In NodeHealthScriptRunner method, we will set HealthChecker status based on the Shell execution results. Some status are based on the exception thrown during the Shell script execution.
Currently, we will catch a non-ExitCodeException from ShellCommandExecutor, and if Shell has the timeout status set at the same time, we will also set HealthChecker status to timeout.
We have following execution sequence in Shell:
1) In main thread, schedule a delayed timer task that will kill the original process upon timeout.
2) In main thread, open a buffered reader and feed in the process's standard input stream.
3) When timeout happens, the timer task will call Process#destroy()
to kill the main process.
On Linux, when timeout happened and process killed, the buffered reader will thrown an IOException with message: "Stream closed" in main thread.
On Windows, we don't have the IOException. Only "-1" was returned from the reader that indicates the buffer is finished. As a result, the timeout status is not set on Windows, and TestNodeHealthService fails on Windows because of this.