SDN Accounts refactoring
[osm/SO.git] / common / python / rift / mano / sdn / config.py
diff --git a/common/python/rift/mano/sdn/config.py b/common/python/rift/mano/sdn/config.py
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+
+#
+#   Copyright 2017 RIFT.IO Inc
+#
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+#
+
+import asyncio
+
+import gi
+gi.require_version('RwDts', '1.0')
+import rift.tasklets
+
+from gi.repository import (
+    RwDts as rwdts,
+    ProtobufC,
+    )
+
+from . import accounts
+
+
+class SDNAccountNotFound(Exception):
+    pass
+
+
+class SDNAccountError(Exception):
+    pass
+
+
+def get_add_delete_update_cfgs(dts_member_reg, xact, key_name):
+    # Unforunately, it is currently difficult to figure out what has exactly
+    # changed in this xact without Pbdelta support (RIFT-4916)
+    # As a workaround, we can fetch the pre and post xact elements and
+    # perform a comparison to figure out adds/deletes/updates
+    xact_cfgs = list(dts_member_reg.get_xact_elements(xact))
+    curr_cfgs = list(dts_member_reg.elements)
+
+    xact_key_map = {getattr(cfg, key_name): cfg for cfg in xact_cfgs}
+    curr_key_map = {getattr(cfg, key_name): cfg for cfg in curr_cfgs}
+
+    # Find Adds
+    added_keys = set(xact_key_map) - set(curr_key_map)
+    added_cfgs = [xact_key_map[key] for key in added_keys]
+
+    # Find Deletes
+    deleted_keys = set(curr_key_map) - set(xact_key_map)
+    deleted_cfgs = [curr_key_map[key] for key in deleted_keys]
+
+    # Find Updates
+    updated_keys = set(curr_key_map) & set(xact_key_map)
+    updated_cfgs = [xact_key_map[key] for key in updated_keys if xact_key_map[key] != curr_key_map[key]]
+
+    return added_cfgs, deleted_cfgs, updated_cfgs
+
+
+class SDNAccountConfigCallbacks(object):
+    def __init__(self,
+                 on_add_apply=None, on_add_prepare=None,
+                 on_delete_apply=None, on_delete_prepare=None):
+
+        @asyncio.coroutine
+        def prepare_noop(*args, **kwargs):
+            pass
+
+        def apply_noop(*args, **kwargs):
+            pass
+
+        self.on_add_apply = on_add_apply
+        self.on_add_prepare = on_add_prepare
+        self.on_delete_apply = on_delete_apply
+        self.on_delete_prepare = on_delete_prepare
+
+        for f in ('on_add_apply', 'on_delete_apply'):
+            ref = getattr(self, f)
+            if ref is None:
+                setattr(self, f, apply_noop)
+                continue
+
+            if asyncio.iscoroutinefunction(ref):
+                raise ValueError('%s cannot be a coroutine' % (f,))
+
+        for f in ('on_add_prepare', 'on_delete_prepare'):
+            ref = getattr(self, f)
+            if ref is None:
+                setattr(self, f, prepare_noop)
+                continue
+
+            if not asyncio.iscoroutinefunction(ref):
+                raise ValueError("%s must be a coroutine" % f)
+
+
+class SDNAccountConfigSubscriber(object):
+    XPATH = "C,/rw-sdn:sdn/rw-sdn:account"
+
+    def __init__(self, dts, log, rwlog_hdl, sdn_callbacks, acctstore):
+        self._dts = dts
+        self._log = log
+        self._rwlog_hdl = rwlog_hdl
+        self._reg = None
+
+        self.accounts = acctstore
+
+        self._sdn_callbacks = sdn_callbacks
+
+    def add_account(self, account_msg):
+        self._log.info("adding sdn account: {}".format(account_msg))
+
+        account = accounts.SDNAccount(self._log, self._rwlog_hdl, account_msg)
+        self.accounts[account.name] = account
+
+        self._sdn_callbacks.on_add_apply(account)
+
+    def delete_account(self, account_name):
+        self._log.info("deleting sdn account: {}".format(account_name))
+        del self.accounts[account_name]
+
+        self._sdn_callbacks.on_delete_apply(account_name)
+
+    def update_account(self, account_msg):
+        """ Update an existing sdn account
+
+        In order to simplify update, turn an update into a delete followed by
+        an add.  The drawback to this approach is that we will not support
+        updates of an "in-use" sdn account, but this seems like a
+        reasonable trade-off.
+
+
+        Arguments:
+            account_msg - The sdn account config message
+        """
+        self._log.info("updating sdn account: {}".format(account_msg))
+
+        self.delete_account(account_msg.name)
+        self.add_account(account_msg)
+
+    def register(self):
+        @asyncio.coroutine
+        def apply_config(dts, acg, xact, action, _):
+            self._log.debug("Got sdn account apply config (xact: %s) (action: %s)", xact, action)
+
+            if xact.xact is None:
+                if action == rwdts.AppconfAction.INSTALL:
+                    curr_cfg = self._reg.elements
+                    for cfg in curr_cfg:
+                        self._log.debug("SDN account being re-added after restart.")
+                        if not cfg.has_field('account_type'):
+                            raise SDNAccountError("New SDN account must contain account_type field.")
+                        self.add_account(cfg)
+                else:
+                    # When RIFT first comes up, an INSTALL is called with the current config
+                    # Since confd doesn't actally persist data this never has any data so
+                    # skip this for now.
+                    self._log.debug("No xact handle.  Skipping apply config")
+
+                return
+
+            add_cfgs, delete_cfgs, update_cfgs = get_add_delete_update_cfgs(
+                    dts_member_reg=self._reg,
+                    xact=xact,
+                    key_name="name",
+                    )
+
+            # Handle Deletes
+            for cfg in delete_cfgs:
+                self.delete_account(cfg.name)
+
+            # Handle Adds
+            for cfg in add_cfgs:
+                self.add_account(cfg)
+
+            # Handle Updates
+            for cfg in update_cfgs:
+                self.update_account(cfg)
+
+        @asyncio.coroutine
+        def on_prepare(dts, acg, xact, xact_info, ks_path, msg, scratch):
+            """ Prepare callback from DTS for SDN Account """
+
+            action = xact_info.query_action
+            self._log.debug("SDN account on_prepare config received (action: %s): %s",
+                            xact_info.query_action, msg)
+
+            if action in [rwdts.QueryAction.CREATE, rwdts.QueryAction.UPDATE]:
+                if msg.name in self.accounts:
+                    self._log.debug("SDN account already exists. Invoking update request")
+
+                    # Since updates are handled by a delete followed by an add, invoke the
+                    # delete prepare callbacks to give clients an opportunity to reject.
+                    yield from self._sdn_callbacks.on_delete_prepare(msg.name)
+
+                else:
+                    self._log.debug("SDN account does not already exist. Invoking on_prepare add request")
+                    if not msg.has_field('account_type'):
+                        raise SDNAccountError("New sdn account must contain account_type field.")
+
+                    account = accounts.SDNAccount(self._log, self._rwlog_hdl, msg)
+                    yield from self._sdn_callbacks.on_add_prepare(account)
+
+            elif action == rwdts.QueryAction.DELETE:
+                # Check if the entire SDN account got deleted
+                fref = ProtobufC.FieldReference.alloc()
+                fref.goto_whole_message(msg.to_pbcm())
+                if fref.is_field_deleted():
+                    yield from self._sdn_callbacks.on_delete_prepare(msg.name)
+
+                else:
+                    self._log.error("Deleting individual fields for SDN account not supported")
+                    xact_info.respond_xpath(rwdts.XactRspCode.NACK)
+                    return
+
+            else:
+                self._log.error("Action (%s) NOT SUPPORTED", action)
+                xact_info.respond_xpath(rwdts.XactRspCode.NACK)
+
+            xact_info.respond_xpath(rwdts.XactRspCode.ACK)
+
+        self._log.debug("Registering for SDN Account config using xpath: %s",
+                        SDNAccountConfigSubscriber.XPATH,
+                        )
+
+        acg_handler = rift.tasklets.AppConfGroup.Handler(
+                        on_apply=apply_config,
+                        )
+
+        with self._dts.appconf_group_create(acg_handler) as acg:
+            self._reg = acg.register(
+                    xpath=SDNAccountConfigSubscriber.XPATH,
+                    flags=rwdts.Flag.SUBSCRIBER | rwdts.Flag.DELTA_READY | rwdts.Flag.CACHE,
+                    on_prepare=on_prepare,
+                    )