Failed to validate windows-system-stats-monitor.json configuration: ProcPath /proc check failed

[mmiranda96]

I noticed this issue when I was running NPD on Windows: when trying to run systemstatsmonitor, I get the following failure:

Failed to validate C:\node-problem-detector\config\windows-system-stats-monitor.json configuration [BIG JSON]: ProcPath /proc check failed: CreateFile /proc: The system cannot find the file specified.

After digging for a while, I found that this failure comes from

node-problem-detector/pkg/systemstatsmonitor/types/config.go

Line 138 in 6e57ca6

if _, err := os.Stat(ssc.ProcPath); err != nil {

It seems that we try to check the proc file on all platforms, and this is a problem because it doesn't apply for Windows.

This change was introduced in #594.

There are a couple of fixes I can think of:

• Entirely removing the check: simplest fix, could cause an issue if the user provides a wrong directory.
• Disabling the default /proc value (

  node-problem-detector/pkg/systemstatsmonitor/types/config.go

  Line 111 in 6e57ca6

  ssc.ProcPath = defaultProcPath

  ) and skipping the check if it's empty: will fail if user doesn't explicitly provide a directory.
• Defining a specific value to skip validation (something like "undefined"): depending on a magic string is not always a good idea, and this value is kind of arbitrary.
• Splitting validation logic between Windows and Linux: requires splitting logic but is the cleanest option.

[mmiranda96]

/kind bug
/priority important-soon
/cc @CoderSherlock

[samuelkarp]

Disabling the default /proc value

We can also conditionally have a default value based on the operating system. This can be done by a conditional with runtime.GOOS or by moving the declaration out to two separate files (a config_linux.go and a config_windows.go).

if runtime.GOOS == "linux" && ssc.ProcPath == "" {
	ssc.ProcPath = defaultProcPath
}