一直被此问题困扰，google后找到解决方案：

I had this annoying issue where Android Studio kept deleting my top-level project file (.iml) whenever I do a gradle sync. For months I had no idea why and Google search doesn’t seem to show this as a common issue. Finally today I got to the bottom of this.

The issue was the casing of the file names. For the project file, I had mixed capital and lowercase, whereas the project folder name was all lowercase. This inconsistency was due to a move of the project from a windows environment to a mac where I had a different folder name.

The fix for this issue was simple: Close the project in Android Studio and delete all the .iml files. Then use File > Import project and select the project folder and this will regenerate all the .iml files. The new .iml files should now match the case of the folder.

问题排查：
kubectl describe pods xxx
显示 Error syncing pod, skipping: failed to “StartContainer” for “POD” with ErrImagePull: “image pull failed for registry.access.redhat.com/rhel7/pod-infrastructure:latest, this may be because there are no credentials on this request. details: (open /etc/docker/certs.d/registry.access.redhat.com/redhat-ca.crt: no such file or directory)”
ll -h /etc/docker/certs.d/registry.access.redhat.com/redhat-ca.crt 显示指向 /etc/rhsm/ca/redhat-uep.pem
/etc/rhsm/ca/redhat-uep.pem 不存在导致问题

解决问题：
网上解决方案 yum install python-rhsm-certificates 现在失效了 Package python-rhsm-certificates-1.19.10-1.el7_4.x86_64 is obsoleted by subscription-manager-rhsm-certificates-1.20.11-1.el7.centos.x86_64 which is already installed
需要手动下载和生成pem
wget http://mirror.centos.org/centos/7/os/x86_64/Packages/python-rhsm-certificates-1.19.10-1.el7_4.x86_64.rpm
rpm2cpio python-rhsm-certificates-1.19.10-1.el7_4.x86_64.rpm | cpio -iv –to-stdout ./etc/rhsm/ca/redhat-uep.pem | tee /etc/rhsm/ca/redhat-uep.pem