[invoker] set the WaitDelay to avoid getting indefinitely blocking wait()

[acabarbaye]

Describe the bug

The problem lies in how the commands are spawned in the Invoker

gopsutil/internal/common/common.go

Line 50 in 6100124

cmd := exec.CommandContext(ctx, name, arg...)

if the spawned command opens I/Os, the wait() could block indefinitely. This bug has been reported in many issues with go : golang/go#24050 golang/go#20730 golang/go#23019 golang/go#56187 golang/go#57129 golang/go#60309 golang/go#22485

A solution is to set the WaitDelay to ensure wait() returns

// If WaitDelay is non-zero, the command's I/O pipes will be closed after
// WaitDelay has elapsed after either the command's process has exited or
// (if Context is non-nil) Context is done, whichever occurs first.
// If the command's process is still running after WaitDelay has elapsed,
// it will be terminated with os.Kill before the pipes are closed.
//
// If the command exits with a success code after pipes are closed due to
// WaitDelay and no Interrupt signal has been sent, Wait and similar methods
// will return ErrWaitDelay instead of nil.
//
// If WaitDelay is zero (the default), I/O pipes will be read until EOF,
// which might not occur until orphaned subprocesses of the command have
// also closed their descriptors for the pipes.
WaitDelay time.Duration

To Reproduce
the following should block indefinitely

common.Invoke{}.Command("bash", "-c", "watch date > date.txt 2>&1")

Expected behavior
The command above should be terminated if the Timeout is exceeded

Environment (please complete the following information):

• Windows: [paste the result of ver]
• Linux: [paste contents of /etc/os-release and the result of uname -a]
• Mac OS: [paste the result of sw_vers and uname -a
• FreeBSD: [paste the result of freebsd-version -k -r -u and uname -a]
• OpenBSD: [paste the result of uname -a]

Additional context
[Cross-compiling? Paste the command you are using to cross-compile and the result of the corresponding go env]

[shirou]

That is why we introduced xxxWithContext. We can avoid waiting indefinitely by setting a timeout for a context . Further, as the author of the library, we cannot set the appropriate wait time. Therefore, we provide a way for library users to set a timeout.