add iostat streaming parser

jc/cli.py

@@ -77,6 +77,7 @@ parsers = [
     'ifconfig',
     'ini',
     'iostat',
+    'iostat-s',
     'iptables',
     'iw-scan',
     'jobs',

jc/parsers/iostat_s.py

@@ -0,0 +1,165 @@
+"""jc - JSON CLI output utility `iostat` command output streaming parser
+
+> This streaming parser outputs JSON Lines
+
+<<Short iostat description and caveats>>
+
+Usage (cli):
+
+    $ iostat | jc --iostat-s
+
+Usage (module):
+
+    import jc.parsers.iostat_s
+    result = jc.parsers.iostat_s.parse(iostat_command_output.splitlines())    # result is an iterable object
+    for item in result:
+        # do something
+
+Schema:
+
+    {
+      "iostat":            string,
+      "_jc_meta":                    # This object only exists if using -qq or ignore_exceptions=True
+        {
+          "success":    booean,      # true if successfully parsed, false if error
+          "error":      string,      # exists if "success" is false
+          "line":       string       # exists if "success" is false
+        }
+    }
+
+Examples:
+
+    $ iostat | jc --iostat-s
+    {example output}
+    ...
+
+    $ iostat | jc --iostat-s -r
+    {example output}
+    ...
+"""
+import jc.utils
+from jc.utils import stream_success, stream_error
+from jc.exceptions import ParseError
+import jc.parsers.universal
+
+
+class info():
+    """Provides parser metadata (version, author, etc.)"""
+    version = '1.0'
+    description = '`iostat` command streaming parser'
+    author = 'Kelly Brazil'
+    author_email = 'kellyjonbrazil@gmail.com'
+    compatible = ['linux']
+    streaming = True
+
+
+__version__ = info.version
+
+
+def _process(proc_data):
+    """
+    Final processing to conform to the schema.
+
+    Parameters:
+
+        proc_data:   (Dictionary) raw structured data to process
+
+    Returns:
+
+        Dictionary. Structured data to conform to the schema.
+    """
+    float_list = [
+        'percent_user', 'percent_nice', 'percent_system', 'percent_iowait',
+        'percent_steal', 'percent_idle', 'tps', 'kb_read_s', 'mb_read_s', 'kb_wrtn_s',
+        'mb_wrtn_s', 'rrqm_s', 'wrqm_s', 'r_s', 'w_s', 'rmb_s', 'rkb_s', 'wmb_s',
+        'wkb_s', 'avgrq_sz', 'avgqu_sz', 'await', 'r_await', 'w_await', 'svctm',
+        'percent_util', 'percent_rrqm', 'percent_wrqm', 'aqu_sz', 'rareq_sz', 'wareq_sz'
+    ]
+    int_list = ['kb_read', 'mb_read', 'kb_wrtn', 'mb_wrtn']
+    for key in proc_data:
+        if key in int_list:
+            proc_data[key] = jc.utils.convert_to_int(proc_data[key])
+
+        if key in float_list:
+            proc_data[key] = jc.utils.convert_to_float(proc_data[key])
+
+    return proc_data
+
+def _normalize_headers(line):
+    return line.replace('%', 'percent_').replace('/', '_').replace('-', '_').lower()
+
+def _create_obj_list(section_list, section_name):
+    output_list = jc.parsers.universal.simple_table_parse(section_list)
+    for item in output_list:
+        item['type'] = section_name
+    return output_list
+
+def parse(data, raw=False, quiet=False, ignore_exceptions=False):
+    """
+    Main text parsing generator function. Returns an iterator object.
+
+    Parameters:
+
+        data:              (iterable)  line-based text data to parse (e.g. sys.stdin or str.splitlines())
+        raw:               (boolean)   output preprocessed JSON if True
+        quiet:             (boolean)   suppress warning messages if True
+        ignore_exceptions: (boolean)   ignore parsing exceptions if True
+
+    Yields:
+
+        Dictionary. Raw or processed structured data.
+
+    Returns:
+
+        Iterator object
+    """
+    jc.utils.compatibility(__name__, info.compatible, quiet)
+    jc.utils.streaming_input_type_check(data)
+
+    section = ''  # either 'cpu' or 'device'
+    headers = ''
+    cpu_list = []
+    device_list = []
+
+    for line in data:
+        output_line = {}
+        try:
+            jc.utils.streaming_line_input_type_check(line)
+
+            # ignore blank lines and header line
+            if line == '\n' or line.startswith('Linux'):
+                continue
+
+            if line.startswith('avg-cpu:'):
+                section = 'cpu'
+                headers = _normalize_headers(line)
+                headers = headers.strip().split(':', maxsplit=1)[1:]
+                headers = ' '.join(headers)
+                continue
+
+            if line.startswith('Device'):
+                section = 'device'
+                headers = _normalize_headers(line)
+                headers = headers.replace(':', ' ')
+                continue
+
+            if section == 'cpu':
+                cpu_list.append(headers)
+                cpu_list.append(line)
+                output_line = _create_obj_list(cpu_list, 'cpu')[0]
+                cpu_list = []
+
+
+            if section == 'device':
+                device_list.append(headers)
+                device_list.append(line)
+                output_line = _create_obj_list(device_list, 'device')[0]
+                device_list = []
+
+            if output_line:
+                yield stream_success(output_line, ignore_exceptions) if raw else stream_success(_process(output_line), ignore_exceptions)
+            else:
+                raise ParseError('Not iostat data')
+
+        except Exception as e:
+            yield stream_error(e, ignore_exceptions, line)