When runC shimv2 starts, the StartShim interface will re-exec itself as
long-running process, which will read the `address` during initializing.
```happycase
Process
containerd-shim-runc-v1/v2 start containerd-shim-runc-v1/v2
initializing socket
reexec containerd-shim-runc-v1/v2
write address into file
initializing
read address
write back to containerd daemon
serving
...
remove address in Shutdown call
```
However, there is no synchronization after reexec. Then the data race is
like:
```leaking-case
Process
containerd-shim-runc-v1/v2 start containerd-shim-runc-v1/v2
initializing socket
reexec containerd-shim-runc-v1/v2
initializing
read address
write address into file
write back to containerd daemon
serving
...
fail to remove address
because of empty address
```
The `address` should be writen into file first before reexec.
And if shutdown the whole service before cleanup temporary
resource (like socket file), the Shutdown caller will receive `ttrpc: closed`
sometime, which depends on go runtime scheduler. Then it also causes leaking
socket files.
Since the shimV2-Delete binary API must be called to cleanup shim temporary
resource and shimV2-runC-v1 doesn't support grouping multi containers in one,
it is safe to remove the socket file in the binary call for shimV2-runC-v1.
But for the shimV2-runC-v2 shim, we still cleanup socket in Shutdown.
Hopefully we can find a way to cleanup socket in shimV2-Delete binary
call.
Fix: #5173
Signed-off-by: Wei Fu <fuweid89@gmail.com>
d895118c7c