25e3a961c3
When the initial DeleteVolume times out (as it does on slow clusters due to the low 10 second limit), the external-provisioner calls it again. The CSI standard requires the second call to succeed if the volume has been deleted in the meantime. This didn't work because DeleteVolume returned an error when failing to find the volume info file: rbdplugin: E1008 08:05:35.631783 1 utils.go:100] GRPC error: rbd: open err /var/lib/kubelet/plugins/csi-rbdplugin/controller/csi-rbd-622a252c-cad0-11e8-9112-deadbeef0101.json/open /var/lib/kubelet/plugins/csi-rbdplugin/controller/csi-rbd-622a252c-cad0-11e8-9112-deadbeef0101.json: no such file or directory The fix is to treat a missing volume info file as "volume already deleted" and return success. To detect this, the original os error must be wrapped, otherwise the caller of loadVolInfo cannot determine the root cause. Note that further work may be needed to make the driver really resilient, for example there are probably concurrency issues. But for now this fixes: #82
2.2 KiB
errors 
Package errors provides simple error handling primitives.
go get github.com/pkg/errors
The traditional error handling idiom in Go is roughly akin to
if err != nil {
return err
}
which applied recursively up the call stack results in error reports without context or debugging information. The errors package allows programmers to add context to the failure path in their code in a way that does not destroy the original value of the error.
Adding context to an error
The errors.Wrap function returns a new error that adds context to the original error. For example
_, err := ioutil.ReadAll(r)
if err != nil {
return errors.Wrap(err, "read failed")
}
Retrieving the cause of an error
Using errors.Wrap constructs a stack of errors, adding context to the preceding error. Depending on the nature of the error it may be necessary to reverse the operation of errors.Wrap to retrieve the original error for inspection. Any error value which implements this interface can be inspected by errors.Cause.
type causer interface {
Cause() error
}
errors.Cause will recursively retrieve the topmost error which does not implement causer, which is assumed to be the original cause. For example:
switch err := errors.Cause(err).(type) {
case *MyError:
// handle specifically
default:
// unknown error
}
Read the package documentation for more information.
Contributing
We welcome pull requests, bug fixes and issue reports. With that said, the bar for adding new symbols to this package is intentionally set high.
Before proposing a change, please discuss your change by raising an issue.
Licence
BSD-2-Clause