Add API version and have server reject incompatible clients.

This patch contains 2 parts.

The first part is a small utility to create and validate the current
API. To do this it needs to load ipalib which on a fresh system
introduces a few problems, namely that it relies on a python plugin
to set the default encoding to utf8. For our purposes we can skip that.
It is also important that any optional plugins be loadable so the
API can be examined.

The second part is a version exchange between the client and server.
The version has a major and a minor version. The major verion is
updated whenever existing API changes. The minor version is updated when
new API is added. A request will be rejected if either the major versions
don't match or if the client major version is higher than then server
major version (though by implication new API would return a command not
found if allowed to proceed).

To determine the API version of the server from a client use the ping
command.

ticket 584

1 files changed, 238 insertions, 0 deletions

diff --git a/makeapi b/makeapi
new file mode 100755
index 000000000..30eac18c3
--- /dev/null
+++ b/makeapi
@@ -0,0 +1,238 @@
+#!/usr/bin/env python
+# Authors:
+#   Rob Crittenden <rcritten@redhat.com>
+#
+# Copyright (C) 2011  Red Hat
+# see file 'COPYING' for use and warranty information
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# Test the API against a known-good API to ensure that changes aren't made
+# lightly.
+
+import sys
+import os
+import re
+from ipalib import *
+from ipalib.text import Gettext
+
+API_FILE='API.txt'
+
+API_FILE_DIFFERENCE = 1
+API_NEW_COMMAND = 2
+API_NO_FILE = 4
+
+def parse_options():
+    from optparse import OptionParser
+
+    parser = OptionParser()
+    parser.add_option("--validate", dest="validate", action="store_true",
+        default=False, help="Validate the API vs the stored API")
+
+    options, args = parser.parse_args()
+    return options, args
+
+def strip_doc(line):
+    """
+    Remove the doc= line from the repr() of a Paramter.
+    """
+    s = line.find(' doc=')
+    if s >= 0:
+        e = line.find('), ', s)
+        line = '%s%s' % (line[0:s], line[e+2:])
+
+    return line
+
+def make_api():
+    """
+    Write a new API file from the current tree.
+    """
+    fd = open(API_FILE, 'w')
+    for cmd in api.Command():
+        fd.write('command: %s\n' % cmd.name)
+        fd.write('args: %d,%d,%d\n' % (len(cmd.args), len(cmd.options), len(cmd.output)))
+        for a in cmd.args():
+            fd.write('arg: %s\n' % strip_doc(repr(a)))
+        for o in cmd.options():
+            fd.write('option: %s\n' % strip_doc(repr(o)))
+        for o in cmd.output():
+            fd.write('output: %s\n' % strip_doc(repr(o)))
+    fd.close()
+
+    return 0
+
+def find_name(line):
+    """
+    Break apart a Param line and pull out the name. It would be nice if we
+    could just eval() the line but we wouldn't have defined any validators
+    or normalizers it may be using.
+    """
+    m = re.match('^[a-zA-Z0-9]+\(\'([a-z][_a-z0-9?\*\+]*)\'.*', line)
+    if m:
+        name = m.group(1)
+    else:
+        print "Couldn't find name in: %s" % line
+        name = ''
+    return name
+
+def validate_api():
+    """
+    Compare the API in the file to the one in ipalib.
+
+    Return a bitwise return code to identify the types of errors found, if
+    any.
+    """
+    fd = open(API_FILE, 'r')
+    lines = fd.readlines()
+    fd.close()
+
+    rval = 0
+
+    # First run through the file and compare it to the API
+    existing_cmds = []
+    cmd = None
+    for line in lines:
+        line = line.strip()
+        if line.startswith('command:'):
+            if cmd:
+                # Check the args of the previous command.
+                if found_args != expected_args:
+                    print 'Argument count in %s of %d doesn\'t match expected: %d' % (
+                        name, found_args, expected_args)
+                    rval |= API_FILE_DIFFERENCE
+                if found_options != expected_options:
+                    print 'Options count in %s of %d doesn\'t match expected: %d' % (
+                        name, found_options, expected_options)
+                    rval |= API_FILE_DIFFERENCE
+                if found_output != expected_output:
+                    print 'Output count in %s of %d doesn\'t match expected: %d' % (
+                        name, found_output, expected_output)
+                    rval |= API_FILE_DIFFERENCE
+            (arg, name) = line.split(': ', 1)
+            if name not in api.Command:
+                print "Command %s in API file, not in ipalib" % name
+                rval |= API_FILE_DIFFERENCE
+                cmd = None
+            else:
+                existing_cmds.append(name)
+                cmd = api.Command[name]
+            found_args = 0
+            found_options = 0
+            found_output = 0
+        if line.startswith('args:') and cmd:
+            line = line.replace('args: ', '')
+            (expected_args, expected_options, expected_output) = line.split(',')
+            expected_args = int(expected_args)
+            expected_options = int(expected_options)
+            expected_output = int(expected_output)
+        if line.startswith('arg:') and cmd:
+            line = line.replace('arg: ', '')
+            found = False
+            for a in cmd.args():
+                if strip_doc(repr(a)) == line:
+                    found = True
+                else:
+                    arg = find_name(line)
+                    if a.name == arg:
+                        found = True
+                        print 'Arg in %s doesn\'t match.\nGot      %s\nExpected %s' % (
+                            name, strip_doc(repr(a)), line)
+                        rval |= API_FILE_DIFFERENCE
+            if found:
+                found_args += 1
+            else:
+                arg = find_name(line)
+                print "Argument '%s' in command '%s' in API file not found" % (arg, name)
+                rval |= API_FILE_DIFFERENCE
+        if line.startswith('option:') and cmd:
+            line = line.replace('option: ', '')
+            found = False
+            for o in cmd.options():
+                if strip_doc(repr(o)) == line:
+                    found = True
+                else:
+                    option = find_name(line)
+                    if o.name == option:
+                        found = True
+                        print 'Option in %s doesn\'t match. Got %s Expected %s' % (name, o, line)
+                        rval |= API_FILE_DIFFERENCE
+            if found:
+                found_options += 1
+            else:
+                option = find_name(line)
+                print "Option '%s' in command '%s' in API file not found" % (option, name)
+                rval |= API_FILE_DIFFERENCE
+        if line.startswith('output:') and cmd:
+            line = line.replace('output: ', '')
+            found = False
+            for o in cmd.output():
+                if strip_doc(repr(o)) == line:
+                    found = True
+                else:
+                    output = find_name(line)
+                    if o.name == output:
+                        found = True
+                        print 'Output in %s doesn\'t match. Got %s Expected %s' % (name, o, line)
+                        rval |= API_FILE_DIFFERENCE
+            if found:
+                found_output += 1
+            else:
+                output = find_name(line)
+                print "Option '%s' in command '%s' in API file not found" % (output, name)
+                rval |= API_FILE_DIFFERENCE
+
+    # Now look for new commands not in the current API
+    for cmd in api.Command():
+        if cmd.name not in existing_cmds:
+            print "Command %s in ipalib, not in API" % cmd.name
+            rval |= API_NEW_COMMAND
+
+    return rval
+
+def main():
+    options, args = parse_options()
+
+    cfg = dict(
+        context='cli',
+        in_server=False,
+        debug=False,
+        verbose=0,
+        validate_api=True,
+        enable_ra=True,
+    )
+
+    api.bootstrap(**cfg)
+    api.finalize()
+
+    if options.validate:
+        if not os.path.exists(API_FILE):
+            print 'No %s to validate' % API_FILE
+            rval = API_NO_FILE
+        else:
+            rval = validate_api()
+    else:
+        print "Writing API to API.txt"
+        rval = make_api()
+
+    if rval & API_FILE_DIFFERENCE:
+        print ''
+        print 'There are one or more changes to the API.\nEither undo the API changes or update API.txt and increment the major version in VERSION.'
+
+    if rval & API_NEW_COMMAND:
+        print ''
+        print 'There are one or more new commands defined.\nUpdate API.txt and increment the minor version in VERSION.'
+
+    return rval
+
+sys.exit(main())