Kubernetes yaml部署-无法创建符号链接

Question

我正在尝试进行nginx部署，在创建容器的过程中，我想创建多个符号链接。但由于某种原因，它不起作用，容器崩溃了。

apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app: tcc
component: nginx
name: tcc-nginx-deployment
namespace: dev2
spec:
replicas: 1
selector:
matchLabels:
app: tcc
component: nginx
template:
metadata:
labels:
app: tcc
component: nginx
spec:
containers:
- image: nginx
name: nginx
command:
- /bin/sh
- -c
- |
ln -s /shared/apps/ /var/www
rm -r /etc/nginx/conf.d
ln -s /shared/nginx-config/ /etc/nginx/conf.d
ports:
- containerPort: 80
protocol: TCP
volumeMounts:
- mountPath: /shared
name: efs-pvc
volumes:
- name: efs-pvc
persistentVolumeClaim:
claimName: tcc-efs-storage-claim

Answer 1

容器没有运行，因为在执行command块之后，容器正在退出，这是预期的行为。

与其在yaml模板中使用command中的符号链接(这不是最佳实践解决方案(，为什么不使用Kubernetes内置的解决方案，并且根本不使用command块？

您应该使用subPath，它旨在为单个pod上的多个不同目录共享一个卷中的目录：

有时，在单个pod中共享一个卷用于多种用途是很有用的。volumeMounts.subPath属性指定引用卷内的子路径，而不是其根路径。

在您的情况下，部署yaml应该如下所示：

apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app: tcc
component: nginx
name: tcc-nginx-deployment
namespace: dev2
spec:
replicas: 1
selector:
matchLabels:
app: tcc
component: nginx
template:
metadata:
labels:
app: tcc
component: nginx
spec:
containers:
- image: nginx
name: nginx
ports:
- containerPort: 80
protocol: TCP
volumeMounts:
- mountPath: /shared
name: efs-pvc
- mountPath: /etc/nginx/conf.d
name: efs-pvc
subPath: nginx-config
- mountPath: /var/www
name: efs-pvc
subPath: apps
volumes:
- name: efs-pvc
persistentVolumeClaim:
claimName: tcc-efs-storage-claim

此外，如果您只想装载NGINX的配置文件，您可以使用ConfigMap而不是卷-请查看此答案以了解更多信息。

Answer 2

• 这是因为您要求容器只创建符号链接。因此，一旦创建了这些
  符号链接，容器就会退出。

• 为了避免这种情况，添加"nginx" "-g" "daemon off;"如下：

apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app: tcc
component: nginx
name: tcc-nginx-deployment
spec:
replicas: 1
selector:
matchLabels:
app: tcc
component: nginx
template:
metadata:
labels:
app: tcc
component: nginx
spec:
containers:
- image: nginx
name: nginx
imagePullPolicy: IfNotPresent
command:
- /bin/sh
- -c
- |
ln -s /shared/apps/ /var/www
rm -r /etc/nginx/conf.d
ln -s /shared/nginx-config/ /etc/nginx/conf.d
"nginx" "-g" "daemon off;" ; # after creating above symbolic links it will start nginx daemon 
ports:
- containerPort: 80
protocol: TCP
volumeMounts:
- mountPath: /shared
name: efs-pvc
volumes:
- name: efs-pvc
persistentVolumeClaim:
claimName: tcc-efs-storage-claim