Add automatic schema upgrade to nodes

Performs an automatic schema upgrade when all nodes are updated to the
latest version.

Addresses #129

daemon-common/migrations/versions/0.json

@@ -1 +1 @@
-{"version": "0", "root": "", "base": {"schema": "/schema", "schema.version": "/schema/version", "config": "/config", "config.maintenance": "/config/maintenance", "config.primary_node": "/config/primary_node", "config.upstream_ip": "/config/upstream_ip", "config.migration_target_selector": "/config/migration_target_selector", "lock": "/locks", "lock.primary_node": "/locks/primary_node", "lock.flush_lock": "/locks/flush_lock", "lock.domain_migrate": "/locks/domain_migrate", "cmd": "/cmd", "cmd.nodes": "/cmd/nodes", "cmd.domains": "/cmd/domains", "cmd.ceph": "/cmd/ceph", "node": "/nodes", "domain": "/domains", "network": "/networks", "storage": "/ceph", "storage.util": "/ceph/util", "osd": "/ceph/osds", "pool": "/ceph/pools", "volume": "/ceph/volumes", "snapshot": "/ceph/snapshots"}, "node": {"keepalive": "/keepalive", "mode": "/daemonmode", "data.active_schema": "/activeschema", "data.static": "/staticdata", "counts.provisioned_domains": "/domainscount", "counts.running_domains": "/runningdomains", "counts.networks": "/networkscount", "state.daemon": "/daemonstate", "state.router": "/routerstate", "state.domain": "/domainstate", "vcpu.allocated": "/vcpualloc", "memory.total": "/memtotal", "memory.used": "/memused", "memory.free": "/memfree", "memory.allocated": "/memalloc", "memory.provisioned": "/memprov", "ipmi.hostname": "/ipmihostname", "ipmi.username": "/ipmiusername", "ipmi.password": "/ipmipassword"}, "domain": {"name": "", "xml": "/xml", "state": "/state", "profile": "/profile", "stats": "/stats", "node": "/node", "last_node": "/lastnode", "failed_reason": "/failedreason", "console.log": "/consolelog", "console.vnc": "/vnc", "meta.autostart": "/node_autostart", "meta.migrate_method": "/migration_method", "meta.node_selector": "/node_selector", "meta.node_limit": "/node_limit"}, "network": {"type": "/nettype", "rules": "/firewall_rules", "nameservers": "/name_servers", "domain": "/domain", "ip4.gateway": "/ip4_gateway", "ip4.network": "/ip4_network", "ip4.dhcp": "/dhcp4_flag", "ip4.reservations": "/dhcp4_reservations", "ip4.dhcp_start": "/dhcp4_start", "ip4.dhcp_end": "/dhcp4_end", "ip6.gateway": "/ip6_gateway", "ip6.network": "/ip6_network", "ip6.dhcp": "/dhcp6_flag"}, "osd": {"node": "/node", "device": "/device", "stats": "/stats"}, "pool": {"pgs": "/pgs", "stats": "/stats"}, "volume": {"stats": "/stats"}, "snapshot": {"stats": "/stats"}}
+{"version": "0", "root": "", "base": {"schema": "/schema", "schema.version": "/schema/version", "config": "/config", "config.maintenance": "/config/maintenance", "config.primary_node": "/config/primary_node", "config.upstream_ip": "/config/upstream_ip", "config.migration_target_selector": "/config/migration_target_selector", "lock": "/locks", "lock.primary_node": "/locks/primary_node", "lock.flush_lock": "/locks/flush_lock", "lock.domain_migrate": "/locks/domain_migrate", "cmd": "/cmd", "cmd.nodes": "/cmd/nodes", "cmd.domains": "/cmd/domains", "cmd.ceph": "/cmd/ceph", "node": "/nodes", "domain": "/domains", "network": "/networks", "storage": "/ceph", "storage.util": "/ceph/util", "osd": "/ceph/osds", "pool": "/ceph/pools", "volume": "/ceph/volumes", "snapshot": "/ceph/snapshots"}, "node": {"keepalive": "/keepalive", "mode": "/daemonmode", "data.active_schema": "/activeschema", "data.latest_schema": "/latestschema", "data.static": "/staticdata", "counts.provisioned_domains": "/domainscount", "counts.running_domains": "/runningdomains", "counts.networks": "/networkscount", "state.daemon": "/daemonstate", "state.router": "/routerstate", "state.domain": "/domainstate", "vcpu.allocated": "/vcpualloc", "memory.total": "/memtotal", "memory.used": "/memused", "memory.free": "/memfree", "memory.allocated": "/memalloc", "memory.provisioned": "/memprov", "ipmi.hostname": "/ipmihostname", "ipmi.username": "/ipmiusername", "ipmi.password": "/ipmipassword"}, "domain": {"name": "", "xml": "/xml", "state": "/state", "profile": "/profile", "stats": "/stats", "node": "/node", "last_node": "/lastnode", "failed_reason": "/failedreason", "console.log": "/consolelog", "console.vnc": "/vnc", "meta.autostart": "/node_autostart", "meta.migrate_method": "/migration_method", "meta.node_selector": "/node_selector", "meta.node_limit": "/node_limit"}, "network": {"type": "/nettype", "rules": "/firewall_rules", "nameservers": "/name_servers", "domain": "/domain", "ip4.gateway": "/ip4_gateway", "ip4.network": "/ip4_network", "ip4.dhcp": "/dhcp4_flag", "ip4.reservations": "/dhcp4_reservations", "ip4.dhcp_start": "/dhcp4_start", "ip4.dhcp_end": "/dhcp4_end", "ip6.gateway": "/ip6_gateway", "ip6.network": "/ip6_network", "ip6.dhcp": "/dhcp6_flag"}, "osd": {"node": "/node", "device": "/device", "stats": "/stats"}, "pool": {"pgs": "/pgs", "stats": "/stats"}, "volume": {"stats": "/stats"}, "snapshot": {"stats": "/stats"}}

daemon-common/zkhandler.py

@@ -402,6 +402,7 @@ class ZKSchema(object):
             'keepalive': '/keepalive',
             'mode': '/daemonmode',
             'data.active_schema': '/activeschema',
+            'data.latest_schema': '/latestschema',
             'data.static': '/staticdata',
             'counts.provisioned_domains': '/domainscount',
             'counts.running_domains': '/runningdomains',
@@ -724,10 +725,6 @@ class ZKSchema(object):
             print(changes)
             # Apply those changes
             self.run_migrate(zkhandler, changes)
-            # Update the schema version key
-            zkhandler.write([
-                (self.key('base.schema.version'), zkschema_new.version)
-            ])
 
     # Rollback from newer to older schema
     def rollback(self, zkhandler, old_version):
@@ -812,3 +809,12 @@ class ZKSchema(object):
             return versions
         else:
             return None
+
+    @staticmethod
+    def find_latest():
+        latest_version = 0
+        for version in os.listdir('daemon_lib/migrations/versions'):
+            sequence_id = int(version.split('.')[0])
+            if sequence_id > latest_version:
+                latest_version = sequence_id
+        return latest_version

node-daemon/pvcnoded/Daemon.py

@@ -21,7 +21,6 @@
 
 import kazoo.client
 import libvirt
-import sys
 import os
 import signal
 import psutil
@@ -74,6 +73,9 @@ version = '0.9.19'
 # Daemon functions
 ###############################################################################
 
+# Ensure the update_timer is None until it's set for real
+update_timer = None
+
 
 # Create timer to update this node in Zookeeper
 def startKeepaliveTimer():
@@ -542,8 +544,15 @@ except Exception:
         (zkschema.path('node.data.active_schema', myhostname), node_schema_version)
     ])
 
+# Load in the current node schema version
 zkschema.load(node_schema_version)
 
+# Record the latest intalled schema version
+latest_schema_version = ZKSchema.find_latest()
+zkhandler.write([
+    (zkschema.path('node.data.latest_schema', myhostname), latest_schema_version)
+])
+
 # Validate our schema against that version
 if not zkschema.validate(zkhandler, logger):
     logger.out('Found schema violations, applying', state='i')
@@ -552,6 +561,80 @@ else:
     logger.out('Schema successfully validated', state='o')
 
 
+# Watch for a global schema update and fire
+# This will only change by the API when triggered after seeing all nodes can update
+@zkhandler.zk_conn.DataWatch(zkschema.path('base.schema.version'))
+def update_schema(new_schema_version, stat, event=''):
+    global zkschema, zkhandler, update_timer
+
+    new_schema_version = int(new_schema_version.decode('ascii'))
+
+    if new_schema_version == node_schema_version:
+        return
+
+    logger.out('Hot update of schema version started', state='s')
+
+    # Prevent any keepalive updates while this happens
+    if update_timer is not None:
+        stopKeepaliveTimer()
+
+    # Perform the migration (primary only)
+    if zkhandler.read(zkschema.path('base.config.primary_node')) == myhostname:
+        logger.out('Primary node acquiring exclusive lock', state='s')
+        # Wait for things to settle
+        time.sleep(0.5)
+        # Acquire a write lock on the root key
+        with zkhandler.exclusivelock('/'):
+            # Perform the schema migration tasks
+            logger.out('Performing schema update', state='s')
+            zkschema.migrate(zkhandler, latest_schema_version)
+    # Wait for the exclusive lock to be lifted
+    else:
+        logger.out('Non-primary node acquiring read lock', state='s')
+        # Wait for things to settle
+        time.sleep(1)
+        # Wait for a read lock
+        lock = zkhandler.readlock('/')
+        lock.acquire()
+        # Wait a bit more for the primary to return to normal
+        time.sleep(1)
+
+    # Update the local schema version
+    logger.out('Updating local schema', state='s')
+    zkschema.load(new_schema_version)
+    zkhandler.write([
+        (zkschema.path('node.data.active_schema', myhostname), new_schema_version)
+    ])
+
+    # Restart the zookeeper connection
+    logger.out('Restarting Zookeeper connection', state='s')
+    zkhandler.disconnect()
+    time.sleep(1)
+    zkhandler.connect(persistent=True)
+
+    # Restart the update timer
+    if update_timer is not None:
+        update_timer = startKeepaliveTimer()
+
+    # Restart the API daemons if applicable
+    if zkhandler.read(zkschema.path('base.config.primary_node')) == myhostname:
+        common.run_os_command('systemctl start pvcapid.service')
+        common.run_os_command('systemctl start pvcapid-worker.service')
+
+
+# If we are the last node to get a schema update, fire the master update
+if latest_schema_version > node_schema_version:
+    node_latest_schema_version = list()
+    for node in zkhandler.children(zkschema.path('base.node')):
+        node_latest_schema_version.append(zkhandler.read(zkschema.path('node.data.latest_schema', node)))
+
+    # This is true if all elements of the latest schema version are identical to the latest version,
+    # i.e. they have all had the latest schema installed and ready to load.
+    if node_latest_schema_version.count(latest_schema_version) == len(node_latest_schema_version):
+        zkhandler.write([
+            (zkschema.path('base.schema.version'), latest_schema_version)
+        ])
+
 ###############################################################################
 # PHASE 5 - Gracefully handle termination
 ###############################################################################
@@ -624,7 +707,7 @@ def cleanup():
         pass
 
     logger.out('Terminated pvc daemon', state='s')
-    sys.exit(0)
+    os._exit(0)
 
 
 # Termination function

node-daemon/test-schema.py

@@ -1,43 +0,0 @@
-#!/usr/bin/env python3
-
-# flake8: noqa
-
-import sys
-import datetime
-from daemon_lib.zkhandler import ZKHandler, ZKSchema
-
-ZKSchema.write()
-
-sys.exit(0)
-
-print(datetime.datetime.now())
-zkhandler = ZKHandler({'coordinators': ['hv1.tc', 'hv2.tc', 'hv3.tc']})
-zkhandler.connect()
-print(datetime.datetime.now())
-
-zkschema = ZKSchema.load_current(zkhandler)
-
-#print(zkschema.path('base.schema.version'))
-#print(zkschema.path('node.state.daemon', 'hv1'))
-#print(zkschema.path('domain.state', 'test1'))
-#print(zkschema.keys('base'))
-#print(zkschema.keys('node'))
-
-
-zkschema.validate(zkhandler)
-zkschema.apply(zkhandler)
-
-zkschema_latest = ZKSchema()
-#if zkschema < zkschema_latest:
-#    print("I'm older")
-#elif zkschema == zkschema_latest:
-#    print("I'm the same")
-#elif zkschema > zkschema_latest:
-#    print("I'm newer")
-
-#diff = ZKSchema.key_diff(zkschema, zkschema_latest)
-zkschema.migrate(zkhandler, zkschema_latest.version)
-
-#zkschema_earliest = ZKSchema()
-#zkschema_earliest.load(0)
-#zkschema.rollback(zkhandler, zkschema_earliest.version)