Add a openstack specific datasource

Openstack has a unique derivative datasource that is gaining usage.
Previously the config drive datasource provided part of this functionality
as well as the ec2 datasource, but since new functionality is being added
to openstack's special datasource it seems beneficial to combine the used
parts into a new datasource just made for handling openstack deployments
that use the openstack metadata service (possibly in combination with the
ec2 metadata service).

This patch factors out the common logic shared between the config drive
and the openstack metadata datasource and places that in a shared helper
file and then creates a new openstack datasource that readers from the
openstack metadata service and refactors the config drive datasource to
use this common logic.

1 files changed, 111 insertions, 357 deletions

diff --git a/cloudinit/sources/DataSourceConfigDrive.py b/cloudinit/sources/DataSourceConfigDrive.py
index 2a244496..142e0eb8 100644
--- a/cloudinit/sources/DataSourceConfigDrive.py
+++ b/cloudinit/sources/DataSourceConfigDrive.py
@@ -18,181 +18,79 @@
 #    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 base64
-import json
 import os
 
 from cloudinit import log as logging
 from cloudinit import sources
 from cloudinit import util
 
+from cloudinit.sources.helpers import openstack
+
 LOG = logging.getLogger(__name__)
 
 # Various defaults/constants...
 DEFAULT_IID = "iid-dsconfigdrive"
 DEFAULT_MODE = 'pass'
-CFG_DRIVE_FILES_V1 = [
-    "etc/network/interfaces",
-    "root/.ssh/authorized_keys",
-    "meta.js",
-]
 DEFAULT_METADATA = {
     "instance-id": DEFAULT_IID,
 }
 VALID_DSMODES = ("local", "net", "pass", "disabled")
+FS_TYPES = ('vfat', 'iso9660')
+LABEL_TYPES = ('config-2',)
+OPTICAL_DEVICES = tuple(('/dev/sr%s' % i for i in range(0, 2)))
 
 
-class ConfigDriveHelper(object):
-    def __init__(self, distro):
-        self.distro = distro
-
-    def on_first_boot(self, data):
-        if not data:
-            data = {}
-        if 'network_config' in data:
-            LOG.debug("Updating network interfaces from config drive")
-            self.distro.apply_network(data['network_config'])
-        files = data.get('files')
-        if files:
-            LOG.debug("Writing %s injected files", len(files))
-            try:
-                write_files(files)
-            except IOError:
-                util.logexc(LOG, "Failed writing files")
-
-
-class DataSourceConfigDrive(sources.DataSource):
+class DataSourceConfigDrive(openstack.SourceMixin, sources.DataSource):
     def __init__(self, sys_cfg, distro, paths):
-        sources.DataSource.__init__(self, sys_cfg, distro, paths)
+        super(DataSourceConfigDrive, self).__init__(sys_cfg, distro, paths)
         self.source = None
         self.dsmode = 'local'
         self.seed_dir = os.path.join(paths.seed_dir, 'config_drive')
         self.version = None
         self.ec2_metadata = None
-        self.helper = ConfigDriveHelper(distro)
+        self.files = {}
 
     def __str__(self):
         root = sources.DataSource.__str__(self)
-        mstr = "%s [%s,ver=%s]" % (root,
-                                   self.dsmode,
-                                   self.version)
+        mstr = "%s [%s,ver=%s]" % (root, self.dsmode, self.version)
         mstr += "[source=%s]" % (self.source)
         return mstr
 
-    def _ec2_name_to_device(self, name):
-        if not self.ec2_metadata:
-            return None
-        bdm = self.ec2_metadata.get('block-device-mapping', {})
-        for (ent_name, device) in bdm.items():
-            if name == ent_name:
-                return device
-        return None
-
-    def _os_name_to_device(self, name):
-        device = None
-        try:
-            criteria = 'LABEL=%s' % (name)
-            if name in ['swap']:
-                criteria = 'TYPE=%s' % (name)
-            dev_entries = util.find_devs_with(criteria)
-            if dev_entries:
-                device = dev_entries[0]
-        except util.ProcessExecutionError:
-            pass
-        return device
-
-    def _validate_device_name(self, device):
-        if not device:
-            return None
-        if not device.startswith("/"):
-            device = "/dev/%s" % device
-        if os.path.exists(device):
-            return device
-        # Durn, try adjusting the mapping
-        remapped = self._remap_device(os.path.basename(device))
-        if remapped:
-            LOG.debug("Remapped device name %s => %s", device, remapped)
-            return remapped
-        return None
-
-    def device_name_to_device(self, name):
-        # Translate a 'name' to a 'physical' device
-        if not name:
-            return None
-        # Try the ec2 mapping first
-        names = [name]
-        if name == 'root':
-            names.insert(0, 'ami')
-        if name == 'ami':
-            names.append('root')
-        device = None
-        LOG.debug("Using ec2 metadata lookup to find device %s", names)
-        for n in names:
-            device = self._ec2_name_to_device(n)
-            device = self._validate_device_name(device)
-            if device:
-                break
-        # Try the openstack way second
-        if not device:
-            LOG.debug("Using os lookup to find device %s", names)
-            for n in names:
-                device = self._os_name_to_device(n)
-                device = self._validate_device_name(device)
-                if device:
-                    break
-        # Ok give up...
-        if not device:
-            return None
-        else:
-            LOG.debug("Using cfg drive lookup mapped to device %s", device)
-            return device
-
     def get_data(self):
         found = None
         md = {}
-
         results = {}
         if os.path.isdir(self.seed_dir):
             try:
-                results = read_config_drive_dir(self.seed_dir)
+                results = read_config_drive(self.seed_dir)
                 found = self.seed_dir
-            except NonConfigDriveDir:
+            except openstack.NonReadable:
                 util.logexc(LOG, "Failed reading config drive from %s",
                             self.seed_dir)
         if not found:
-            devlist = find_candidate_devs()
-            for dev in devlist:
+            for dev in find_candidate_devs():
                 try:
-                    results = util.mount_cb(dev, read_config_drive_dir)
+                    results = util.mount_cb(dev, read_config_drive)
                     found = dev
-                    break
-                except (NonConfigDriveDir, util.MountFailedError):
+                except openstack.NonReadable:
                     pass
-                except BrokenConfigDriveDir:
-                    util.logexc(LOG, "broken config drive: %s", dev)
-
+                except util.MountFailedError:
+                    pass
+                except openstack.BrokenMetadata:
+                    util.logexc(LOG, "Broken config drive: %s", dev)
+                if found:
+                    break
         if not found:
             return False
 
-        md = results['metadata']
+        md = results.get('metadata', {})
         md = util.mergemanydict([md, DEFAULT_METADATA])
-
-        # Perform some metadata 'fixups'
-        #
-        # OpenStack uses the 'hostname' key
-        # while most of cloud-init uses the metadata
-        # 'local-hostname' key instead so if it doesn't
-        # exist we need to make sure its copied over.
-        for (tgt, src) in [('local-hostname', 'hostname')]:
-            if tgt not in md and src in md:
-                md[tgt] = md[src]
-
         user_dsmode = results.get('dsmode', None)
         if user_dsmode not in VALID_DSMODES + (None,):
-            LOG.warn("user specified invalid mode: %s" % user_dsmode)
+            LOG.warn("User specified invalid mode: %s", user_dsmode)
             user_dsmode = None
 
-        dsmode = get_ds_mode(cfgdrv_ver=results['cfgdrive_ver'],
+        dsmode = get_ds_mode(cfgdrv_ver=results['version'],
                              ds_cfg=self.ds_cfg.get('dsmode'),
                              user=user_dsmode)
 
@@ -209,7 +107,7 @@ class DataSourceConfigDrive(sources.DataSource):
         prev_iid = get_previous_iid(self.paths)
         cur_iid = md['instance-id']
         if prev_iid != cur_iid and self.dsmode == "local":
-            self.helper.on_first_boot(results)
+            on_first_boot(results, distro=self.distro)
 
         # dsmode != self.dsmode here if:
         #  * dsmode = "pass",  pass means it should only copy files and then
@@ -225,16 +123,11 @@ class DataSourceConfigDrive(sources.DataSource):
         self.metadata = md
         self.ec2_metadata = results.get('ec2-metadata')
         self.userdata_raw = results.get('userdata')
-        self.version = results['cfgdrive_ver']
-
+        self.version = results['version']
+        self.files.update(results.get('files', {}))
+        self.vendordata_raw = results.get('vendordata')
         return True
 
-    def get_public_ssh_keys(self):
-        name = "public_keys"
-        if self.version == 1:
-            name = "public-keys"
-        return sources.normalize_pubkey_data(self.metadata.get(name))
-
 
 class DataSourceConfigDriveNet(DataSourceConfigDrive):
     def __init__(self, sys_cfg, distro, paths):
@@ -242,222 +135,6 @@ class DataSourceConfigDriveNet(DataSourceConfigDrive):
         self.dsmode = 'net'
 
 
-class NonConfigDriveDir(Exception):
-    pass
-
-
-class BrokenConfigDriveDir(Exception):
-    pass
-
-
-def find_candidate_devs():
-    """Return a list of devices that may contain the config drive.
-
-    The returned list is sorted by search order where the first item has
-    should be searched first (highest priority)
-
-    config drive v1:
-       Per documentation, this is "associated as the last available disk on the
-       instance", and should be VFAT.
-       Currently, we do not restrict search list to "last available disk"
-
-    config drive v2:
-       Disk should be:
-        * either vfat or iso9660 formated
-        * labeled with 'config-2'
-    """
-
-    # Query optical drive to get it in blkid cache for 2.6 kernels
-    util.find_devs_with(path="/dev/sr0")
-    util.find_devs_with(path="/dev/sr1")
-
-    by_fstype = (util.find_devs_with("TYPE=vfat") +
-                 util.find_devs_with("TYPE=iso9660"))
-    by_label = util.find_devs_with("LABEL=config-2")
-
-    # give preference to "last available disk" (vdb over vda)
-    # note, this is not a perfect rendition of that.
-    by_fstype.sort(reverse=True)
-    by_label.sort(reverse=True)
-
-    # combine list of items by putting by-label items first
-    # followed by fstype items, but with dupes removed
-    combined = (by_label + [d for d in by_fstype if d not in by_label])
-
-    # We are looking for a block device or partition with necessary label or
-    # an unpartitioned block device.
-    combined = [d for d in combined
-                    if d in by_label or not util.is_partition(d)]
-
-    return combined
-
-
-def read_config_drive_dir(source_dir):
-    last_e = NonConfigDriveDir("Not found")
-    for finder in (read_config_drive_dir_v2, read_config_drive_dir_v1):
-        try:
-            data = finder(source_dir)
-            return data
-        except NonConfigDriveDir as exc:
-            last_e = exc
-    raise last_e
-
-
-def read_config_drive_dir_v2(source_dir, version="2012-08-10"):
-
-    if (not os.path.isdir(os.path.join(source_dir, "openstack", version)) and
-        os.path.isdir(os.path.join(source_dir, "openstack", "latest"))):
-        LOG.warn("version '%s' not available, attempting to use 'latest'" %
-                 version)
-        version = "latest"
-
-    datafiles = (
-        ('metadata',
-         "openstack/%s/meta_data.json" % version, True, json.loads),
-        ('userdata', "openstack/%s/user_data" % version, False, None),
-        ('ec2-metadata', "ec2/latest/meta-data.json", False, json.loads),
-    )
-
-    results = {'userdata': None}
-    for (name, path, required, process) in datafiles:
-        fpath = os.path.join(source_dir, path)
-        data = None
-        found = False
-        if os.path.isfile(fpath):
-            try:
-                data = util.load_file(fpath)
-            except IOError:
-                raise BrokenConfigDriveDir("Failed to read: %s" % fpath)
-            found = True
-        elif required:
-            raise NonConfigDriveDir("Missing mandatory path: %s" % fpath)
-
-        if found and process:
-            try:
-                data = process(data)
-            except Exception as exc:
-                raise BrokenConfigDriveDir(("Failed to process "
-                                            "path: %s") % fpath)
-
-        if found:
-            results[name] = data
-
-    # instance-id is 'uuid' for openstack. just copy it to instance-id.
-    if 'instance-id' not in results['metadata']:
-        try:
-            results['metadata']['instance-id'] = results['metadata']['uuid']
-        except KeyError:
-            raise BrokenConfigDriveDir("No uuid entry in metadata")
-
-    if 'random_seed' in results['metadata']:
-        random_seed = results['metadata']['random_seed']
-        try:
-            results['metadata']['random_seed'] = base64.b64decode(random_seed)
-        except (ValueError, TypeError) as exc:
-            raise BrokenConfigDriveDir("Badly formatted random_seed: %s" % exc)
-
-    def read_content_path(item):
-        # do not use os.path.join here, as content_path starts with /
-        cpath = os.path.sep.join((source_dir, "openstack",
-                                  "./%s" % item['content_path']))
-        return util.load_file(cpath)
-
-    files = {}
-    try:
-        for item in results['metadata'].get('files', {}):
-            files[item['path']] = read_content_path(item)
-
-        # the 'network_config' item in metadata is a content pointer
-        # to the network config that should be applied.
-        # in folsom, it is just a '/etc/network/interfaces' file.
-        item = results['metadata'].get("network_config", None)
-        if item:
-            results['network_config'] = read_content_path(item)
-    except Exception as exc:
-        raise BrokenConfigDriveDir("Failed to read file %s: %s" % (item, exc))
-
-    # to openstack, user can specify meta ('nova boot --meta=key=value') and
-    # those will appear under metadata['meta'].
-    # if they specify 'dsmode' they're indicating the mode that they intend
-    # for this datasource to operate in.
-    try:
-        results['dsmode'] = results['metadata']['meta']['dsmode']
-    except KeyError:
-        pass
-
-    results['files'] = files
-    results['cfgdrive_ver'] = 2
-    return results
-
-
-def read_config_drive_dir_v1(source_dir):
-    """
-    read source_dir, and return a tuple with metadata dict, user-data,
-    files and version (1).  If not a valid dir, raise a NonConfigDriveDir
-    """
-
-    found = {}
-    for af in CFG_DRIVE_FILES_V1:
-        fn = os.path.join(source_dir, af)
-        if os.path.isfile(fn):
-            found[af] = fn
-
-    if len(found) == 0:
-        raise NonConfigDriveDir("%s: %s" % (source_dir, "no files found"))
-
-    md = {}
-    keydata = ""
-    if "etc/network/interfaces" in found:
-        fn = found["etc/network/interfaces"]
-        md['network_config'] = util.load_file(fn)
-
-    if "root/.ssh/authorized_keys" in found:
-        fn = found["root/.ssh/authorized_keys"]
-        keydata = util.load_file(fn)
-
-    meta_js = {}
-    if "meta.js" in found:
-        fn = found['meta.js']
-        content = util.load_file(fn)
-        try:
-            # Just check if its really json...
-            meta_js = json.loads(content)
-            if not isinstance(meta_js, (dict)):
-                raise TypeError("Dict expected for meta.js root node")
-        except (ValueError, TypeError) as e:
-            raise NonConfigDriveDir("%s: %s, %s" %
-                (source_dir, "invalid json in meta.js", e))
-        md['meta_js'] = content
-
-    # keydata in meta_js is preferred over "injected"
-    keydata = meta_js.get('public-keys', keydata)
-    if keydata:
-        lines = keydata.splitlines()
-        md['public-keys'] = [l for l in lines
-            if len(l) and not l.startswith("#")]
-
-    # config-drive-v1 has no way for openstack to provide the instance-id
-    # so we copy that into metadata from the user input
-    if 'instance-id' in meta_js:
-        md['instance-id'] = meta_js['instance-id']
-
-    results = {'cfgdrive_ver': 1, 'metadata': md}
-
-    # allow the user to specify 'dsmode' in a meta tag
-    if 'dsmode' in meta_js:
-        results['dsmode'] = meta_js['dsmode']
-
-    # config-drive-v1 has no way of specifying user-data, so the user has
-    # to cheat and stuff it in a meta tag also.
-    results['userdata'] = meta_js.get('user-data')
-
-    # this implementation does not support files
-    # (other than network/interfaces and authorized_keys)
-    results['files'] = []
-
-    return results
-
-
 def get_ds_mode(cfgdrv_ver, ds_cfg=None, user=None):
     """Determine what mode should be used.
     valid values are 'pass', 'disabled', 'local', 'net'
@@ -483,6 +160,21 @@ def get_ds_mode(cfgdrv_ver, ds_cfg=None, user=None):
     return "net"
 
 
+def read_config_drive(source_dir, version="2012-08-10"):
+    reader = openstack.ConfigDriveReader(source_dir)
+    finders = [
+        (reader.read_v2, [], {'version': version}),
+        (reader.read_v1, [], {}),
+    ]
+    excps = []
+    for (functor, args, kwargs) in finders:
+        try:
+            return functor(*args, **kwargs)
+        except openstack.NonReadable as e:
+            excps.append(e)
+    raise excps[-1]
+
+
 def get_previous_iid(paths):
     # interestingly, for this purpose the "previous" instance-id is the current
     # instance-id.  cloud-init hasn't moved them over yet as this datasource
@@ -494,17 +186,79 @@ def get_previous_iid(paths):
         return None
 
 
-def write_files(files):
-    for (name, content) in files.iteritems():
-        if name[0] != os.sep:
-            name = os.sep + name
-        util.write_file(name, content, mode=0660)
+def on_first_boot(data, distro=None):
+    """Performs any first-boot actions using data read from a config-drive."""
+    if not isinstance(data, dict):
+        raise TypeError("Config-drive data expected to be a dict; not %s"
+                        % (type(data)))
+    net_conf = data.get("network_config", '')
+    if net_conf and distro:
+        LOG.debug("Updating network interfaces from config drive")
+        distro.apply_network(net_conf)
+    files = data.get('files', {})
+    if files:
+        LOG.debug("Writing %s injected files", len(files))
+        for (filename, content) in files.iteritems():
+            if not filename.startswith(os.sep):
+                filename = os.sep + filename
+            try:
+                util.write_file(filename, content, mode=0660)
+            except IOError:
+                util.logexc(LOG, "Failed writing file: %s", filename)
+
+
+def find_candidate_devs(probe_optical=True):
+    """Return a list of devices that may contain the config drive.
+
+    The returned list is sorted by search order where the first item has
+    should be searched first (highest priority)
+
+    config drive v1:
+       Per documentation, this is "associated as the last available disk on the
+       instance", and should be VFAT.
+       Currently, we do not restrict search list to "last available disk"
+
+    config drive v2:
+       Disk should be:
+        * either vfat or iso9660 formated
+        * labeled with 'config-2'
+    """
+    # query optical drive to get it in blkid cache for 2.6 kernels
+    if probe_optical:
+        for device in OPTICAL_DEVICES:
+            try:
+                util.find_devs_with(path=device)
+            except util.ProcessExecutionError:
+                pass
+
+    by_fstype = []
+    for fs_type in FS_TYPES:
+        by_fstype.extend(util.find_devs_with("TYPE=%s" % (fs_type)))
+
+    by_label = []
+    for label in LABEL_TYPES:
+        by_label.extend(util.find_devs_with("LABEL=%s" % (label)))
+
+    # give preference to "last available disk" (vdb over vda)
+    # note, this is not a perfect rendition of that.
+    by_fstype.sort(reverse=True)
+    by_label.sort(reverse=True)
+
+    # combine list of items by putting by-label items first
+    # followed by fstype items, but with dupes removed
+    candidates = (by_label + [d for d in by_fstype if d not in by_label])
+
+    # We are looking for a block device or partition with necessary label or
+    # an unpartitioned block device (ex sda, not sda1)
+    devices = [d for d in candidates
+               if d in by_label or not util.is_partition(d)]
+    return devices
 
 
 # Used to match classes to dependencies
 datasources = [
-  (DataSourceConfigDrive, (sources.DEP_FILESYSTEM, )),
-  (DataSourceConfigDriveNet, (sources.DEP_FILESYSTEM, sources.DEP_NETWORK)),
+    (DataSourceConfigDrive, (sources.DEP_FILESYSTEM, )),
+    (DataSourceConfigDriveNet, (sources.DEP_FILESYSTEM, sources.DEP_NETWORK)),
 ]