inventory: write sensor yaml parser

Write python-based parser for sensor.yaml. The parser generates
sensor-gen.cpp,which is having a map of sensorid(key) and
sensorinfo(value).

Change-Id: I5aa2d2bc871ced06e5e4c164a67eeb5974031d5d
Signed-off-by: Ratan Gupta <ratagupt@in.ibm.com>
diff --git a/scripts/sensor_gen.py b/scripts/sensor_gen.py
new file mode 100755
index 0000000..822a00a
--- /dev/null
+++ b/scripts/sensor_gen.py
@@ -0,0 +1,60 @@
+#!/usr/bin/env python
+
+import os
+import sys
+import yaml
+import argparse
+from mako.template import Template
+
+
+def generate_cpp(sensor_yaml, output_dir):
+    with open(os.path.join(script_dir, sensor_yaml), 'r') as f:
+        ifile = yaml.safe_load(f)
+        if not isinstance(ifile, dict):
+            ifile = {}
+
+        # Render the mako template
+
+        t = Template(filename=os.path.join(
+                     script_dir,
+                     "writesensor.mako.cpp"))
+
+        output_cpp = os.path.join(output_dir, "sensor-gen.cpp")
+        with open(output_cpp, 'w') as fd:
+            fd.write(t.render(sensorDict=ifile))
+
+
+def main():
+
+    valid_commands = {
+        'generate-cpp': generate_cpp
+    }
+    parser = argparse.ArgumentParser(
+        description="IPMI Sensor parser and code generator")
+
+    parser.add_argument(
+        '-i', '--sensor_yaml', dest='sensor_yaml',
+        default='example.yaml', help='input sensor yaml file to parse')
+
+    parser.add_argument(
+        "-o", "--output-dir", dest="outputdir",
+        default=".",
+        help="output directory")
+
+    parser.add_argument(
+        'command', metavar='COMMAND', type=str,
+        choices=valid_commands.keys(),
+        help='Command to run.')
+
+    args = parser.parse_args()
+
+    if (not (os.path.isfile(os.path.join(script_dir, args.sensor_yaml)))):
+        sys.exit("Can not find input yaml file " + args.sensor_yaml)
+
+    function = valid_commands[args.command]
+    function(args.sensor_yaml, args.outputdir)
+
+
+if __name__ == '__main__':
+    script_dir = os.path.dirname(os.path.realpath(__file__))
+    main()