第7关 k8s架构师课程之配置管理
大家好，我是博哥爱运维，K8s是如何来进行服务配置管理的呢？这节课博哥带大家来攻克这关。
[]https://github.com/bogeit/LearnK8s/blob/main/%E7%AC%AC7%E5%85%B3%20k8s%E6%9E%B6%E6%9E%84%E5%B8%88%E8%AF%BE%E7%A8%8B%E4%B9%8B%E9%85%8D%E7%BD%AE%E7%AE%A1%E7%90%86.md
Configmap, secret
对于容器而言，如果我们想修改一个容器镜像里面的配置，可以在Dockerfile这一步，将修改好的配置复制到镜像里面再重新打包，对于不用变动配置的镜像而言，这样做属于硬编码当然也可以，但一旦我们的镜像服务需要修改配置，那么就需要重新重新打包非常麻烦，对于K8s而言，对于配置这么重要的一个环节，自然有它的解决方案，那就是configmap（通常普通配置使用）和secret（对于一些机密配置信息使用），在上面的部分章节里面，有提前涉及到这部分内容，但没有进行仔细的讲解，这里就对它们作下详细的实践。
我这里会准备一个deployment的yaml配置，用busybox来作为服务镜像，通过一个完整的yaml就可以快速带你们理解并能熟练在K8s上使用configmap和secret，如果一下子理解不了，后面可以保存这份yaml来作来生产配置参考也是没问题的，用多了自然就熟了，yaml配置如下：
configmap-secret-example-simple.yaml
---
# configmap
# kubectl create configmap localconfig-env --from-literal=log_level_test=TEST --from-literal=log_level_produce=PRODUCE
apiVersion: v1
kind: ConfigMap
metadata:
name: localconfig-env
data:
log_level_test: TEST
log_level_produce: PRODUCE
---
# configmap
# kubectl create configmap localconfig-file --from-file=localconfig-test=localconfig-test.conf --from-file=localconfig-produce=localconfig-produce.conf
apiVersion: v1
kind: ConfigMap
metadata:
name: localconfig-file
data:
localconfig-produce: |
TEST_RELEASE = False
PORT = 80
PROCESSES = 0
MESSAGE = Produce
localconfig-test: |
TEST_RELEASE = True
PORT = 8080
PROCESSES = 1
MESSAGE = Test
---
# secret
# kubectl create secret generic mysecret --from-literal=mysql-root-password='!QAZ2wsx' --from-literal=redis-root-password='!2Boge' --from-file=my_id_rsa=/root/.ssh/id_rsa --from-file=my_id_rsa_pub=/root/.ssh/id_rsa.pub
apiVersion: v1
kind: Secret
metadata:
name: mysecret
namespace: default
type: Opaque
data:
my_id_rsa: LS0tLS1CRUdJTiBSU0EgUFJJVkFURSBLRVktLS0tLQpNSUlFb3dJQkFBS0NBUEVBdG1jMjc0ZnBCOE5rNHNkMGhVYktKcVVjMnZpQUEveTIycUpvME5sVmtOalJtMDNpCmZTbEl6QUtZOWNLWmhxazhWM2lEeW1WSjVUcHM2QXZxK1dtWDMrbTlwS05icEgvOE1tTHk1cG1EaXdoUDNHdzAKeldaeFBmQXZhU2VCcGlwMTBmTmV4TWJUVXdCNjUrU01MSHN4QVlKZnBvS2ZaVDN1TVZpVHhzbWFQNUp2bmpCVgpMdUpVZXpKak4rcTByQjl1Mng5NnI3d1dlcGJSeGx0TmxoUlBhblpxMnJVSEU2Z3BlbjAxYTR3RGhZZU0zZkhWCm1qMnRTYjJUQXlGRjBQdXViNTJZWFhsMXpqdnNVMGNUMCtCcDNTSFlVTkdBZjVab2UxaW83QkZwSHR1TFdWZksKbnowR1cwUDBxK3NTM1VLTHlqaXN5aEYvR0Z4MlA3cjBhYmVYMXdJREFQQUJBb0lCQUFMME01b2JqUG9CaDF1MQpsUCtYdHlSQkJlQ1lVZCs5MDFJcGpWRFNodTVqWjFYaTBzajZDWlNadGFDU0RhcDBqK2tJZ1g1cmNHZUdMb2FqCktFb054Ymc3OEI3SUpIQ3pSejIvSjkxRUh6SFVQdVkxQTBWRmZoaGx5VlRrdHFuSG5XWDJ5RTVlZ0lHV1VFMmcKeGtjbzNlZ1lDVUNXWWIwODVwejdyOG91NzZCcXFZY1oyQVJGZWx1VjZ1ODZyajIzeG1QcGtvaFBLQS9QdERxSApsdmN1cDVHRFkxQ2NNMHFwRXJXejN6NTE4UjYzN1BNQ3hJM2VDaXAwMGhMMDJZdFkva2tvYUhnSHdpRWNYRXowCjhGeHpxR1BUc2VSQnBwcWlTaXh1a1Bjb285b1BuRVhnN25pVGI2VitCMUxZVmdjejVsQlQ0WEZQR1dNYlB6aGMKN0FXNjBBRUNnWUVBMlJQeGpYYThNZkQ5ZnhnVDdha01yZGVpanBETGt3VVVySm5KNVAycWErR1VQSld1N1RhUAozR3RFc0FoSE5VVlJKbHFzYUFJM2hhTGZsSysrSVdQZ3dJaWh2TTVLcnVHdjNzYmFudEltZUpkZmNlTjBqdHR6CmRKc3FFMHorajZ0YkdsNHNDek0wUmJyUEdxN3gwa0lTTkFpWXg3cUIzcUlBVGRkWHArRjVVRmNDZ1lFQTF4dHMKdC9Hc2xBd3JHN1RER2paZTZyNXJDQlloTGlJREptSjBsWXNNdnV1d01WRlcrNjNjQkRvL1pFbVNIbFpMMFhNVwp6dlRUV2x1WHpVTm9HQytDSWk1dDAwaUZsL2tlL3dVcG5qZnhtZm1NRHhNUkN2YzJESlRSeDAzaldzd0U3WTRxCnBLQ0dENTZyQW1hMms2VGJvKzBiWWJZRzBLb0JKM3lyVS94WlJJRUNnWUVBeTh6Qm0wWllXU3EvVTRydmFyakQKUnBLajh1VE51d0dTSDFsaXlzREJ0dmJaajBlYWl1b210ZkdmVXdUeWxYaTJieVBCcVBQcnpETFZaV3A1UGkvZQoyZU5zdFMyWHdBZnliVnlUODNlbzFwNkc1UDErYUlCdkxKSmdNL1BNS21YZDZpdHZmalA0dWc1aFBpdnNIWjNhCktTL0kvL3FCNHRxRkhvK0ZvLzl6UFpFQ2dZQTVQSGhnUFBlZzg5Z3BhS1BnL3VXbWJ3WUh3ZlBVMWtLbVhjQVAKNlZGOEl6amk5M1pDU0ZUdDN4N3VMMUt2dG1JNW5mc3RIQ2FBdnk0WkdON0V5U2hHdHJxbFVlWDB1LzYwKzYzSApDYmJKTjQwYW1nV0kwS0h2R1ZENFRmZTgwOTczNTBYY1NVbEZNUEx0QWErSWZuRmpIbnBGdUcvNTY3V2c3K0tkCjIwVmRnUEtCZ0UrK1BZRUZKK2ZQeGtMeFRweUw5MDVHSVBBS00wM0MzV2J6b0lzSEZzbXZObWN6V2piK2hTWGsKTmVVZ0VNSnhjNytDN21LckkxZEcweFhVcVhqM1dvMjVxY0ZQUFYrMHZ1UmVnWk10aStpTW1zcTUyR29Xdld4egpVbmhpdnpyOXFsV0lzeHVzdTZjbzdxZ1gxeHl5L2d2SGxWYWdrR1hHZi9iSEtqZmVYeHdHCi0tLS0tRU5EIFJTQSBQUklWQVRFIEtFWS0tLS0tCg==
my_id_rsa_pub: 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
mysql-root-password: IVFBWjJ3c3g=
redis-root-password: ITJCb2dl
---
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
run: test-busybox
name: test-busybox
namespace: default
spec:
replicas: 1
selector:
matchLabels:
run: test-busybox
template:
metadata:
labels:
run: test-busybox
spec:
containers:
- name: test-busybox
image: busybox
args:
- /bin/sh
- -c
- >
echo "-------------------------------------------------";
echo "TEST_ENV is:$(TEST_ENV)";
echo "-------------------------------------------------";
echo "PRODUCE_ENV is:$(PRODUCE_ENV)";
echo "-------------------------------------------------";
echo "secret MYSQL_ROOT_PASSWORD is:$(MYSQL_ROOT_PASSWORD)";
echo "-------------------------------------------------";
echo "secret REDIS_ROOT_PASSWORD is:$(REDIS_ROOT_PASSWORD)";
echo "-------------------------------------------------";
echo "/etc/local_config_test.py body is:";
cat /etc/local_config_test.py;
echo "-------------------------------------------------";
echo "/etc/local_config_produce.py body is:";
cat /etc/local_config_produce.py;
echo "-------------------------------------------------";
echo "/etc/id_rsa body is:";
cat /etc/id_rsa;
echo "-------------------------------------------------";
echo "/etc/id_rsa.pub body is:";
cat /etc/id_rsa.pub;
echo "-------------------------------------------------";
ls -ltr /etc;
sleep 30000;
env:
- name: TEST_ENV
valueFrom:
configMapKeyRef:
name: localconfig-env
key: log_level_test
- name: PRODUCE_ENV
valueFrom:
configMapKeyRef:
name: localconfig-env
key: log_level_produce
- name: MYSQL_ROOT_PASSWORD
valueFrom:
secretKeyRef:
name: mysecret
key: mysql-root-password
- name: REDIS_ROOT_PASSWORD
valueFrom:
secretKeyRef:
name: mysecret
key: redis-root-password
volumeMounts:
- name: testconfig
mountPath: "/etc/local_config_test.py"
subPath: localconfig-test
- name: testconfig
mountPath: "/etc/local_config_produce.py"
subPath: localconfig-produce
readOnly: true
- name: testsecret
mountPath: "/etc/id_rsa"
subPath: my_id_rsa
readOnly: true
- name: testsecret
mountPath: "/etc/id_rsa.pub"
subPath: my_id_rsa_pub
readOnly: true
volumes:
- name: testconfig
configMap:
name: localconfig-file
defaultMode: 0660
- name: testsecret
secret:
secretName: mysecret
defaultMode: 0600volumeMounts是只pod要挂载的目录是/etc/local_config_test.py，实际的磁盘挂载目录是在volumes中指定的，在volumes中和configMap进行绑定，/etc/local_config_test.py实际挂载的点
是localconfig-file，这里localconfig-file是configmap的名字，但是etc/local_config_test.py实际和localconfig-file这个configmap中那个具体的文件对应的，是有subpath来决定的
mountPath: "/etc/local_config_test.py"
subPath: localconfig-test这里本质上就是将localconfig-file这个configmap中localconfig-test的内容写入到/etc/local_config_test.py文件中
apiVersion: v1
kind: ConfigMap
metadata:
name: localconfig-file
data:
localconfig-produce: |
TEST_RELEASE = False
PORT = 80
PROCESSES = 0
MESSAGE = Produce
localconfig-test: |
TEST_RELEASE = True
PORT = 8080
PROCESSES = 1
MESSAGE = Test
/etc/local_config_test.py文件中的内容如下
TEST_RELEASE = True
PORT = 8080
PROCESSES = 1
MESSAGE = Testpod启动成功之后，就可以访问/etc/local_config_test.py文件内容了
， readOnly: true表示pod不能够改变挂载点的内容，不能在pod中修改/etc/local_config_test.py文件的内容
defaultMode: 0600是值指/etc/local_config_test.py在要挂载容器内部的文件的权限
/etc/local_config_test.py