 0 111s
[root@master01 yamls]# kubectl exec -ti dp-test-cm-7c5666c5c4-wnhtk -- sh
# echo $AppName
nginx
# echo $Level
Pro
1.2.2、envFrom
一次性配置多個環境變數
注意點:如果key不存在,不會影響pod的運用,但是也不會創建這個環境變數
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app: dp-test-cm
name: dp-test-cm
spec:
replicas: 1
selector:
matchLabels:
app: dp-test-cm
template:
metadata:
labels:
app: dp-test-cm
spec:
containers:
- image: nginx
name: nginx
# 和env同級,將redis-cm中的所有kv均作為環境變數注入到容器中
envFrom:
- configMapRef:
name: redis-cm
env:
- name: Level
value: Pro
- name: AppName
valueFrom:
configMapKeyRef:
name: cm-env-file
key: app.name
驗證:
[root@master01 yamls]# kubectl exec -ti dp-test-cm-6b7d8dc675-wf2vm -- sh
# echo $ip
10.10.10.101
1.2.3、volumeMounts
將基於文件創建的configMap以文件的形式掛在Pod的指定目錄中
關鍵字:volume、volumeMounts
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app: dp-test-cm
name: dp-test-cm
spec:
replicas: 1
selector:
matchLabels:
app: dp-test-cm
template:
metadata:
labels:
app: dp-test-cm
spec:
volumes:
- name: brm-config
configMap:
name: cm-from-file
containers:
- image: nginx
name: nginx
volumeMounts:
- name: brm-config
mountPath: "/etc/foo"
驗證:可以看到它會將ConfigMap.data中的每一項,都作為一個單獨的文件掛載進Pod中。
[root@master01 yamls]# kubectl get cm cm-from-file -oyaml
apiVersion: v1
data:
nginx.conf: |
app.name=nginx
location.prefix=/app
redis.conf: |
ip=10.10.10.101
port=2379
kind: ConfigMap
metadata:
creationTimestamp: "2022-03-31T00:52:21Z"
name: cm-from-file
namespace: default
resourceVersion: "759788"
uid: 5a41bdbe-66d0-45fa-8a5e-b6f6b005d671
[root@master01 yamls]# kubectl exec -ti dp-test-cm-68d77c6c6-4jtqr -- sh
# cd /etc/foo
# ls
nginx.conf redis.conf
# cat nginx.conf
app.name=nginx
location.prefix=/app
1.2.4、自定義文件名稱
自定義掛載進Pod容器的文件名關鍵字:spec.spec.volumes.configMap.items
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app: dp-test-cm
name: dp-test-cm
spec:
replicas: 1
selector:
matchLabels:
app: dp-test-cm
template:
metadata:
labels:
app: dp-test-cm
spec:
volumes:
- name: brm-config
configMap:
name: cm-from-file
items:
- key: redis.conf
path: redis.conf.cus
containers:
- image: nginx
name: nginx
volumeMounts:
- name: brm-config
mountPath: "/etc/foo"
1.2.5、控制文件許可權
關鍵字:spec.template.spec.vulumes.configMap.defaultMode
和spec.template.spec.vulumes.configMap.items.mode
用在控制掛載進Pod的文件的許可權,---
分別對應421(八進位)
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app: dp-test-cm
name: dp-test-cm
spec:
replicas: 1
selector:
matchLabels:
app: dp-test-cm
template:
metadata:
labels:
app: dp-test-cm
spec:
volumes:
- name: brm-config
configMap:
name: cm-from-file
items:
- key: redis.conf
path: redis.conf.cus
mode: 0111
defaultMode: 0666
containers:
- image: nginx
name: nginx
volumeMounts:
- name: brm-config
mountPath: "/etc/foo"
1.2.6、子目錄-subPath
關鍵字:subPath
subpath的作用是解決spec.template.spec.containers.volumeMounts.mountPath
的掛載覆蓋問題
意思就是說,如果mountPath
指定的是一個目錄,那麼k8s會用我們期望掛載進該目錄的文件覆蓋掉該目錄中已存在的文件,從而導致意外的結果。
解決方式如下的subPath,就是將cm 掛載成指定目錄+指定文件,覆蓋也是對指定目錄中的指定文件進行覆蓋,也就是下例中:將brm-config這個cm掛載進容器的/etc/foo/nginx.conf
文件(覆蓋也不會影響其他文件)。
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app: dp-test-cm
name: dp-test-cm
spec:
replicas: 1
selector:
matchLabels:
app: dp-test-cm
template:
metadata:
labels:
app: dp-test-cm
spec:
volumes:
- name: brm-config
configMap:
name: cm-from-file
items:
- key: redis.conf
path: redis.conf.cus
mode: 0111
defaultMode: 0666
containers:
- image: nginx
name: nginx
volumeMounts:
- name: brm-config
mountPath: "/etc/foo/nginx.conf"
subPath: "nginx.conf"
這裡可以做一個實驗,比如在掛在之前先搞一個/etc/foo/1.txt,然後分別用subpath和不用subpath兩種方式做掛載,對比/etc/foo/1.txt的是否被覆蓋的差異~
1.2.7、熱更新
cm中的值被編輯修改後,Pod中對應的掛載文件的值也會保持同步。
特殊情況:
env-from
和value-from
這種以環境變數的形式掛載進pod的cm,無法做到熱更新
subPath
也無法熱更新
1.2.8、不可變的cm
與Kind同級,設置參數immutable=true
即可
1.3、限制條件
- cm收NameSpace限制,只有在同一個NameSpace中的Pod才能引用她
- cm必須先於使用它的pod前創建
- 只有被apiserver管理的Pod的才能使用cm,靜態pod無法使用cm
二、Secret
Secret主要用戶保管私密數據,比如密碼、token、ssh keys等資訊。這些資訊直接放在鏡像中一是不方便動態變動,而是數據比較敏感,不安全。
可以通過三種方式使用Secret
- 通過掛在方式掛在Secret到Pod中使用它
- 通過
2.1、創建
2.1.1、from-file
# 創建文件
[root@master01 echo -n 'admin' > ./username.txt
[root@master01 echo -n 'qwerqwer123123' > ./password.txt
# 查看幫助文檔
[root@master01 secret-file]# kubectl create secret --help
# 基於file創建secret,使用generic創建出的Secret類型為Opaque
[root@master01 secret-file]# kubectl create secret generic db-user-info --from-file=./username.txt --from-file=./password.txt
secret/db-user-info created
查看
[root@master01 secret-file]# kubectl get secrets db-user-info -oyaml
apiVersion: v1
data:
password.txt: cXdlcnF3ZXIxMjMxMjM=
username.txt: YWRtaW4=
kind: Secret
metadata:
creationTimestamp: "2022-04-05T23:08:11Z"
name: db-user-info
namespace: default
resourceVersion: "837054"
uid: eabe607c-27fc-4611-92c6-fce4cc24f030
type: Opaque
data中的數據經base64加密存儲,可直接解密
[root@master01 secret-file]# echo "cXdlcnF3ZXIxMjMxMjM=" | base64 -d
qwerqwer123123
2.1.2、from-literal
基於字面意思上的命令行中指定好key和value創建Secret
[root@master01 secret-file]# kubectl create secret generic secret-from-literal --from-literal=username=admin --from-literal=passsword=123456
secret/secret-from-literal created
查看
[root@master01 secret-file]# kubectl get secrets secret-from-literal -oyaml
apiVersion: v1
data:
passsword: MTIzNDU2
username: YWRtaW4=
kind: Secret
metadata:
creationTimestamp: "2022-04-05T23:19:02Z"
name: secret-from-literal
namespace: default
resourceVersion: "838616"
uid: ebb95a99-8cbf-48fd-a651-60e12cd30110
type: Opaque
2.1.3、基於yaml文件創建
- 需要將data使用base64提前加密好,必須基於秘文創建
- 也可以使用stringData基於明文創建secret
apiVersion: v1
kind: Secret
metadata:
name: my-secret-from-yaml
namespace: default
type: Opaque
data:
username: YWRtaW4=
password: MWYyZDFlMmU2N2Rm
創建
[root@master01 secret-file]# kubectl apply -f secret-user-info.yaml
secret/my-secret-from-yaml created
查看
[root@master01 secret-file]# kubectl get secrets my-secret-from-yaml -o yaml
apiVersion: v1
data:
password: MWYyZDFlMmU2N2Rm
username: YWRtaW4=
kind: Secret
metadata:
annotations:
kubectl.kubernetes.io/last-applied-configuration: |
{"apiVersion":"v1","data":{"password":"MWYyZDFlMmU2NRm","username":"YWRW4="},"kind":"Secret","metadata":{"annotations":{},"name":"my-secret-from-yaml","namespace":"default"},"type":"Opaque"}
creationTimestamp: "2022-04-05T23:28:27Z"
name: my-secret-from-yaml
namespace: default
resourceVersion: "839971"
uid: eb3acb4d-edf2-4ac0-9373-e7a931a1a559
type: Opaque
基於明文創建
使用stringData
關鍵字可以基於明文創建,因為不安全所以不推薦。
apiVersion: v1
kind: Secret
metadata:
name: secret-basic-auth
type: kubernetes.io/basic-auth
stringData:
username: admin # kubernetes.io/basic-auth 類型的必需欄位
password: t0p-Secret # kubernetes.io/basic-auth 類型的必需欄位
2.1.4、from-env-file
用法和cm的from-env-file類似
[root@master01 secret-file]# cat ./secret-env-file.txt
username=admin
password=123456
[root@master01 secret-file]# kubectl get secrets secret-from-env -oyaml
apiVersion: v1
data:
password: MTIzNDU2
username: YWRtaW4=
kind: Secret
metadata:
creationTimestamp: "2022-04-05T23:39:47Z"
name: secret-from-env
namespace: default
resourceVersion: "841608"
uid: efaf7ad6-2ded-4544-93f8-5efabd2ca449
type: Opaque
2.2、實戰
2.2.1、配置阿里雲私有倉庫密鑰
給kubelet配置私有雲下載Docker鏡像的帳號密碼
# 查看幫助文檔
[root@master01 secret-file]# kubectl create secret docker-registry -h
# 將username、password、email修改成自己的
[root@master01 secret-file]# kubectl create secret docker-registry brm-alicloud-docker-secret --docker-username=xxxx --docker-password=xxx [email protected] --docker-server=registry.cn-hangzhou.aliyuncs.com
查看(data中的dockerconfigjson) 同樣可以使用base64解碼看到一個json串
[root@master01 secret-file]# kubectl get secrets brm-alicloud-docker-secret -oyaml
apiVersion: v1
data:
.dockerconfigjson: eyJhdXRocyI6eyJyZWdpc3RyeS5jbi1oYW5nemhvdS5hbGl5dW5jcy5jb20iOnsidXNlcm5hbWUiOiLmnLHmmIzmraYyMjMzIiwicGFzc3dvcmQiOiJxd2VyMTAxMC4uIiwiZW1haWwiOiI2NDY0NTAzMDhAcXEuY29tIiwiYXV0aCI6IjVweXg1cGlNNXEybU1qSXpNenB4ZDJWeU1UQXhNQzR1In19fQ==
kind: Secret
metadata:
creationTimestamp: "2022-04-06T00:04:17Z"
name: brm-alicloud-docker-secret
namespace: default
resourceVersion: "845134"
uid: 6e7bd04e-621c-4da8-8649-99c0ebffcee9
type: kubernetes.io/dockerconfigjson
掛載,先搞一個模版dp
[root@master01 secret-file]# kubectl create deployment alicloud-private-nginx --image=registry.cn-hangzhou.aliyuncs.com/changwu/nginx:1.7.9-nettools --dry-run=client -oyaml
修改添加imagePullSecrets
配置
apiVersion: apps/v1
kind: Deployment
metadata:
creationTimestamp: null
labels:
app: alicloud-private-nginx
name: alicloud-private-nginx
spec:
replicas: 1
selector:
matchLabels:
app: alicloud-private-nginx
strategy: {}
template:
metadata:
creationTimestamp: null
labels:
app: alicloud-private-nginx
spec:
imagePullSecrets:
- name: brm-alicloud-docker-secret
containers:
- image: registry.cn-hangzhou.aliyuncs.com/changwu/nginx:1.7.9-nettools
name: nginx
resources: {}
status: {}
驗證的話就去 kubectl get pod -owide
即可
2.2.2、管理https證書
生成私鑰和crt
[root@master01 https]# openssl req -x509 -nodes -days 3650 \
> -newkey rsa:2048 -keyout tls.key -out tls.crt -subj "/CN=test.com"
Generating a 2048 bit RSA private key
....................................................................+++
...........+++
writing new private key to 'tls.key'
-----
[root@master01 https]# ls
tls.crt tls.key
將key和cry託管進secret
[root@master01 https]# kubectl create secret tls https-nginx-tls-test-secret -n default --key=tls.key --cert=tls.crt
secret/https-nginx-tls-test-secret created
查看
[root@master01 https]# kubectl get secrets https-nginx-tls-test-secret -oyaml
apiVersion: v1
data:
tls.crt: LS0tLS1CRUdJTiBDRVJUSUZJQ0FURS0tLS0tCk1R1lrWTJRCjN4VUpQV1hVR0lqM2VVYnhTc0hFZ2lyZDlJalBZL1pwZEsxWittbmNHTWMyNW41aVhoUEs1UG1ZcjYrcAotLS0tLUVORCBDRVJUSUZJQ0FURS0tLS0tCg==
tls.key: LS0tLS1CRUdJTiBQUklWQVRFIEtFWS0tLS0tCk1V3AzbUtRNHJkZG1CZGplMjJpMjR1bU5IUGd2STJBRGlEalAKNXBTb2hRYWRkZVZYRDJFZWdlWFRTTHY3Ci0tLS0tRU5EIFBSSVZBVEUgS0VZLS0tLS0K
kind: Secret
metadata:
creationTimestamp: "2022-04-06T00:25:33Z"
name: https-nginx-tls-test-secret
namespace: default
resourceVersion: "848213"
uid: afa127bb-4a3a-4eb9-9d55-8cd50af5b3f4
type: kubernetes.io/tls
配置到ingress中(不是很推薦直接在ingress中配置https,通常會將https配置在ingress的上一層的SLB代理中)
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: simple-tls-ingress
spec:
ingressClassName: nginx
rules:
- host: https-test.com # 配置域名,可以不寫,匹配*,或者寫 *.bar.com
http:
paths: # 相當於nginx的location,同一個host可以配置多個path
- path: /
pathType: Prefix
backend:
service:
name: nginx-svc
port:
number: 80
tls:
- secretName: https-nginx-tls-test-secret
驗證
2.2.3、不可變的secret
與Kind同級,設置參數immutable=true
即可