add yum_add_repo configuration module

Add in a configuration module that can write out the yum.repo format for
those that want to hook into different repos for installing.

ChangeLog

@@ -22,6 +22,7 @@
  - add yaml/cloud config examples checking tool [revno 706]
  - Fix the merging of group configuration when that group configuration is a
    dict => members. [revno 707]
+ - add yum_add_repo configuration module for adding additional yum repos
 0.7.0:
  - add a 'exception_cb' argument to 'wait_for_url'.  If provided, this
    method will be called back with the exception received and the message.

cloudinit/config/cc_yum_add_repo.py

@@ -0,0 +1,106 @@
+# vi: ts=4 expandtab
+#
+#    Copyright (C) 2012 Yahoo! Inc.
+#
+#    Author: Joshua Harlow <harlowja@yahoo-inc.com>
+#
+#    This program is free software: you can redistribute it and/or modify
+#    it under the terms of the GNU General Public License version 3, as
+#    published by the Free Software Foundation.
+#
+#    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/>.
+
+import os
+
+from cloudinit import util
+
+import configobj
+
+
+def _canonicalize_id(repo_id):
+    repo_id = repo_id.lower().replace("-", "_")
+    repo_id = repo_id.replace(" ", "_")
+    return repo_id
+
+
+def _format_repo_value(val):
+    if isinstance(val, (bool)):
+        # Seems like yum prefers 1/0
+        return str(int(val))
+    if isinstance(val, (list, tuple)):
+        # Can handle 'lists' in certain cases
+        # See: http://bit.ly/Qqrf1t
+        return "\n    ".join([_format_repo_value(v) for v in val])
+    if not isinstance(val, (basestring, str)):
+        return str(val)
+    return val
+
+
+## TODO(harlowja): move to distro?
+# See man yum.conf
+def _format_repository_config(repo_id, repo_config):
+    to_be = configobj.ConfigObj()
+    to_be[repo_id] = {}
+    # Do basic translation of the items -> values
+    for (k, v) in repo_config.items():
+        # For now assume that people using this know
+        # the format of yum and don't verify keys/values further
+        to_be[repo_id][k] = _format_repo_value(v)
+    lines = to_be.write()
+    lines.insert(0, "# Created by cloud-init on %s" % (util.time_rfc2822()))
+    return "\n".join(lines)
+
+
+def handle(name, cfg, _cloud, log, _args):
+    repos = cfg.get('yum_repos')
+    if not repos:
+        log.debug(("Skipping module named %s,"
+                   " no 'yum_repos' configuration found"), name)
+        return
+    repo_base_path = util.get_cfg_option_str(cfg, 'yum_repo_dir',
+                                             '/etc/yum.repos.d/')
+    repo_locations = {}
+    repo_configs = {}
+    for (repo_id, repo_config) in repos.items():
+        canon_repo_id = _canonicalize_id(repo_id)
+        repo_fn_pth = os.path.join(repo_base_path, "%s.repo" % (canon_repo_id))
+        if os.path.exists(repo_fn_pth):
+            log.info("Skipping repo %s, file %s already exists!",
+                     repo_id, repo_fn_pth)
+            continue
+        elif canon_repo_id in repo_locations:
+            log.info("Skipping repo %s, file %s already pending!",
+                     repo_id, repo_fn_pth)
+            continue
+        if not repo_config:
+            repo_config = {}
+        # Do some basic sanity checks/cleaning
+        n_repo_config = {}
+        for (k, v) in repo_config.items():
+            k = k.lower().strip().replace("-", "_")
+            if k:
+                n_repo_config[k] = v
+        repo_config = n_repo_config
+        missing_required = 0
+        for req_field in ['baseurl']:
+            if not req_field in repo_config:
+                log.warn(("Repository %s does not contain a %s"
+                           " configuration 'required' entry"),
+                         repo_id, req_field)
+                missing_required += 1
+        if not missing_required:
+            repo_configs[canon_repo_id] = repo_config
+            repo_locations[canon_repo_id] = repo_fn_pth
+        else:
+            log.warn("Repository %s is missing %s required fields, skipping!",
+                     repo_id, missing_required)
+    for (c_repo_id, path) in repo_locations.items():
+        repo_blob = _format_repository_config(c_repo_id,
+                                              repo_configs.get(c_repo_id))
+        util.write_file(path, repo_blob)

doc/examples/cloud-config-yum-repo.txt

@@ -0,0 +1,20 @@
+#cloud-config
+# vim: syntax=yaml
+#
+# Add yum repository configuration to the system
+#
+# The following example adds the file /etc/yum.repos.d/epel_testing.repo
+# which can then subsequently be used by yum for later operations.
+yum_repos:
+    # The name of the repository
+    epel-testing:
+        # Any repository configuration options
+        # See: man yum.conf
+        #
+        # This one is required!
+        baseurl: http://download.fedoraproject.org/pub/epel/testing/5/$basearch
+        enabled: false
+        failovermethod: priority
+        gpgcheck: true
+        gpgkey: file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL
+        name: Extra Packages for Enterprise Linux 5 - Testing

tests/unittests/test_handler/test_handler_yum_add_repo.py

@@ -0,0 +1,68 @@
+from cloudinit import helpers
+from cloudinit import util
+
+from cloudinit.config import cc_yum_add_repo
+
+from tests.unittests import helpers
+
+import logging
+
+from StringIO import StringIO
+
+import configobj
+
+LOG = logging.getLogger(__name__)
+
+
+class TestConfig(helpers.FilesystemMockingTestCase):
+    def setUp(self):
+        super(TestConfig, self).setUp()
+        self.tmp = self.makeDir(prefix="unittest_")
+
+    def test_bad_config(self):
+        cfg = {
+            'yum_repos': {
+                'epel-testing': {
+                    'name': 'Extra Packages for Enterprise Linux 5 - Testing',
+                    # Missing this should cause the repo not to be written
+                    #'baseurl': 'http://blah.org/pub/epel/testing/5/$basearch',
+                    'enabled': False,
+                    'gpgcheck': True,
+                    'gpgkey': 'file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL',
+                    'failovermethod': 'priority',
+                },
+            },
+        }
+        self.patchUtils(self.tmp)
+        cc_yum_add_repo.handle('yum_add_repo', cfg, None, LOG, [])
+        with self.assertRaises(IOError):
+            util.load_file("/etc/yum.repos.d/epel_testing.repo")
+
+    def test_write_config(self):
+        cfg = {
+            'yum_repos': {
+                'epel-testing': {
+                    'name': 'Extra Packages for Enterprise Linux 5 - Testing',
+                    'baseurl': 'http://blah.org/pub/epel/testing/5/$basearch',
+                    'enabled': False,
+                    'gpgcheck': True,
+                    'gpgkey': 'file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL',
+                    'failovermethod': 'priority',
+                },
+            },
+        }
+        self.patchUtils(self.tmp)
+        cc_yum_add_repo.handle('yum_add_repo', cfg, None, LOG, [])
+        contents = util.load_file("/etc/yum.repos.d/epel_testing.repo")
+        contents = configobj.ConfigObj(StringIO(contents))
+        expected = {
+            'epel_testing': {
+                'name': 'Extra Packages for Enterprise Linux 5 - Testing',
+                'failovermethod': 'priority',
+                'gpgkey': 'file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL',
+                'enabled': '0',
+                'baseurl': 'http://blah.org/pub/epel/testing/5/$basearch',
+                'gpgcheck': '1',
+            }
+        }
+        self.assertEquals(expected, dict(contents))