为什么我的 Kubernetes pods 共享环境变量?

Why are my Kubernetes pods sharing environment variables?

我有 3 个,完全不同,pods:

kubectl get pods -o go-template --template '{{range .items}}{{.metadata.name}}{{"\n"}}{{end}}'
kubernetes-bootcamp-5c69669756-5rh9t
queenly-seahorse-mysql-6dc964999c-h4w54
wordpress-mysql-bcc89f687-hs677

但它们似乎共享相同的环境变量。例如。

kubectl exec "kubernetes-bootcamp-5c69669756-5rh9t" env | grep MYSQL
QUEENLY_SEAHORSE_MYSQL_PORT_3306_TCP=tcp://10.98.170.14:3306
QUEENLY_SEAHORSE_MYSQL_SERVICE_PORT_MYSQL=3306
QUEENLY_SEAHORSE_MYSQL_PORT_3306_TCP_ADDR=10.98.170.14
QUEENLY_SEAHORSE_MYSQL_SERVICE_HOST=10.98.170.14
QUEENLY_SEAHORSE_MYSQL_SERVICE_PORT=3306
QUEENLY_SEAHORSE_MYSQL_PORT=tcp://10.98.170.14:3306
QUEENLY_SEAHORSE_MYSQL_PORT_3306_TCP_PORT=3306
QUEENLY_SEAHORSE_MYSQL_PORT_3306_TCP_PROTO=tcp

然后在一个完全不同的、不相关的 pod 上(但在同一个节点上):

kubectl exec "queenly-seahorse-mysql-6dc964999c-h4w54" env | grep MYSQL
MYSQL_ROOT_PASSWORD=<redact>
MYSQL_PASSWORD=<redact>
MYSQL_USER=
MYSQL_DATABASE=
QUEENLY_SEAHORSE_MYSQL_PORT=tcp://10.98.170.14:3306
QUEENLY_SEAHORSE_MYSQL_PORT_3306_TCP=tcp://10.98.170.14:3306
QUEENLY_SEAHORSE_MYSQL_PORT_3306_TCP_PORT=3306
QUEENLY_SEAHORSE_MYSQL_PORT_3306_TCP_ADDR=10.98.170.14
QUEENLY_SEAHORSE_MYSQL_SERVICE_PORT=3306
QUEENLY_SEAHORSE_MYSQL_SERVICE_HOST=10.98.170.14
QUEENLY_SEAHORSE_MYSQL_SERVICE_PORT_MYSQL=3306
QUEENLY_SEAHORSE_MYSQL_PORT_3306_TCP_PROTO=tcp
MYSQL_MAJOR=5.7
MYSQL_VERSION=5.7.14-1debian8

有什么解释吗?

FWIW,我显然 exec 正在进入 2 个不同的 pods。例如

kubectl exec "queenly-seahorse-mysql-6dc964999c-h4w54" env | grep HOSTNAME
HOSTNAME=queenly-seahorse-mysql-6dc964999c-h4w54

kubectl exec "kubernetes-bootcamp-5c69669756-5rh9t" env | grep HOSTNAME
HOSTNAME=kubernetes-bootcamp-5c69669756-5rh9t

我删除了我的评论并将其添加为答案。我意识到 Kubernetes 已经为名为 "queenly-seahorse-mysql" 的服务添加了 "QUEENLY_SEAHORSE_MYSQL_xxxx" 环境变量 - 请参阅 https://kubernetes.io/docs/concepts/services-networking/service/#environment-variables

所有 Kubernetes 服务环境变量都在命名空间中共享。这是设计使然 pods 可以在需要时找到特定的服务。

已经 discussions 关于如何禁用它们,但我相信上游还没有添加修复程序。