[patch lnst 3/3] cmd: allow to parse JSON stdout into dictionary

[Jiri Pirko]

From: Jiri Pirko <jiri(a)mellanox.com&gt;

This is handy for processing output of commands producing JSON.

Signed-off-by: Jiri Pirko <jiri(a)mellanox.com&gt;
---
 lnst/Common/ExecCmd.py        | 6 +++++-
 lnst/Common/NetTestCommand.py | 3 ++-
 lnst/Controller/Task.py       | 4 ++++
 3 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/lnst/Common/ExecCmd.py b/lnst/Common/ExecCmd.py
index d432c2c..24715ae 100644
--- a/lnst/Common/ExecCmd.py
+++ b/lnst/Common/ExecCmd.py
@@ -51,7 +51,7 @@ def log_output(log_func, out_type, out):
              "----------------------------"
              % (out_type, out))
 
-def exec_cmd(cmd, die_on_err=True, log_outputs=True, report_stderr=False):
+def exec_cmd(cmd, die_on_err=True, log_outputs=True, report_stderr=False, json=False):
     cmd = cmd.rstrip(" ")
     logging.debug("Executing: \"%s\"" % cmd)
     subp = subprocess.Popen(cmd, shell=True, stdout=subprocess.PIPE,
@@ -72,4 +72,8 @@ def exec_cmd(cmd, die_on_err=True, log_outputs=True,
report_stderr=False):
         logging.error(err)
         raise err
 
+    if json:
+        import json
+        data_stdout = json.loads(data_stdout)
+
     return data_stdout, data_stderr
diff --git a/lnst/Common/NetTestCommand.py b/lnst/Common/NetTestCommand.py
index 3c290dc..52f2a73 100644
--- a/lnst/Common/NetTestCommand.py
+++ b/lnst/Common/NetTestCommand.py
@@ -407,7 +407,8 @@ class NetTestCommandExec(NetTestCommandGeneric):
                 stdout, stderr = self.exec_from(self._command["from"],
                                                 self._command["command"])
             else:
-                stdout, stderr = self.exec_cmd(self._command["command"])
+                json = True if "json" in self._command else False
+                stdout, stderr = self.exec_cmd(self._command["command"],
json=json)
             res_data = {"stdout": stdout, "stderr": stderr}
             self.set_pass(res_data)
         except ExecCmdFail as e:
diff --git a/lnst/Controller/Task.py b/lnst/Controller/Task.py
index 1226ce2..80e4b75 100644
--- a/lnst/Controller/Task.py
+++ b/lnst/Controller/Task.py
@@ -242,6 +242,8 @@ class HostAPI(object):
             :type timeout: int
             :param tool: Run from a tool (the same as 'from' in XML).
             :type tool: string
+            :param json: Process JSON output into dictionary.
+            :type json: bool
 
             :return: A handle for process.
             :rtype: ProcessAPI
@@ -283,6 +285,8 @@ class HostAPI(object):
                 cmd["netns"] = argval
             elif arg == "save_output":
                 pass # now ignored as output is saved always
+            elif arg == "json":
+                cmd["json"] = argval
             else:
                 msg = "Argument '%s' not recognised by the run()
method." % arg
                 raise TaskError(msg)
-- 
2.5.5