The changes to gopsutil for reading /proc/1/mountinfo affected
applications running under restricted environments that disallows access
to /proc/1/mountinfo. #1159 was filed for android but other restricted
environments are also affected (eg, snaps)). The fix for #1159 addressed
the application behavior to work under confinement for non-android as
well. However, depending on the system, the attempt to read
/proc/1/mountinfo could cause a sandbox denial in the logs which can be
quite noisy if using gopsutil as part of a monitoring solution that
polls often.
This introduces HOST_PROC_MOUNTINFO to force reading from the parent dir
of the specified path instead of first trying /proc/1. When unset,
retain the current behavior with fallback. This allows people, for
example, to set HOST_PROC_MOUNTINFO=/proc/self/mountinfo when gopsutil
is running under these restricted environments.
This change updates the private readMountFile() to use a root path
instead of a root subpath, and adjusts PartitionsWithContext() to set
the root path to /proc/1 initially and falling back to /proc/self. When
HOST_PROC_MOUNTINFO is not empty, set the root path to the parent
directory of HOST_PROC_MOUNTINFO.
Jamie Strandboge