Changeset c259a77 for fedd/federation/client_lib.py

Timestamp:

Jun 3, 2014 4:29:31 PM (10 years ago)

Author:

Ted Faber <faber@…>

Branches:

master

Children:

0b217d1

Parents:

ba07149

Message:

Service info in xml files.

File:

• fedd/federation/client_lib.py (modified) (2 diffs)

fedd/federation/client_lib.py

@@ -4 +4 @@
 import pwd
 import os
+import re
 import os.path
+import xml.parsers.expat
 
 from string import join
 from datetime import datetime
-
 
 from deter import fedid
@@ -137 +138 @@
     return rv
 
+ns_service_re = re.compile('^\\s*#\\s*SERVICE:\\s*([\\S]+)')
+xml_service_re = re.compile('SERVICE:\\s*([\\S]+)\\s*$')
+
+def parse_service(svc):
+    """
+    Pasre a service entry into a hash representing a service entry in a
+    message.  The format is:
+        svc_name:exporter(s):importer(s):attr=val,attr=val
+    The svc_name is the service name, exporter is the exporting testbeds
+    (comma-separated) importer is the importing testbeds (if any) and the rest
+    are attr=val pairs that will become attributes of the service.  These
+    include parameters and other such stuff.
+    """
+
+    terms = svc.split(':')
+    svcd = { }
+    if len(terms) < 2 or len(terms[0]) == 0 or len(terms[1]) == 0:
+        sys.exit("Bad service description '%s': Not enough terms" % svc)
+
+    svcd['name'] = terms[0]
+    svcd['export'] = terms[1].split(",")
+    if len(terms) > 2 and len(terms[2]) > 0:
+        svcd['import'] = terms[2].split(",")
+    if len(terms) > 3 and len(terms[3]) > 0:
+        svcd['fedAttr'] = [ ]
+        for t in terms[3].split(";"):
+            i = t.find("=")
+            if i != -1 :
+                svcd['fedAttr'].append(
+                        {'attribute': t[0:i], 'value': t[i+1:]})
+            else:
+                sys.exit("Bad service attribute '%s': no equals sign" % t)
+    return svcd
+
+def service_dict_to_line(d):
+    """
+    Convert a dict containing a service description into a colon separated
+    service description suitable for inclusion in a file or command line.
+    """
+
+    return 'SERVICE: %s' % (
+            ':'.join([
+                d.get('name', ''),
+                ','.join(d.get('export','')),
+                ','.join(d.get('import','')),
+                ','.join([
+                    '='.join((dd.get('attribute', ''), dd.get('value',''))) \
+                        for dd in d.get('fedAttr', [])
+                ])
+            ]))
+
+def extract_services_from_xml(string=None, file=None, filename=None):
+    class parser:
+        def __init__(self):
+            self.svcs = []
+        def comment_handler(self, data):
+            for l in data.split('\n'):
+                if xml_service_re.match(l):
+                    self.svcs.append(
+                            parse_service(xml_service_re.match(l).group(1)))
+
+    p = parser()
+    xp = xml.parsers.expat.ParserCreate()
+
+    xp.CommentHandler = p.comment_handler
+
+    num_set = len([ x for x in (string, filename, file)\
+            if x is not None ])
+
+    if num_set != 1:
+        raise RuntimeError("Exactly one one of file, filename and string " + \
+                "must be set")
+    elif filename:
+        f = open(filename, "r")
+        xp.ParseFile(f)
+        f.close()
+    elif file:
+        xp.ParseFile(file)
+    elif string:
+        xp.Parse(string, True)
+
+    return p.svcs
+
 def wrangle_standard_options(opts):
     """