usertools: add new telemetry script

This patch adds a python script that can be used with the new telemetry
socket. It connects as a client to the socket, and allows the user send
a command and see the JSON response.

The example usage below shows the script connecting to the new telemetry
socket, and sending three default telemetry commands entered by the user.
The response for each command is shown below the user input.

Connecting to /var/run/dpdk/rte/dpdk_telemetry.v2
{"version": "DPDK 20.05.0-rc0", "pid": 32794, "max_output_len": 16384}
--> /
{"/": ["/", "/help", "/info"]}
--> /info
{"/info": {"version": "DPDK 20.05.0-rc0", "pid": 32794, \
    "max_output_len": 16384}}
--> /help,/info
{"/help": {"/info": "Returns DPDK Telemetry information. \
    Takes no parameters"}}

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Signed-off-by: Ciara Power <ciara.power@intel.com>
Reviewed-by: Keith Wiles <keith.wiles@intel.com>

MAINTAINERS

@@ -1463,7 +1463,7 @@ Telemetry - EXPERIMENTAL
 M: Kevin Laatz <kevin.laatz@intel.com>
 F: lib/librte_telemetry/
 F: app/test/test_telemetry*
-F: usertools/dpdk-telemetry-client.py
+F: usertools/dpdk-telemetry*
 F: doc/guides/howto/telemetry.rst
 
 BPF - EXPERIMENTAL

usertools/dpdk-telemetry.py

@@ -0,0 +1,83 @@
+#! /usr/bin/python3
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright(c) 2020 Intel Corporation
+
+"""
+Script to be used with V2 Telemetry.
+Allows the user input commands and read the Telemetry response.
+"""
+
+import socket
+import os
+import glob
+import json
+import readline
+
+# global vars
+TELEMETRY_VERSION = "v2"
+CMDS = []
+
+
+def read_socket(sock, buf_len, echo=True):
+    """ Read data from socket and return it in JSON format """
+    reply = sock.recv(buf_len).decode()
+    try:
+        ret = json.loads(reply)
+    except json.JSONDecodeError:
+        print("Error in reply: ", reply)
+        sock.close()
+        raise
+    if echo:
+        print(json.dumps(ret))
+    return ret
+
+
+def handle_socket(path):
+    """ Connect to socket and handle user input """
+    sock = socket.socket(socket.AF_UNIX, socket.SOCK_SEQPACKET)
+    global CMDS
+    print("Connecting to " + path)
+    try:
+        sock.connect(path)
+    except OSError:
+        print("Error connecting to " + path)
+        sock.close()
+        return
+    json_reply = read_socket(sock, 1024)
+    output_buf_len = json_reply["max_output_len"]
+
+    # get list of commands for readline completion
+    sock.send("/".encode())
+    CMDS = read_socket(sock, output_buf_len, False)["/"]
+
+    # interactive prompt
+    text = input('--> ').strip()
+    while text != "quit":
+        if text.startswith('/'):
+            sock.send(text.encode())
+            read_socket(sock, output_buf_len)
+        text = input('--> ').strip()
+    sock.close()
+
+
+def readline_complete(text, state):
+    """ Find any matching commands from the list based on user input """
+    all_cmds = ['quit'] + CMDS
+    if text:
+        matches = [c for c in all_cmds if c.startswith(text)]
+    else:
+        matches = all_cmds
+    return matches[state]
+
+
+readline.parse_and_bind('tab: complete')
+readline.set_completer(readline_complete)
+readline.set_completer_delims(readline.get_completer_delims().replace('/', ''))
+
+# Path to sockets for processes run as a root user
+for f in glob.glob('/var/run/dpdk/*/dpdk_telemetry.%s' % TELEMETRY_VERSION):
+    handle_socket(f)
+# Path to sockets for processes run as a regular user
+for f in glob.glob('/run/user/%d/dpdk/*/dpdk_telemetry.%s' %
+                   (os.getuid(), TELEMETRY_VERSION)):
+    handle_socket(f)

usertools/meson.build

@@ -1,4 +1,4 @@
 # SPDX-License-Identifier: BSD-3-Clause
 # Copyright(c) 2017 Intel Corporation
 
-install_data(['dpdk-devbind.py', 'dpdk-pmdinfo.py'], install_dir: 'bin')
+install_data(['dpdk-devbind.py', 'dpdk-pmdinfo.py', 'dpdk-telemetry.py'], install_dir: 'bin')