[00/11] introduce telemetry library

  This patchset introduces a Telemetry library for DPDK Service Assurance.
This library provides an easy way to query DPDK Ethdev metrics.

The telemetry library provides a method for a service assurance component
to retrieve metrics from a DPDK packet forwarding application.
Communicating from the service assurance component to DPDK is done using
a UNIX domain socket, passing a JSON formatted string. A reply is
sent (again a JSON formatted string) of the current DPDK metrics.

The telemetry component makes use of the existing rte_metrics library to
query values. The values to be transmitted via the telemetry infrastructure
must be present in the Metrics library. Currently the ethdev values are
pushed to the metrics library, and the queried from there – there is an
open question on how applications would like this to occur. Currently only
ethdev to metrics functionality is implemented, however other subsystems
like crypto, eventdev, keepalive etc can use similar mechanisms.

Exposing DPDK Telemetry via a socket interface enables service assurance
agents like collectd to consume data from DPDK. This is vital for
monitoring, fault-detection, and error reporting. A collectd plugin has
been created to interact with the DPDK Telemetry component, showing how it
can be used in practice. The collectd plugin patch can be found at
lib/librte_telemetry/collectd_plugin/v1-0001-dpdk_telemetry-add-plugin-
for-DPDK-metrics-via-DP.patch, this will be upstreamed to collectd at a
later stage. Further instructions on applying the collectd patch can be
found in the collectd patch commit message. A small python script is
provided in ./usertools/telemetry_client.py to quick-start using
DPDK Telemetry.

Ciara Power and Brian Archbold (10):
  telemetry: initial telemetry infrastructure
  telemetry: add initial connection socket
  telemetry: add client feature and sockets
  telemetry: add parser for client socket messages
  telemetry: update metrics before sending stats
  telemetry: format json response when sending stats
  telemetry: add tests for telemetry api
  telemetry: add vdev kvargs for selftest
  doc: add telemetry documentation
  usertools: add client python script for telemetry

Emma Kenny (1) :
  telemetry: add collectd plugin patch

 config/common_base                                 |    5 +
 doc/guides/howto/index.rst                         |    1 +
 doc/guides/howto/telemetry.rst                     |   86 +
 drivers/Makefile                                   |    3 +
 drivers/meson.build                                |    3 +-
 drivers/telemetry/Makefile                         |    8 +
 drivers/telemetry/meson.build                      |    6 +
 drivers/telemetry/telemetry/Makefile               |   26 +
 drivers/telemetry/telemetry/meson.build            |    5 +
 .../telemetry/rte_pmd_telemetry_version.map        |    9 +
 drivers/telemetry/telemetry/telemetry_driver.c     |   83 +
 lib/Makefile                                       |    2 +
 lib/librte_telemetry/Makefile                      |   28 +
 ...emetry-add-plugin-for-DPDK-metrics-via-DP.patch |  578 +++++++
 lib/librte_telemetry/meson.build                   |    9 +
 lib/librte_telemetry/rte_telemetry.c               | 1737 ++++++++++++++++++++
 lib/librte_telemetry/rte_telemetry.h               |   58 +
 lib/librte_telemetry/rte_telemetry_internal.h      |   72 +
 lib/librte_telemetry/rte_telemetry_parser.c        |  604 +++++++
 lib/librte_telemetry/rte_telemetry_parser.h        |   13 +
 lib/librte_telemetry/rte_telemetry_parser_test.c   |  574 +++++++
 lib/librte_telemetry/rte_telemetry_parser_test.h   |   39 +
 lib/librte_telemetry/rte_telemetry_socket_tests.h  |   36 +
 lib/librte_telemetry/rte_telemetry_version.map     |    7 +
 lib/meson.build                                    |    2 +-
 mk/rte.app.mk                                      |    2 +
 usertools/telemetry_client.py                      |  116 ++
 27 files changed, 4110 insertions(+), 2 deletions(-)
 create mode 100644 doc/guides/howto/telemetry.rst
 create mode 100644 drivers/telemetry/Makefile
 create mode 100644 drivers/telemetry/meson.build
 create mode 100644 drivers/telemetry/telemetry/Makefile
 create mode 100644 drivers/telemetry/telemetry/meson.build
 create mode 100644 drivers/telemetry/telemetry/rte_pmd_telemetry_version.map
 create mode 100644 drivers/telemetry/telemetry/telemetry_driver.c
 create mode 100644 lib/librte_telemetry/Makefile
 create mode 100644 lib/librte_telemetry/collectd_plugin/v1-0001-dpdk_telemetry-add-plugin-for-DPDK-metrics-via-DP.patch
 create mode 100644 lib/librte_telemetry/meson.build
 create mode 100644 lib/librte_telemetry/rte_telemetry.c
 create mode 100644 lib/librte_telemetry/rte_telemetry.h
 create mode 100644 lib/librte_telemetry/rte_telemetry_internal.h
 create mode 100644 lib/librte_telemetry/rte_telemetry_parser.c
 create mode 100644 lib/librte_telemetry/rte_telemetry_parser.h
 create mode 100644 lib/librte_telemetry/rte_telemetry_parser_test.c
 create mode 100644 lib/librte_telemetry/rte_telemetry_parser_test.h
 create mode 100644 lib/librte_telemetry/rte_telemetry_socket_tests.h
 create mode 100644 lib/librte_telemetry/rte_telemetry_version.map
 create mode 100644 usertools/telemetry_client.py