nodemgr doesn't handle "pipe" core_pattern properly

[Krzysztof Klimonda]

/proc/sys/kernel/core_pattern can start with a | (pipe) symbol, in which case it's parsed as a userspace script that will process the core file. If that's the case, the location of core files is implementation specific.

Add support for a DEFAULT.corefile_path config variable that lets operators specify a path to the directory with coredump files.

[OpenContrail Admin (ci-admin-f)]

Review in progress for https://review.opencontrail.org/35676
Submitter: Krzysztof Klimonda (<email address hidden>)

[OpenContrail Admin (ci-admin-f)]

Reviewed: https://review.opencontrail.org/35676
Committed: http://github.com/Juniper/contrail-controller/commit/f37c936440f883b936929e2cfc3e6e42eb260b02
Submitter: Zuul (<email address hidden>)
Branch: master

commit f37c936440f883b936929e2cfc3e6e42eb260b02
Author: Krzysztof Klimonda <email address hidden>
Date: Fri Sep 15 09:41:47 2017 +0200

Make corefile_path variable adjustable.

When the first character of /proc/sys/kernel/core_pattern file
is a | symbol, the remainder of the line is to be interpreted
as a command-line to a userspace script that will process the
coredump file. In that case we cannot parse that line and assume
it will point to the location of system core files. Instead, allow
operators to specify where core files are located.

Closes-Bug: #1717862
Change-Id: Ibbde444fdf555dccba41c8c9e26846f2570e4e7b